204 results on '"Tozuka Y"'
Search Results
2. Density functional theory study of equimolar complexation of urea or thiourea with 2-alcoxybenzamide
- Author
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Hata, M., Moribe, K., Ando, S., Tozuka, Y., and Yamamoto, K.
- Published
- 2014
- Full Text
- View/download PDF
3. Nanoparticle formation from probucol/PVP/sodium alkyl sulfate co-ground mixture
- Author
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Wanawongthai, C., Pongpeerapat, A., Higashi, K., Tozuka, Y., Moribe, K., and Yamamoto, K.
- Published
- 2009
- Full Text
- View/download PDF
4. Improvement of physicochemical properties of N-4472 part I formulation design by using self-microemulsifying system
- Author
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Itoh, K, Tozuka, Y, Oguchi, T, and Yamamoto, K
- Published
- 2002
- Full Text
- View/download PDF
5. Cocrystal structure design for CH5134731 based on isomorphism
- Author
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Tanida, S., primary, Takata, N., additional, Takano, R., additional, Sakon, A., additional, Ueto, T., additional, Shiraki, K., additional, Kadota, K., additional, Tozuka, Y., additional, and Ishigai, M., additional
- Published
- 2018
- Full Text
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6. Adsorption state of naphthoic acids on folded sheets mesoporous materials with different pore sizes
- Author
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Tozuka, Y., Yokohama, C., Higashi, K., Moribe, K., and Yamamoto, K.
- Published
- 2009
- Full Text
- View/download PDF
7. The rare crystallographic structure of d(CGCGCG)2: The natural spermidine molecule bound to the minor groove of left-handed Z-DNA d(CGCGCG)2 at 10 degree celsius
- Author
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Ohishi, H., primary, Tozuka, Y., additional, Da-Yang, Z., additional, Ishida, T., additional, and Nakatani, K., additional
- Published
- 2008
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8. Micronization and Polymorphic Conversion of Tolbutamide and Barbital by Rapid Expansion of Supercritical Solutions
- Author
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Shinozaki, H., primary, Oguchi, T., additional, Suzuki, S., additional, Aoki, K., additional, Sako, T., additional, Morishita, S., additional, Tozuka, Y., additional, Moribe, K., additional, and Yamamoto, K., additional
- Published
- 2006
- Full Text
- View/download PDF
9. Formation and stability of drug nanoparticles obtained from drug/PVP/SDS ternary ground mixture
- Author
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Pongpeerapat, A., primary, Itoh, K., additional, Tozuka, Y., additional, Moribe, K., additional, Oguchi, T., additional, and Yamamoto, K., additional
- Published
- 2004
- Full Text
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10. Dynamic behaviour of sulfur forms in rapid pyrolysis of density-separated coals
- Author
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SUGAWARA, K, primary, TOZUKA, Y, additional, KAMOSHITA, T, additional, SUGAWARA, T, additional, and SHOLES, M, additional
- Published
- 1994
- Full Text
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11. Effect of heating rate and temperature on pyrolysis desulfurization of a bituminous coal
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Sugawara, K., Tozuka, Y., Sugawara, T., and Nishiyama, Y.
- Published
- 1994
- Full Text
- View/download PDF
12. Improvement of physicochemical properties of N-4472: Part II: characterization of N-4472 microemulsion and the enhanced oral absorption
- Author
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Itoh, K., Matsui, S., Tozuka, Y., Oguchi, T., and Yamamoto, K.
- Subjects
- *
DRUG solubility , *VITAMIN C , *NUCLEAR magnetic resonance spectroscopy - Abstract
The optimized formulation of N-4472, N-[2-(3,5-di-tert-butyl-4-hydroxyphenethyl)-4,6-difluorophenyl]-N′-[4-(N-benzylpiperidyl)] urea, which was a poorly water-soluble drug, was developed by utilizing the complexation between N-4472 and l-ascorbic acid (VC). It was found that the formulation with Gelucire® 44/14, HCO-60® and sodium dodecyl sulfate provided a self-microemulsifying system consisting of fine droplets in approximately 18 nm size with a narrow distribution. 1H-NMR spectroscopic study indicated that the N-4472/VC complex was molecularly incorporated into surfactant molecular assembly in the microemulsion droplets. It was found that the N-4472 microemulsion was stable at the pH range from 2.0 to 7.0, suggesting the stability in the gastrointestinal tract. When the microemulsion containing N-4472/VC complex was orally administrated in rats, high AUC value of N-4472 (2 to 4-fold) was observed in comparison with the aqueous solution containing N-4472/VC complex. [Copyright &y& Elsevier]
- Published
- 2002
- Full Text
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13. Amyloid Nanofibril-Assisted Spray Drying of Crumpled Supraparticles.
- Author
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Kämäräinen T, Nakayama Y, Uchiyama H, Tozuka Y, and Kadota K
- Abstract
Nanofibrils are known to improve the cohesion of supraparticle (SP) assemblies. However, tailoring the morphology of SPs using nanofibrillar additives is not well developed. Herein, β-lactoglobulin amyloid nanofibrils (ANFs) are investigated as means to impart morphological control over the assembly process of spray-dried SPs composed of 10-100 nm silica nanoparticles (SiNPs). Phytoglycogen (PG) and silver nanowires (AgNWs) are used to assess the influence of building block softness and aspect ratio, respectively. The results demonstrate that ANFs promote the onset of structural arrest during the particle consolidation enabling the preparation of corrugated SP morphologies. The critical ANF loading required to induce SP corrugation increases by roughly 1 vol% for every 10-nm increase in SiNP diameter, while the ensuing ANF network density decreases with SiNP volume fraction and increases with SiNP diameter. Results imply that ANF length starts to become influential when it approaches the SiNP diameter. ANFs display a reduced effectiveness in altering soft PG SP morphology compared with hard SiNPs of comparable size. In SiNP-AgNW SPs, ANFs induce a toroid-to-corrugated morphology transformation for sufficiently large SPs and small SiNPs. The results illustrate that ANFs are effective additives for the morphological engineering of spray-dried SPs important for numerous applications., (© 2024 Wiley‐VCH GmbH.)
- Published
- 2024
- Full Text
- View/download PDF
14. Multiscale structure analysis of a pH-responsive gelatin/hydroxypropyl methylcellulose phthalate blend using small-angle scattering.
- Author
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Kämäräinen T, Nogami S, Arima-Osonoi H, Iwase H, Uchiyama H, Tozuka Y, and Kadota K
- Subjects
- Hydrogen-Ion Concentration, Hydrogels chemistry, Molecular Structure, Gelatin chemistry, Scattering, Small Angle, Methylcellulose chemistry, Methylcellulose analogs & derivatives, Particle Size
- Abstract
Hypothesis: Hydroxypropyl methylcellulose phthalate (HPMCP) is an enteric polymer that has been employed in drug delivery systems to delay the release of the encapsulated active pharmaceutical ingredients through its pH-responsive solubility change. This has been recently demonstrated as an effective means for delaying the drug release from gelatin/HPMCP hydrogels at gastric pH values. However, structural characteristics of HPMCP agglomeration in gelatin/HPMCP hydrogels is not well understood thus limiting further tailoring of their material properties., Experiments: We investigated the multiscale structure of a gelatin/HPMCP hydrogel (1:1 by weight) between pH 2 and 6 at 37 °C, i.e. above the upper critical solution transition temperature of gelatin, using small-angle X-ray scattering and contrast-variation small-angle neutron scattering to understand the pH-responsive structure of HPMCP and the cross-correlation between gelatin and HPMCP., Findings: Agglomeration of HPMCP between pH 2 and 4 was evidenced by the formation of mass fractal structures, with a fractal dimension ranging from 1.5 to 2.7, comprising primary particles with a radius of gyration ranging from 70 to 140 Å. Blending with gelatin influenced the fractal structure of HPMCP and the primary particle size. Gelatin and HPMCP exhibited negative cross-correlation in all probed length scales and pH values, which was attributed to volume-exclusion interaction in a double-network-like solution architecture., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
- Full Text
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15. Endoscopic ultrasound-guided gallbladder drainage using a forward-viewing echoendoscope after Billroth II gastrectomy.
- Author
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Tozuka Y, Sugimori K, Miwa H, Kaneko T, Ueno M, Furuse J, and Maeda S
- Subjects
- Humans, Drainage, Endosonography, Gastrectomy, Ultrasonography, Interventional, Gallbladder diagnostic imaging, Gallbladder surgery, Gastroenterostomy
- Abstract
Competing Interests: The authors declare that they have no conflict of interest.
- Published
- 2024
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16. Tailored Sugar-Mediated Porous Particle Structures for Improved Dispersion of Drug Nanoparticles in Spray-Freeze-Drying.
- Author
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Semba K, Kadota K, Kämäräinen T, Nakayama Y, Hatanaka Y, Uchiyama H, Arima-Osonoi H, Sugiyama K, and Tozuka Y
- Abstract
We fabricated porous particles incorporating sugars (mannitol, sucrose, or dextran) and fenofibrate nanoparticles (FNPs) by using spray-freeze-drying (SFD). The type of sugar significantly influenced the pore architecture of the resulting SFD particles. Rapid freezing of droplets containing dextran produced ice encapsulation within a dextran matrix, forming porous dextran particles. In the presence of FNPs, the particle size (approximately 4 μm) and pore volume (0.3 cm
3 /g) of SFD dextran were barely affected. In contrast, SFD particles derived from mannitol and sucrose exhibited denser structures with a lower pore volume than dextran. SFD mannitol incorporating FNPs produced porous structures. FNPs containing surfactant and polymer, which reduced surface tension and increased viscosity, promoted the formation of small droplets with a polymeric structure and porous particles with a relatively sharp size distribution with a median around 5 μm. FNPs were uniformly distributed in SFD dextran, which featured large pore structures, whereas in SFD mannitol, the Raman signal of FNPs was more broadly distributed across the powder samples. Both morphologies contributed to enhancing the FNP dispersibility within a redispersed suspension of SFD particles. FNPs in SFD mannitol and dextran matrices maintained their particle size distribution from before SFD, showing no aggregation upon redispersion. Dextran formed a highly porous network irrespective of the presence of FNPs, whereas mannitol tended to alter the particle attributes upon FNP inclusion. In conclusion, SFD particles derived from dextran and mannitol might help to increase FNP dispersibility by increasing the formation of porous architectures.- Published
- 2024
- Full Text
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17. Solubilization mechanism of α-glycosylated naringin based on self-assembled nanostructures and its application to skin formulation.
- Author
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Uchiyama H, Minoura K, Yamada E, Ando K, Yamauchi R, Nakanishi A, Tandia M, Kadota K, and Tozuka Y
- Subjects
- Glycosylation, Animals, Skin Absorption drug effects, Administration, Cutaneous, Flavones chemistry, Permeability, Magnetic Resonance Spectroscopy methods, Flavanones chemistry, Solubility, Nanostructures chemistry, Skin metabolism
- Abstract
We previously reported that α-glycosylated naringin (naringin-G), synthesized by enzyme-catalyzed transglycosylation, can enhance the solubility of poorly water-soluble compounds without surface-active property. However, the solubilization mechanism has not been fully elucidated. In this study, the solubilization mechanism of naringin-G was investigated using nuclear magnetic resonance (NMR) spectroscopy, and its application in skin formulations was further investigated.
1 H NMR and dynamic light scattering measurements at various concentrations confirmed the self-assembled nanostructures of naringin-G above a critical aggregation concentration of approximately 2.2 mg/mL. Two-dimensional1 H-1 H nuclear Overhauser effect spectroscopy and solubility tests revealed that flavone with poor water solubility, could be solubilized in its self-assembled structure with a stoichiometric relationship with naringin-G. When naringin-G was included in the skin formulation, the permeated amount and permeability coefficient (Papp ) of flavones improved up to four times with increasing amounts of naringin-G. However, flavone solubilization by adding an excessive amount of naringin-G resulted in a decreased permeated amount and Papp of flavones, indicating the interplay between the apparent solubility and skin permeability of flavones. Naringin-G, which forms a nanoaggregate structure without exhibiting surface-active properties, has the potential to enhance the solubility and skin permeation of poorly water-soluble compounds., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2024
- Full Text
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18. Building respirable powder architectures: utilizing polysaccharides for precise control of particle morphology for enhanced pulmonary drug delivery.
- Author
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Kadota K, Uchiyama H, Kämäräinen T, Tanaka S, and Tozuka Y
- Subjects
- Humans, Administration, Inhalation, Particle Size, Pharmaceutical Preparations administration & dosage, Pharmaceutical Preparations chemistry, Drug Compounding methods, Animals, Chemistry, Pharmaceutical, Metal-Organic Frameworks chemistry, Drug Delivery Systems, Dry Powder Inhalers, Polysaccharides chemistry, Powders, Lung metabolism, Excipients chemistry
- Abstract
Introduction: Dry powder inhaler (DPI) formulations are gaining attention as universal formulations with applications in a diverse range of drug formulations. The practical application of DPIs to pulmonary drugs requires enhancing their delivery efficiency to the target sites for various treatment modalities. Previous reviews have not explored the relation between particle morphology and delivery to different pulmonary regions. This review introduces new approaches to improve targeted DPI delivery using novel particle design such as supraparticles and metal-organic frameworks based on cyclodextrin., Areas Covered: This review focuses on the design of DPI formulations using polysaccharides, promising excipients not yet approved by regulatory agencies. These excipients can be used to design various particle morphologies by controlling their physicochemical properties and manufacturing methods., Expert Opinion: Challenges associated with DPI formulations include poor access to the lungs and low delivery efficiency to target sites in the lung. The restricted applicability of typical excipients contributes to their limited use. However, new formulations based on polysaccharides are expected to establish a technological foundation for the development of DPIs capable of delivering modalities specific to different lung target sites, thereby enhancing drug delivery.
- Published
- 2024
- Full Text
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19. The art and science of porous starch: understanding the preparation method and structure-function relationship.
- Author
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Kavya M, Krishnan R, Suvachan A, Sathyan S, Tozuka Y, Kadota K, and Nisha P
- Abstract
Porous starch (PS), a modified form of starch with unique properties, is attracting substantial attention for its diverse advantages and applications. Its intricate porous structure, crystalline and amorphous characteristics, and hydrophilic-hydrophobic properties stem from pore formation via physical, chemical, enzymatic, and combined synergistic methods. Porous starch offers benefits like improved gelatinization temperature, water absorption, increased surface area, tunable crystallinity, and enhanced functional properties, making it appealing for diverse food industry applications. To optimize its properties, determining the parameters governing porous structure formation is crucial. Factors such as processing conditions, starch source, and modification methods substantially impact porosity and the overall characteristics of the material. Understanding and controlling these parameters allows customization for specific applications, from pharmaceutical drug delivery systems to enhancing texture and moisture retention in food products. To date, studies shedding light on how porosity formation can be fine-tuned for specific applications are fewer. This review critically assesses the existing reports on porous starch, focusing on how preparation methods affect porosity formation, thereby influencing the product's crystallinity/hydrophilic-hydrophobic nature and overall applicability.
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- 2024
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20. Liposomal irinotecan plus fluorouracil/leucovorin in older patients with advanced pancreatic cancer: a single-center retrospective study.
- Author
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Nagashima S, Kobayashi S, Tsunoda S, Yamachika Y, Tozuka Y, Fukushima T, Morimoto M, Ueno M, Furuse J, and Maeda S
- Subjects
- Aged, Humans, Antineoplastic Combined Chemotherapy Protocols adverse effects, Fluorouracil therapeutic use, Irinotecan therapeutic use, Leucovorin therapeutic use, Liposomes therapeutic use, Retrospective Studies, Carcinoma, Pancreatic Ductal drug therapy, Pancreatic Neoplasms drug therapy
- Abstract
Background: The global phase 3 NAPOLI -1 trial of patients with pancreatic ductal adenocarcinoma (PDAC) demonstrated an overall survival (OS) benefit from using liposomal irinotecan and 5-fluorouracil/leucovorin (nal-IRI + 5-FU/LV) after treatment with gemcitabine (GEM) compared to 5-FU/LV alone. However, the efficacy and safety of this regimen in older patients are not well studied., Methods: We conducted a single-center retrospective study to compare the therapeutic efficacy of nal-IRI + 5-FU/LV between older and younger patients with cutoff ages of 70 and 75 years, respectively. We included patients with a prior history of one or more GEM-based regimens for locally advanced or metastatic PDAC and were treated with nal-IRI + 5-FU/LV., Results: Of the 115 patients, 54 (47.0%) and 24 (20.9%) were aged ≥ 70 and ≥ 75 years, respectively. The median OS and progression-free survival (PFS) of the entire cohort were 8.5 and 3.6 months, respectively. No significant differences were observed in OS and PFS hazard ratios using age cutoffs of 70 (P = 0.90 and 0.99, respectively) and 75 (P = 0.90 and 0.76, respectively) years. Additionally, no significant differences were found in the incidence of treatment-related adverse events (trAEs) between patients aged ≥ 70 and < 70 years or those aged ≥ 75 and < 75 years. Other than hematological toxicity, no trAEs higher than Grade 4 were observed in either age group., Conclusion: The efficacy and safety of nal-IRI + 5-FU/LV for patients with PDAC are not significantly different for those aged ≥ 70 years compared to younger patients., (© 2023. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.)
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- 2024
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21. The Impact of Adding a Cationic Metal Salt and Curcumin to Monoammonium Glycyrrhizic Acid on Its Solubilizing Capacity and Gelation.
- Author
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Ando K, Uchiyama H, Minoura K, Kadota K, and Tozuka Y
- Subjects
- Sodium Chloride chemistry, Potassium Chloride chemistry, Cations chemistry, Viscosity, Quaternary Ammonium Compounds chemistry, Glycyrrhizic Acid chemistry, Curcumin chemistry, Solubility, Gels chemistry, Micelles
- Abstract
Monoammonium glycyrrhizic acid (MAG), a glycyrrhizic acid monoammonium salt, is a naturally derived low-molecular-weight gelling agent with surface-active properties. It has the capacity to individually facilitate the preparation of gel-solubilized drugs. As MAG is an anionic surfactant with carboxyl groups, the addition of counterions may affect micelle formation and gelation. In this study, the solubilization and gelling properties of MAG were investigated following the addition of metal salts (NaCl and KCl). The addition of metal salts resulted in a decrease in the critical micelle concentration and an increase in gel hardness. Supersaturation of curcumin (CUR) was maintained by the addition of metal salts because of increased micelle number and viscosity. When the gel hardness was compared between formulations with and without CUR, a significant reduction in hardness was observed with the solubilization of CUR. The addition of KCl prevented the decrease in the hardness of gels containing CUR compared to the addition of NaCl. Put together, the addition of metal salts had a noteworthy impact on micelle and gel formation of MAG. In particular, the addition of KCl was more effective in the preparation of gel-solubilized CUR.
- Published
- 2024
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22. Improvement in Inhalation Properties of Theophylline and Levofloxacin by Co-Amorphization and Enhancement in Its Stability by Addition of Amino Acid as a Third Component.
- Author
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Ueda H, Hirakawa Y, Miyano T, Nakayama Y, Hatanaka Y, Uchiyama H, Tozuka Y, and Kadota K
- Subjects
- Levofloxacin, Administration, Inhalation, Leucine chemistry, Pharmaceutical Preparations, Drug Stability, Solubility, Calorimetry, Differential Scanning, Amino Acids chemistry, Theophylline
- Abstract
Co-amorphous systems are amorphous formulations stabilized by the miscible dispersion of small molecules. This study aimed to design a stable co-amorphous system for the co-delivery of two drugs to the lungs as an inhaled formulation. Theophylline (THE) and levofloxacin (LEV) were used as model drugs for treating lung infection with inflammation. Leucine (LEU) or tryptophan (TRP) was employed as the third component to improve the inhalation properties. The co-amorphous system containing THE and LEV in an equal molar ratio was successfully prepared via spray drying where reduction of the particle size and change to the spherical morphology were observed. The addition of LEU or TRP at a one-tenth molar ratio to THE-LEV did not affect the formation of the co-amorphous system, but only TRP acted as an antiplasticizer. The Fourier transform infrared spectroscopy spectra revealed intermolecular interactions between THE and LEV in the co-amorphous system that were retained after the addition of LEU or TRP. The co-amorphous THE-LEV system exhibited better in vitro aerodynamic performance than a physical mixture of these compounds and permitted the simultaneous delivery of both drugs in various stages. The co-amorphous THE-LEV system crystallized at 40 °C, and this crystallization was not prevented by LEU. However, THE-LEV-TRP maintained its amorphous state for 1 month. Thus, TRP can act as a third component to improve the physical stability of the co-amorphous THE-LEV system, while maintaining the enhanced aerodynamic properties.
- Published
- 2023
- Full Text
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23. The Enhanced Skin Permeation of Flavonoids Via the Application of a Coamorphous in a Microemulsion Formulation.
- Author
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Uchiyama H, Hanamoto Y, Hatanaka Y, Kadota K, and Tozuka Y
- Subjects
- Skin Absorption, Solubility, Water chemistry, Emulsions chemistry, Administration, Cutaneous, Flavonoids metabolism, Skin metabolism
- Abstract
Improving the permeability and solubility of poorly water-soluble compounds is a major difficulty in skin permeation. In this study, we investigated whether using a pharmaceutical technique such as applying coamorphous to a microemulsion enhances the skin permeation of polyphenolic compounds. The melt-quenching technique created the coamorphous system between naringenin (NRG) and hesperetin (HPT), two polyphenolic compounds with poor water solubility. By creating a supersaturated state, the aqueous solution of coamorphous NRG/HPT demonstrated improved NRG and HPT skin permeation. However, as both compounds precipitated, the supersaturation ratio decreased. In contrast to crystal compounds, incorporating coamorphous material into microemulsions enabled the preparation of microemulsions in a wider formulation range. Additionally, compared to microemulsions with crystal compounds and an aqueous suspension of coamorphous, microemulsions with coamorphous NRG/HPT increased skin permeation of both compounds by more than four times. These results suggested that interactions between NRG and HPT are maintained in the microemulsion and enhance both compounds' skin permeation. An approach for improving the skin permeation of poorly water-soluble chemicals would be to apply a coamorphous system to a microemulsion., Competing Interests: Declaration of Competing Interest The authors whose names are listed immediately below certify that they have NO affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript., (Copyright © 2023 American Pharmacists Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
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24. Usefulness of the two-devices-in-one-channel technique for difficult bile duct intubation in patients without periampullary diverticulum.
- Author
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Kaneko T, Sugimori K, Endo K, Nishimura M, Tozuka Y, Miwa H, and Maeda S
- Subjects
- Humans, Cholangiopancreatography, Endoscopic Retrograde methods, Bile Ducts, Intubation, Intratracheal, Ampulla of Vater, Diverticulum
- Abstract
Competing Interests: The authors declare that they have no conflict of interest.
- Published
- 2023
- Full Text
- View/download PDF
25. Sulfonium Salt Reagents for the Introduction of Deuterated Alkyl Groups in Drug Discovery.
- Author
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Ban K, Imai K, Oyama S, Tokunaga J, Ikeda Y, Uchiyama H, Kadota K, Tozuka Y, Akai S, and Sawama Y
- Subjects
- Deuterium chemistry, Sodium Chloride, Drug Discovery, Salts, Cytochrome P-450 Enzyme System
- Abstract
The pharmacokinetics of pharmaceutical drugs can be improved by replacing C-H bonds with the more stable C-D bonds at the α-position to heteroatoms, which is a typical metabolic site for cytochrome P450 enzymes. However, the application of deuterated synthons is limited. Herein, we established a novel concept for preparing deuterated reagents for the successful synthesis of complex drug skeletons with deuterium atoms at the α-position to heteroatoms. (d
n -Alkyl)diphenylsulfonium salts prepared from the corresponding nondeuterated forms using inexpensive and abundant D2 O as the deuterium source with a base, were used as electrophilic alkylating reagents. Additionally, these deuterated sulfonium salts were efficiently transformed into dn -alkyl halides and a dn -alkyl azide as coupling reagents and a dn -alkyl amine as a nucleophile. Furthermore, liver microsomal metabolism studies revealed deuterium kinetic isotope effects (KIE) in 7-(d2 -ethoxy)flavone. The present concept for the synthesis of deuterated reagents and the first demonstration of a KIE in a d2 -ethoxy group will contribute to drug discovery research based on deuterium chemistry., (© 2023 Wiley-VCH GmbH.)- Published
- 2023
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26. Unveiling the flavone-solubilizing effects of α-glucosyl rutin and hesperidin: probing structural differences through NMR and SAXS analyses.
- Author
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Kadota K, Kämäräinen T, Sakuma F, Ueda K, Higashi K, Moribe K, Uchiyama H, Minoura K, and Tozuka Y
- Subjects
- Rutin chemistry, X-Ray Diffraction, Protons, Scattering, Small Angle, Flavonoids, Magnetic Resonance Spectroscopy, Solubility, Hesperidin chemistry, Flavones
- Abstract
Flavonoids often exhibit broad bioactivity but low solubility and bioavailability, limiting their practical applications. The transglycosylated materials α-glucosyl rutin (Rutin-G) and α-glucosyl hesperidin (Hsp-G) are known to enhance the dissolution of hydrophobic compounds, such as flavonoids and other polyphenols. In this study, the effects of these materials on flavone solubilization were investigated by probing their interactions with flavone in aqueous solutions. Rutin-G and Hsp-G prepared via solvent evaporation and spray-drying methods were evaluated for their ability to dissolve flavones. Rutin-G had a stronger flavone-solubilizing effect than Hsp-G in both types of composite particles. The origin of this difference in behavior was elucidated by small-angle X-ray scattering (SAXS) and nuclear magnetic resonance analyses. The different self-association structures of Rutin-G and Hsp-G were supported by SAXS analysis, which proved that Rutin-G formed polydisperse aggregates, whereas Hsp-G formed core-shell micelles. The observation of nuclear Overhauser effects (NOEs) between flavone and α-glucosyl materials suggested the existence of intermolecular hydrophobic interactions. However, flavone interacted with different regions of Rutin-G and Hsp-G. In particular, NOE correlations were observed between the protons of flavone and the α-glucosyl protons of Rutin-G. The different molecular association states of Rutin-G or Hsp-G could be responsible for their different effects on the solubility of flavone. A better understanding of the mechanism of flavone solubility enhancement via association with α-glucosyl materials would permit the application of α-glucosyl materials to the solubilization of other hydrophobic compounds including polyphenols such as flavonoids.
- Published
- 2023
- Full Text
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27. Impact of multiple H/D replacements on the physicochemical properties of flurbiprofen.
- Author
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Uchiyama H, Ban K, Nozaki S, Ikeda Y, Ishimoto T, Fujioka H, Kamiya M, Amari R, Tsujino H, Arai M, Yamazoe S, Maekawa K, Kato T, Doi M, Kadota K, Tozuka Y, Tomita N, Sajiki H, Akai S, and Sawama Y
- Abstract
Although deuterium incorporation into pharmaceutical drugs is an attractive way to expand drug modalities, their physicochemical properties have not been sufficiently examined. This study focuses on examining the changes in physicochemical properties between flurbiprofen (FP) and flurbiprofen- d
8 (FP- d8 ), which was successfully prepared by direct and multiple H/D exchange reactions at the eight aromatic C-H bonds of FP. Although the effect of deuterium incorporation was not observed between the crystal structures of FP and FP- d8 , the melting point and heat of fusion of FP- d8 were lower than those of FP. Additionally, the solubility of FP- d8 increased by 2-fold compared to that of FP. Calculation of the interaction energy between FP/FP- d8 and water molecules using the multi-component density functional theory method resulted in increased solubility of FP- d8 . These novel and valuable findings regarding the changes in physicochemical properties triggered by deuterium incorporation can contribute to the further development of deuterated drugs., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2023
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28. Tailoring the Self-Assembly of Steviol Glycoside Nanocarriers with Steroidal Amphiphiles.
- Author
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Kämäräinen T, Kadota K, Arima-Osonoi H, Uchiyama H, and Tozuka Y
- Abstract
Bile salts are biosurfactants that can induce structure transformations in supramolecular nanoassemblies with conventional surfactants owing to their unique, planar amphiphilic character and the rigidity of their hydrophobic steroid skeleton. However, structural information about the association of bile salts and amphiphilic glycosides is lacking. In this work, we investigated the micelle structure of two anionic di- and trihydroxy bile salts [sodium deoxycholate (SDC) and sodium cholate (SC)] and a conventional anionic surfactant [sodium dodecyl sulfate (SDS)] in mixtures with a nonionic steviol glycoside [α-glucosyl stevia (Stevia-G)] and studied their potential as a nanocarrier system for two poorly water-soluble drugs (clotrimazole and ketoconazole). Decreased critical micelle concentrations determined from surface tension measurements demonstrate synergistic interactions between Stevia-G and SDS/SDC/SC in a decreasing order. Small-angle X-ray and neutron scattering, interpreted by a core-shell ellipsoid model, indicate that SDS and bile salts act differently on the mixed micelle structure. Compared with SDS/Stevia-G, bile salt/Stevia-G had a core-shell structure more similar to that of pure Stevia-G micelles. SDC and SDS had an increasing and decreasing influence, respectively, on the available molecular surface area in mixtures with Stevia-G on the micelle core but a similar influence on the micelle shell solvation number relative to that of their pure micellar structures. The number of bile salt hydroxyl groups was influential in determining the micelle stoichiometry: an increasing number of hydroxyl groups corresponded to decreasing bile salt aggregation numbers and a smaller hydrophobic micellar core. The core volume was the most important structural factor in explaining the drug solubilization capacity of the nanocarrier systems. Therefore, bile salt-steviol glycoside mixed micellar assemblies exhibit structure control mechanisms allowing the fine-tuning of their interior hydrophobic domains important for nanocarrier applications toward solubilization of poorly water-soluble drugs.
- Published
- 2023
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29. Drug-Facilitated Crystallization of Spray-Dried CD-MOFs with Tunable Morphology, Porosity, And Dissolution Profile.
- Author
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Kadota K, Tse JY, Fujita S, Suzuki N, Uchiyama H, Tozuka Y, and Tanaka S
- Subjects
- Crystallization, Pharmaceutical Preparations, Porosity, Solubility, Cyclodextrins chemistry, Metal-Organic Frameworks chemistry
- Abstract
Metal-organic frameworks (MOFs) with versatile functionalities have applications in environmental science, sensor separation, catalysis, and drug delivery. In particular, MOFs used in drug delivery should be biodegradable and easy to control. In this study, spray-dried cyclodextrin-based MOFs (CD-MOFs) with tunable crystallinity, porosity, and dissolution properties were fabricated. The spray-drying precursor properties, such as ethanol volume ratio, incubation time, and precursor concentration, were optimized for controlled crystallization. On the basis of the morphology, X-ray diffraction peak intensity, and specific surface areas of the spray-dried CD-MOF products, they were categorized as amorphous, partially crystalline, and highly crystalline. An active pharmaceutical ingredient ketoconazole (KCZ) was introduced into the precursor to prepare KCZ-containing CD-MOFs. The surface areas of these products were greater by 3-fold (292 m
2 /g) than that of the plain CD-MOF (94.1 m2 /g) prepared using the same parameters. The presence of KCZ in the hydrophobic cavity between the two γ-CD molecules was correlated to the CD-MOF crystal growth. Additionally, CD-MOF particles exhibited different dissolution behaviors on the basis of the position of KCZ in the MOF. These spray-dried CD-MOFs with tunable morphology, specific surface area, and dissolution could have potential applications in various fields.- Published
- 2023
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30. Designing a Novel Coamorphous Salt Formulation of Telmisartan with Amlodipine to Enhance Permeability and Oral Absorption.
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Hatanaka Y, Uchiyama H, Kaneko S, Ueda K, Higashi K, Moribe K, Furukawa S, Takase M, Yamanaka S, Kadota K, and Tozuka Y
- Subjects
- Animals, Humans, Telmisartan, Solubility, Permeability, Water, Amlodipine, Leukemia, Myeloid, Acute
- Abstract
Coamorphous formulation is a useful approach for enhancing the solubility of poorly water-soluble drugs via intermolecular interactions. In this study, a hydrogen-bonding-based coamorphous system was developed to improve drug solubility, but it barely changed the apparent permeability ( P
app ) of the drug. This study aimed to design a novel coamorphous salt using ionic interactions to improve drug permeability and absorption. Telmisartan (TMS), with an acidic group, was used to form a coamorphous salt with basic amlodipine (AML). Evaluation of the physicochemical properties confirmed the formation of a coamorphous salt via ionic interactions between the amine group of AML and the carboxyl group of TMS at a molar ratio of 1:1. The coamorphous salt of TMS/AML enhanced the partitioning of both drugs into octanol, indicating increased lipophilicity owing to the interaction between TMS and AML. The coamorphous salt dramatically enhanced TMS solubility (99.8 times that of untreated TMS) and decreased AML solubility owing to the interaction between TMS and AML. Although the coamorphous salt showed a decreased Papp in the permeation study in the presence of a thicker unstirred water layer (UWL) without stirring, Papp increased in the presence of a thinner UWL with stirring. The oral absorption of TMS from the coamorphous salt increased by up to 4.1 times compared to that of untreated TMS, whereas that of AML remained unchanged. Although the coamorphous salt with increased lipophilicity has a disadvantage in terms of diffusion through the UWL, the UWL is thin in human/animal bodies owing to the peristaltic action of the digestive tract. Dissociation of the coamorphous salt on the membrane surface could contribute to the partitioning of the neutral form of drugs to the membrane cells compared with untreated drugs. As a result, coamorphous salt formation has the advantage of improving the membrane permeation and oral absorption of TMS, owing to the enhanced solubility and supply of membrane-permeable free TMS on the surface of the membrane.- Published
- 2023
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31. Loop technique for guidewire manipulation during endoscopic ultrasound-guided hepaticogastrostomy.
- Author
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Miwa H, Sugimori K, Matsuoka Y, Endo K, Oishi R, Nishimura M, Tozuka Y, Kaneko T, Numata K, and Maeda S
- Abstract
Background and Aim: Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) is widely used in the management of biliary obstructions; however, literature on guidewire manipulation is lacking. This study aimed to assess the utility and optimal conditions of the loop technique for guidewire manipulation during EUS-HGS., Methods: Consecutive patients who underwent EUS-HGS between April 2015 and January 2022 were included in this study. Patient characteristics and procedural details were retrospectively analyzed. Guidewire manipulations were classified as conventional technique or loop technique, based on the shape of the guidewire tip., Results: A total of 52 patients (Median age: 73 years, 38 male and 14 female) underwent EUS-HGS. The median guidewire insertion time was 49 s and the median overall procedure time was 20.5 min. The initial guidewire direction was toward the peripheral side in 23 patients (44%). Technical success rate of the EUS-HGS was 100%. Twenty patients (38%) underwent the procedure using the loop technique and 32 (62%) with the conventional technique. In the logistic regression analysis, an angle between the bile duct and needle of >70° was independently associated with use of the loop technique (OR 9.84; 95% CI: 2.24-43.13; P <0.01)., Conclusion: This study revealed the utility of the loop technique in EUS-HGS. This technique is recommended if the bile duct is punctured at an angle >70°., (© 2023 The Authors. JGH Open published by Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)
- Published
- 2023
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32. FOLFOX regimen after failure of fluorouracil and leucovorin plus nanoliposomal-irinotecan therapy for advanced pancreatic cancer: a retrospective observational study.
- Author
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Kobayashi S, Tezuka S, Yamachika Y, Tsunoda S, Nagashima S, Tozuka Y, Fukushima T, Morimoto M, Ueno M, Furuse J, and Maeda S
- Subjects
- Humans, Irinotecan, Retrospective Studies, Leucovorin, Oxaliplatin therapeutic use, Anorexia chemically induced, Fluorouracil, Antineoplastic Combined Chemotherapy Protocols adverse effects, Pancreatic Neoplasms, Pancreatic Neoplasms pathology, Adenocarcinoma drug therapy
- Abstract
Background: Fluorouracil, leucovorin (5FU/LV), and nanoliposomal-irinotecan (nal-IRI) combination therapy has been established as the second-line treatment for advanced pancreatic ductal adenocarcinoma. Oxaliplatin with 5FU/LV (FOLFOX) is often used as a subsequent treatment, although its efficacy and safety are yet to be fully elucidated. We aimed to evaluate the efficacy and safety of FOLFOX as a third- or later-line treatment for patients with advanced pancreatic ductal adenocarcinoma., Methods: We conducted a single-centre, retrospective study that enrolled 43 patients who received FOLFOX after failure of gemcitabine-based regimen followed by 5FU/LV + nal-IRI therapy between October 2020 and January 2022. FOLFOX therapy consisted of oxaliplatin (85 mg/m
2 ), levo-leucovorin calcium (200 mg/m2 ) and 5-FU (2400 mg/m2 ) every 2 weeks per cycle. Overall survival, progression-free survival, objective response, and adverse events were evaluated., Results: At the median follow-up time of 3.9 months in all patients, the median overall survival and progression-free survival were 3.9 months (95% confidence interval [CI], 3.1-4.8) and 1.3 months (95% CI, 1.0-1.5), respectively. Response and disease control rates were 0 and 25.6%, respectively. The most common adverse event was anaemia in all grades followed by anorexia; the incidence of anorexia and grades 3 and 4 was 21 and 4.7%, respectively. Notably, grades 3-4 peripheral sensory neuropathy was not observed. Multivariable analysis revealed that a C-reactive protein (CRP) level of > 1.0 mg/dL was a poor prognostic factor for both progression-free survival and overall survival: hazard ratios were 2.037 (95% CI, 1.010-4.107; p = 0.047) and 2.471 (95% CI, 1.063-5.745; p = 0.036), respectively., Conclusion: FOLFOX as a subsequent treatment after failure of second-line treatment with 5FU/LV + nal-IRI is tolerable, although its efficacy is limited, particularly in patients with high CRP levels., (© 2023. The Author(s).)- Published
- 2023
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33. Tuning the Phytoglycogen Size and Aggregate Structure with Solvent Quality: Influence of Water-Ethanol Mixtures Revealed by X-ray and Light Scattering Techniques.
- Author
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Kämäräinen T, Kadota K, Tse JY, Uchiyama H, Oguchi T, Arima-Osonoi H, and Tozuka Y
- Subjects
- Solvents, X-Rays, Scattering, Small Angle, X-Ray Diffraction, Ethanol chemistry, Water chemistry
- Abstract
Phytoglycogen (PG) is a hyperbranched polysaccharide with promising properties for biomedical and pharmaceutical applications. Herein, we explore the size and structure of sweet corn PG nanoparticles and their aggregation in water-ethanol mixtures up to the ethanol mole fraction x
EtOH = 0.364 in dilute concentrations using small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS) measurements. Between 0 ≤ xEtOH ≤ 0.129, the conformation of PG contracts gradually decreasing up to ca. 80% in hydrodynamic volume, when measured shortly after ethanol addition. For equilibrated PG dispersions, SAXS suggests a lower PG volume decrease between 19 and 67% at the corresponding xEtOH range; however, the inflection point of the DLS volume contraction coincides with the onset of reduced colloidal stability observed with SAXS. Up to xEtOH = 0.201, the water-ethanol mixtures yield labile fractal and globular aggregates, as evidenced by their partial breakup under mild ultrasonic treatment, demonstrated by the decrease in their hydrodynamic size. Between 0.235 ≤ xEtOH ≤ 0.364, PG nanoparticles form larger, more cohesive globular aggregates that are less affected by ultrasonic shear forces.- Published
- 2023
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34. A review of transglycosylated compounds as food additives to enhance the solubility and oral absorption of hydrophobic compounds in nutraceuticals and pharmaceuticals.
- Author
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Uchiyama H, Kadota K, and Tozuka Y
- Subjects
- Solubility, Dietary Supplements, Pharmaceutical Preparations, Food Additives, Hesperidin chemistry
- Abstract
Transglycosylation has been used to modify the physicochemical properties of original compounds. As a result, transglycosylated compounds can form molecular aggregates in size ranges of a few nanometers in an aqueous medium when their concentrations exceed a specific level. Incorporating these hydrophobic compounds has been observed to enhance the solubility of hydrophobic compounds into aggregate structures. Thus, this review introduces four transglycosylated compounds as food additives that can enhance the solubility and oral absorption of hydrophobic compounds. Here, transglycosylated hesperidin, transglycosylated rutin, transglycosylated naringin, and transglycosylated stevia are the focus as representative substances. Significantly, we observed that amorphous formations containing hydrophobic compounds with transglycosylated compounds improved solubility and oral absorption compared to untreated hydrophobic compounds. Moreover, combining transglycosylated compounds with hydrophilic polymers or surfactants enhanced the solubilizing effects on hydrophobic compounds. Furthermore, the enhanced solubility of hydrophobic compounds improved their oral absorption. Transglycosylated compounds also influenced nanoparticle preparation of hydrophobic compounds as a dispersant. This study demonstrated the benefits of transglycosylated compounds in developing supplements and nutraceuticals of hydrophobic compounds with poor aqueous solubility.
- Published
- 2023
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35. Effect of Solubility Improvement via Formation of an Amorphous Composite of Indomethacin and Sulindac on Membrane Permeability.
- Author
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Hatanaka Y, Uchiyama H, Furukawa S, Takase M, Yamanaka S, Kadota K, and Tozuka Y
- Subjects
- 2-Hydroxypropyl-beta-cyclodextrin chemistry, Cell Membrane Permeability, Permeability, Solubility, Sodium Dodecyl Sulfate chemistry, Indomethacin, Sulindac
- Abstract
The importance of permeability as well as solubility of the drug has been recognized in improving the solubility of poorly water-soluble drugs. This study investigated the impact of amorphous composites of indomethacin (IMC) and sulindac (SLD) on the membrane permeability of drugs. The IMC/SLD (1/1) formulation prepared by dry grinding was amorphous with a single glass transition temperature. The Fourier transform IR spectra and Raman spectra revealed formation of hydrogen bonds between the OH group of IMC and the carbonyl group of SLD. These results suggest that an amorphous composite was formed between IMC and SLD through hydrogen bonding. The amount of dissolved IMC and SLD from the amorphous composite of IMC/SLD (1/1) was higher than that of the untreated IMC or SLD in the dissolution test. The permeated amounts and permeation rates of both drugs were enhanced by increasing the solubility of the amorphous composite. Conversely, the apparent membrane permeability coefficients (P
app ) were almost same for untreated drugs and amorphous composites. In the case of hydroxypropyl-β-cyclodextrin and sodium dodecyl sulfate, Papp of the drugs decreased with the addition of these compounds, although the drug solubility was enhanced by the solubilization effect. This study revealed that an amorphous composite formed through hydrogen bonding is an attractive pharmaceutical way to enhance the permeated amount and permeation rate without changing the Papp of both the drugs.- Published
- 2023
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36. Development of Bitter-Taste Masked Instant Jelly Formulations of Diphenhydramine Hydrochloride with Easy-to-Consume Granules.
- Author
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Fukada M, Kadota K, Nogami S, Uchiyama H, Shirakawa Y, and Tozuka Y
- Subjects
- Humans, Carrageenan pharmacology, Polymers, Spray Drying, Taste, Diphenhydramine chemistry
- Abstract
This study developed easy-to-consume bitter taste-masking granules for the preparation of instant jelly formulations. Composite granules containing diphenhydramine hydrochloride (DPH) and polymers were prepared via spray drying. The taste-masking effect on DPH was evaluated with acceptable linearity between DPH concentration and intensity of bitterness using an electronic tongue sensor. The results indicated that ι-carrageenan could provide the greatest suppression effect on the DPH bitterness among the polymers selected for preparing spray-dried particles (SDPs). The thixotropic index (TI) of ι-carrageenan was higher than that of the other polymers. In addition, two sulfate groups per two galactose molecules in one unit of ι-carrageenan improved interaction with DPH. Compared to κ-carrageenan, the electrostatic interaction with DPH may be stronger. Easy-to-consume SDPs with ι-carrageenan were used to prepare instant jelly formulations. The instant jelly formulation containing DPH with ι-carrageenan (3.0%) met the criteria for texture properties (hardness, adhesiveness, and cohesiveness) for patients with difficulty swallowing, as specified by the Consumer Affairs Agency. Furthermore, instant jelly enhanced the bitter taste suppression of DPH. Overall, using spray-dried granules with ι-carrageenan, this technique for preparing instant jelly formulations is simple and inhibits the bitter taste of drugs, contributing to the development of oral dosage forms suitable for patients of all ages.
- Published
- 2023
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37. Prognostic significance of sarcopenia as determined by bioelectrical impedance analysis in patients with advanced pancreatic cancer receiving gemcitabine plus nab-paclitaxel: A retrospective study.
- Author
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Tozuka Y, Ueno M, Kobayashi S, Morimoto M, Fukushima T, Sano Y, Kawano K, Hanaoka A, Tezuka S, Asama H, Moriya S, Morinaga S, Ohkawa S, and Maeda S
- Abstract
Sarcopenia often affects patients with various types of cancer, and has been reported to affect patient prognosis and therapeutic effects. However, to the best of our knowledge, there are no reports on the relationship between gemcitabine plus nab-paclitaxel combination therapy (GnP) and sarcopenia in patients with unresectable pancreatic cancer. The present study analyzed the relationship between overall survival (OS), progression-free survival (PFS), response rate, disease control rate, adverse events (AEs) and sarcopenia in patients with pancreatic cancer treated with GnP. A total of 121 consecutive patients with advanced pancreatic cancer who received GnP as first-line chemotherapy between January 2015 and December 2017 were retrospectively analyzed. GnP consisted of 1,000 mg/m
2 gemcitabine and 125 mg/m2 nab-paclitaxel, which were administered on days 1, 8 and 15 every 4 weeks. The skeletal muscle index (SMI) was calculated using bioimpedance analysis (BIA) as an index of sarcopenia prior to GnP. The patients were divided into sarcopenia (n=41) and non-sarcopenia (n=80) groups using cutoff values of 8.87 and 6.42 kg/m2 for male and female patients, respectively. The sarcopenia and non-sarcopenia groups had a median OS of 8.1 and 13.9 months, respectively [hazard ratio (HR) 0.79; 95% confidence interval (CI) 0.53-1.20], and a median PFS of 4.3 and 6.3 months, respectively (HR 0.63; 95% CI 0.42-0.95). The response and disease controls rate were not statistically different between the groups (20 vs. 32%, P=0.20; 81 vs. 80%, P=1.0). In addition, comparison of common grade 3 and 4 AEs between the two groups revealed no statistically significant differences. In conclusion, the results of the present study indicated that SMI obtained by BIA may be a predictor of treatment response and prognosis in patients with advanced pancreatic cancer who undergo GnP., Competing Interests: Dr Ueno and Dr Kobayashi reports grants and personal fees from Taiho Pharmaceutical. All the other authors declare that they have no competing interests., (Copyright: © Tozuka et al.)- Published
- 2022
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38. Modulating the Pore Architecture of Ice-Templated Dextran Microparticles Using Molecular Weight and Concentration.
- Author
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Kämäräinen T, Kadota K, Tse JY, Uchiyama H, Yamanaka S, and Tozuka Y
- Subjects
- Freeze Drying methods, Molecular Weight, Particle Size, Porosity, Dextrans, Ice
- Abstract
Spray freeze drying (SFD) is an ice templating method used to produce highly porous particles with complex pore architectures governed by ice nucleation and growth. SFD particles have been advanced as drug carrier systems, but the quantitative description of the morphology formation in the SFD process is still challenging. Here, the pore space dimensions of SFD particles prepared from aqueous dextran solutions of varying molecular weights (40-200 kDa) and concentrations (5-20%) are analyzed using scanning electron microscopy. Coexisting morphologies composed of cellular and dendritic motifs are obtained, which are attributed to variations in the ice growth mechanism determined by the SFD system and modulation of these mechanisms by given precursor solution properties leading to changes in their pore dimensions. Particles with low-aspect ratio cellular pores showing variation of around 0.5-1 μm in diameter with precursor composition but roughly constant with particle diameter are ascribed to a rapid growth regime with high nucleation site density. Image analysis suggests that the pore volume decreases with dextran solid content. Dendritic pores (≈2-20 μm in diameter) with often a central cellular region are identified with surface nucleation and growth followed by a slower growth regime, leading to the overall dendrite surface area scaling approximately linearly with the particle diameter. The dendrite lamellar spacing depends on the concentration according to an inverse power law but is not significantly influenced by molecular weight. Particles with highly elongated cellular pores without lamellar formation show intermediate pore dimensions between the above two limiting morphological types. Analysis of variance and post hoc tests indicate that dextran concentration is the most significant factor in affecting the pore dimensions. The SFD dextran particles herein described could find use in pulmonary drug delivery due to their high porosity and biocompatibility of the matrix material.
- Published
- 2022
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39. In silico evaluation of particle transport and deposition in the airways of individual patients with chronic obstructive pulmonary disease.
- Author
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Kadota K, Matsumoto K, Uchiyama H, Tobita S, Maeda M, Maki D, Kinehara Y, Tachibana I, Sosnowski TR, and Tozuka Y
- Subjects
- Administration, Inhalation, Aerosols, Humans, Lung, Particle Size, Dry Powder Inhalers, Pulmonary Disease, Chronic Obstructive drug therapy
- Abstract
Inhalation therapy can effectively treat chronic obstructive pulmonary disease (COPD), but the physical factors determining the appropriate aerosol delivery into the targeted airways remain unclear. The problem is nontrivial because pulmonary structures differ among individual patients with COPD and depend on the severity of the disease. In an in silico evaluation, the present study investigates the differences in particle transport and deposition in the airways of three patients with different degrees of COPD. Specific pulmonary airway models were reconstructed based on the computed tomography data of three patients with a different degree of COPD severity. The transport and deposition of inhaled particles in the airways were evaluated in a computational fluid dynamics simulation and a Lagrangian multiphase model. The sizes of the inhaled particles (1.0, 2.5, 5.5, 8.5, and 10.0 μm) were representative of drug particles delivered from inhalation devices, including dry powder inhalers (DPIs). The deposition behaviors of the inhaled particles strongly depended on the individual geometrical structure of the airways. The largest inhaled particles (10.0 μm) were most strongly affected by inertia and were deposited mostly in the oropharynx; consequently, they were rare in the bronchi. In contrast, the smallest inhaled particles (1.0 μm) were effectively delivered distally with the airflow. The spatial distributions and amounts of deposited particles in the airways obviously differed among the three COPD patients. Small particles are preferred as they can penetrate the inner lung regions. The results can assist the design and development of powder formulations and DPIs for patients with various severities of COPD., (Copyright © 2022 Elsevier B.V. All rights reserved.)
- Published
- 2022
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40. Design of a Stable Coamorphous System Using Lactose as an Antiplasticizing Agent for Diphenhydramine Hydrochloride with a Low Glass Transition Temperature.
- Author
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Ueda H, Hirakawa Y, Miyano T, Imono M, Tse JY, Uchiyama H, Tozuka Y, and Kadota K
- Subjects
- Calorimetry, Differential Scanning, Drug Stability, Solubility, Temperature, Transition Temperature, Diphenhydramine, Lactose
- Abstract
Coamorphous systems comprising small molecules are emerging as counterparts to polymeric solid dispersions. However, the glass transition temperatures ( T
g s) of coamorphous materials are relatively low because of the lack of polymeric carriers with higher Tg s. This study aimed to investigate the applicability of lactose (LAC) as an antiplasticizing coformer to a coamorphous system. Diphenhydramine hydrochloride (DPH) was selected as a model drug ( Tg = 16 °C). Differential scanning calorimetry showed a comelting point in addition to a decrease in the neat melting points depending on the composition of the physical mixtures, suggesting that the mixture of DPH-LAC was eutectic. The melting point of the eutectic mixture was calculated according to the Schröder-van Laar equation. The heat of fusion of the eutectic mixture was maximized at a 70:30 molar ratio of DPH to LAC; at this point, the melting peaks of the pure components disappeared. The heat flow profiles following the melting and cooling of DPH-LAC physical mixtures at the ratios from 10:90 to 90:10 showed a single Tg , suggesting the formation of a coamorphous system. Lactose showed a Tg of over 100 °C, and the Tg of DPH increased with the molar ratio of LAC; it was 84 °C at a 10:90 molar ratio of DPH to LAC. The Raman image indicated the formation of a homogeneous dispersion of DPH and LAC in the coamorphous system. Peak shifts in the infrared spectra indicated the presence of intermolecular interactions between the amino group of DPH and the hydroxyl group of LAC. Principal component analysis of the infrared spectra revealed a significant change at the 70:30 molar ratio of DPH to LAC, which was in agreement with the results of the thermal analysis. A stability test at 40 °C revealed rapid crystallization of the supercooled liquid DPH. The coamorphous samples containing 10-50% of LAC remained in an amorphous state for 21 days, and no crystallization was observed for the samples containing >60% of LAC for 28 days. The relatively lower Tg (less than 40 °C) of the coamorphous system containing 10-50% of LAC might have caused crystallization during storage. These findings indicate that LAC, which is a safe and widely used pharmaceutical excipient, can be applied to coamorphous systems as an antiplasticizing coformer.- Published
- 2022
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41. Computational approach to elucidate the formation and stabilization mechanism of amorphous formulation using molecular dynamics simulation and fragment molecular orbital calculation.
- Author
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Ma X, Higashi K, Fukuzawa K, Ueda K, Kadota K, Tozuka Y, Yonemochi E, and Moribe K
- Subjects
- Hydrogen Bonding, Phase Transition, Carbamazepine, Molecular Dynamics Simulation
- Abstract
α-Glycosyl rutin (Rutin-G) consists of a flavonol skeleton and sugar groups and is a promising additive for amorphous formulations. In our previous study, experimental approaches suggested an interaction between the model drug carbamazepine (CBZ) and flavonol skeleton of Rutin-G that stabilizes amorphous formulations. In the present study, the formation and stabilization mechanisms of CBZ/Rutin-G amorphous formulation were investigated using a computational approach. The CBZ/Rutin-G amorphous formulation was obtained via molecular dynamics (MD) simulation, which mimicked the melt-quenching method. Root mean square deviation analysis revealed that the translational motion of CBZ during the cooling process was suppressed by adding Rutin-G. Monitoring the atomic distance during the cooling process revealed that hydrogen bonds via carboxamide oxygen of CBZ with hydroxyl hydrogen of Rutin-G were preferentially formed with flavonol skeletons than sugar groups. The simulated amorphous formulation was then calculated using fragment molecular orbital (FMO) method. The quantitative evaluation of multiple interactions revealed that the hydrogen bond energy was higher in CBZ-sugar groups than in CBZ-flavonol skeleton, while the π-type of interaction energy was higher in CBZ-flavonol skeleton than in CBZ-sugar groups. The computational approach combining MD simulation and FMO calculation provides information on various interactions that are difficult to detect using experimental approaches, which helps understand the formation and stabilization mechanism of amorphous formulations., (Copyright © 2022. Published by Elsevier B.V.)
- Published
- 2022
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42. Structural changes in pH-responsive gelatin/hydroxypropyl methylcellulose phthalate blends aimed at drug-release systems.
- Author
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Nogami S, Kadota K, Uchiyama H, Arima-Osonoi H, Iwase H, Tominaga T, Yamada T, Takata SI, Shibayama M, and Tozuka Y
- Subjects
- Dynamic Light Scattering, Elastic Modulus, Hydrogen-Ion Concentration, Lisinopril pharmacology, Methylcellulose chemistry, Polymers chemistry, Rheology, Static Electricity, Drug Liberation, Gelatin chemistry, Methylcellulose analogs & derivatives
- Abstract
The present study aimed to investigate the thermal- and pH-dependent gelation behavior of gelatin/HPMCP blends using ultraviolet (UV) spectrophotometry, viscoelasticity, and dynamic light scattering (DLS). We found that the release of lisinopril from gelatin/HPMCP gels can be inhibited at low pH. UV spectrophotometric analysis showed that pH had a significant effect on the transparency of aqueous HPMCP systems and gelatin/HPMCP gels. The viscoelastic patterns of gelatin/HPMCP at pH 4.6 considerably differed from those of gelatin/HPMCP at pH 5.2 and 6.0. DLS measurements showed that HPMCP molecules in low concentrations underwent strong aggregation below pH 4.8. Such HPMCP aggregation induces a physical barrier in the matrix structures of the gelatin/HPMCP gels, which inhibits the drug release at pH 1.2. This hydrogel delivery system using polymer blends of gelatin/HPMCP can be used in oral gel formulations with pH-responsive properties., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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43. Porous particles and novel carrier particles with enhanced penetration for efficient pulmonary delivery of antitubercular drugs.
- Author
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Tse JY, Koike A, Kadota K, Uchiyama H, Fujimori K, and Tozuka Y
- Subjects
- A549 Cells, Administration, Inhalation, Aerosols, Animals, Antitubercular Agents chemistry, Antitubercular Agents toxicity, Cell Line, Tumor, Chemistry, Pharmaceutical methods, Dry Powder Inhalers, Excipients chemistry, Humans, Mice, Particle Size, Porosity, RAW 264.7 Cells, Rifampin chemistry, Rifampin toxicity, Tissue Distribution, Antitubercular Agents administration & dosage, Drug Delivery Systems, Glycogen chemistry, Rifampin administration & dosage
- Abstract
This study aimed to design dry powder inhaler formulations using a hydrophilic polymeric polysaccharide, phytoglycogen (PyG), as a multi-functional additive that increases the phagocytic activity of macrophage-like cells and enhances pulmonary delivery of drugs. The safety and usefulness of PyG were determined using in vitro cell-based studies. Dry powder inhaler formulations of an antitubercular drug, rifampicin, were fabricated by spray drying with PyG. The cytotoxicity, effects on phagocytosis, particle size, and morphology were evaluated. The aerosolization properties of the powder formulations were evaluated using an Andersen cascade impactor (ACI). Scanning electron microscope images of the particles on each ACI stage were captured to observe the deposition behavior. PyG showed no toxicity in A549, Calu-3, or RAW264.7 cell lines. At concentrations of 0.5 and 1 g/L, PyG facilitated the cellular uptake of latex beads and the expression of pro-inflammatory cytokine genes in RAW264.7 cells. Formulations with outstanding inhalation potential were produced. The fine particle fraction (aerodynamic size 2-7 µm) of the porous particle batch reached nearly 60%, whereas in the formulation containing wrinkled carrier particles, the extra-fine particle fraction (aerodynamic particle size < 2 μm) was 25.0% ± 1.7%. The deposition of porous and wrinkled particles on individual ACI stages was distinct. The inclusion of PyG dramatically improved the inhalation performance of porous and wrinkled powder formulations. These easily inhaled immunostimulatory carrier particles may advance the state of research by enhancing the therapeutic effect and alveolar delivery of antitubercular drugs., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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44. Novel clip device for prevention of bleeding after endoscopic papillectomy.
- Author
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Miwa H, Sugimori K, Tsuchiya H, Sugimori M, Nishimura M, Tozuka Y, Komiyama S, Sato T, Kaneko T, Numata K, and Maeda S
- Abstract
Objectives: Recently, a novel clip device, SureClip
® (Micro-Tech Co. Ltd., Nanjing, China), has been developed, which improved rotation and reopening performance. We aimed to assess the efficacy of the SureClip® in prophylactic closure of the mucosal break after endoscopic papillectomy (EP) for ampullary neoplasm., Methods: We retrospectively reviewed the medical records of 40 patients who underwent EP for ampullary neoplasms between October 2009 and March 2020. Prophylactic closure after resection was performed using the conventional clip between 2014 and 2018, and with the SureClip® after 2019. The baseline characteristics, techniques, outcomes, and complications of EP were analyzed., Results: The median age of the patients (25 males and 15 females) was 70 years. The en block resection rate was 82.5% and the curative resection rate was 80.0%. Histologically, 11 (27.5%) patients had malignancy. Prophylactic closure was performed in 29 (72.5%) patients (17 conventional clips, 12 SureClip® ). Complications occurred in 18 (45.0%) patients, including postprocedure bleeding in 9 (22.5%) patients. However, no postprocedure bleeding was observed in the patients who received prophylactic closure using the SureClip® ( p = 0.038). All other factors were not significantly correlated with postprocedure bleeding. The duration of hospital stay after EP was significantly shorter in patients treated with the SureClip® compared to those treated with a conventional clip or without clips ( p < 0.05)., Conclusions: In the present study, prophylactic clipping of the mucosal break using the SureClip® was effective in preventing bleeding after EP., Competing Interests: The authors declare that there is no conflict of interest., (© 2021 The Authors. DEN Open published by John Wiley & Sons Australia, Ltd on behalf of Japan Gastroenterological Endoscopy Society.)- Published
- 2021
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45. Multiple-line Chemotherapy for a Patient with Unresectable Mucinous Cystic Neoplasm of the Pancreas.
- Author
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Miwa H, Sugimori K, Ishii T, Funaoka A, Tsuchiya H, Suzuki Y, Sugimori M, Nishimura M, Tozuka Y, Komiyama S, Sato T, Kaneko T, Numata K, and Maeda S
- Subjects
- Aged, Albumins therapeutic use, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Female, Humans, Neoplasm Metastasis, Paclitaxel therapeutic use, Pancreas, Progression-Free Survival, Adenocarcinoma drug therapy, Pancreatic Neoplasms diagnostic imaging, Pancreatic Neoplasms drug therapy
- Abstract
A 74-year-old woman with a cyst in her pancreatic tail was referred to our hospital. Computed tomography confirmed a large cystic lesion with irregular wall thickening, abdominal lymph node swelling, and ascites. We diagnosed her with an unresectable mucinous cystic neoplasm, since ascites cytology revealed adenocarcinoma. The patient received chemotherapy up to the fifth line for 55.2 months. Gemcitabine plus nab-paclitaxel and modified FOLFIRINOX achieved a partial response with a progression-free survival time of 12.1 and 20.4 months, respectively. The overall survival time from the beginning of first-line chemotherapy was 69.4 months.
- Published
- 2021
- Full Text
- View/download PDF
46. Formulation and evaluation of bitter taste-masked orally disintegrating tablets of high memantine hydrochloride loaded granules coated with polymer via layering technique.
- Author
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Kadota K, Terada H, Fujimoto A, Nogami S, Uchiyama H, and Tozuka Y
- Subjects
- Administration, Oral, Drug Compounding, Humans, Polymers, Solubility, Tablets, Memantine, Taste
- Abstract
Orally disintegrating tablets (ODTs) improve patient adherence as they can easily disintegrate in the presence of small amount of saliva. However, the bitter taste of the active pharmaceutical ingredient in ODTs reduces patient compliance. The present study aimed to formulate bitter taste-masked ODTs containing high-dose of memantine hydrochloride (MTN) to achieve a balance between bitterness suppression and dissolution rate or disintegration time and mechanical strength. The high MTN-loaded granules were prepared using a fluidized bed granulator. Taste-masking granules coated with the selected polymer were prepared using the layering technique. Three ODTs, composed of granules coated with different polymers, were prepared. The ODT prepared using granules coated with enteric polymers showed the fastest collapse time (>20 s). Dissolution rates of ODTs composed of enteric polymers were reduced by 5 min compared with ODTs composed of non-coated or coated with water-insoluble polymer granules. X-ray computed tomography analysis revealed that low density distribution of ODTs with enteric polymer granules may result in faster disintegration time. Although ODT prepared using enteric polymers had the fastest collapse time, its change in membrane potential caused by adsorption (CPA), corresponding to aftertaste, was the lowest among formulations. This CPA value was lower than the bitterness threshold., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
47. Safe removal of lumen-apposing metal stent using argon plasma coagulation after EUS-guided cyst gastrostomy (with video).
- Author
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Miwa H, Sugimori K, Tsuchiya H, Nishimura M, Tozuka Y, Kaneko T, and Maeda S
- Abstract
Competing Interests: None
- Published
- 2021
- Full Text
- View/download PDF
48. Stabilization mechanism of amorphous carbamazepine by transglycosylated rutin, a non-polymeric amorphous additive with a high glass transition temperature.
- Author
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Aoki C, Ma X, Higashi K, Ishizuka Y, Ueda K, Kadota K, Fukuzawa K, Tozuka Y, Kawakami K, Yonemochi E, and Moribe K
- Subjects
- Calorimetry, Differential Scanning, Hypromellose Derivatives, Solubility, Transition Temperature, Carbamazepine, Rutin
- Abstract
α-Glycosyl rutin (Rutin-G), composed of a flavonol skeleton and sugar groups, is a promising non-polymeric additive for stabilizing amorphous drug formulations. In this study, the mechanism of the stabilization of the amorphous state of carbamazepine (CBZ) by Rutin-G was investigated. In comparison with hypromellose (HPMC), which is commonly used as a crystallization inhibitor for amorphous drugs, Rutin-G significantly stabilized amorphous CBZ. Moreover, the dissolution rate and the resultant supersaturation level of CBZ were significantly improved in the CBZ/Rutin-G spray-dried samples (SPDs) owing to the rapid dissolution property of Rutin-G. Differential scanning calorimetry measurement demonstrated a high glass transition temperature (T
g ) of 186.4°C corresponding to Rutin-G. The CBZ/Rutin-G SPDs with CBZ weight ratios up to 80% showed single glass transitions, indicating the homogeneity of CBZ and Rutin-G. A solid-state NMR experiment using13 C- and15 N-labeled CBZ demonstrated the interaction between the flavonol skeleton of Rutin-G and the amide group of CBZ. A1 H-13 C two-dimensional heteronuclear correlation NMR experiment and quantum mechanical calculations confirmed the presence of a possible hydrogen bond between the amino proton in CBZ and the carbonyl oxygen in the flavonol skeleton of Rutin-G. This specific hydrogen bond could contribute to the strong interaction between CBZ and Rutin-G, resulting in the high stability of amorphous CBZ in the CBZ/Rutin-G SPD. Hence, Rutin-G, a non-polymeric amorphous additive with high Tg , high miscibility with drugs, and rapid and pH-independent dissolution properties could be useful in the preparation of amorphous formulations., (Copyright © 2021 Elsevier B.V. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
49. Design of a pH-responsive oral gel formulation based on the matrix systems of gelatin/hydroxypropyl methylcellulose phthalate for controlled drug release.
- Author
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Nogami S, Uchiyama H, Kadota K, and Tozuka Y
- Subjects
- Drug Liberation, Gels, Hydrogen-Ion Concentration, Gelatin, Methylcellulose analogs & derivatives
- Abstract
Extensive efforts have been directed toward developing novel easily digested formulations with desirable controlled-release properties. The present study sought to develop pH-responsive oral gel formulations using combinations of gelatin and enteric polymers for controlled drug release under stimulated gastric conditions using acetaminophen and fluorescein isothiocyanate (FITC)-labeled dextran as model compounds. Hydroxypropyl methylcellulose phthalate (HPMCP) was identified as the optimal excipient for the pH-responsive drug release system because the release rates of acetaminophen in gelatin/HPMCP gels at pH 1.2 were exceedingly lower than those in other polymer-containing gels. Texture profile analysis of gelatin/HPMCP gels revealed the optimal content of excipients concerning ingestibility. FITC-labeled dextran of varying molecular weights was used to investigate the mechanism of compound release from the gelatin/HPMCP system under acidic conditions. The release properties practically depended on the molecular weight of FITC-dextran, and the compound release rate was proportional to the square root of time. The matrix structures of gelatin/HPMCP gels at low pH offer advantageous pH-responsive drug release profiles., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2021
- Full Text
- View/download PDF
50. Enhancement of the extra-fine particle fraction of levofloxacin embedded in excipient matrix formulations for dry powder inhaler using response surface methodology.
- Author
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Tse JY, Kadota K, Imakubo T, Uchiyama H, and Tozuka Y
- Subjects
- Administration, Inhalation, Aerosols, Excipients, Particle Size, Powders, Dry Powder Inhalers, Levofloxacin
- Abstract
Extra-fine particle fraction (eFPF, the fraction of particles with aerodynamic size <2 µm) is an essential metric to evaluate the deep lung delivery of dry powder inhalers (DPIs). The product of spray-drying has the potential to be applied in DPI formulations regarding its controllable size. This study performed an eFPF enhancement of levofloxacin DPI formulations by optimizing the spray-drying process parameters such as inlet temperature, feed flow rate, and gas flow rate, using a design space compiled from response surfaces. A polysaccharide, phytoglycogen, was used as an excipient matrix to prepare DPI formulations containing the antibiotic levofloxacin hydrate and the amino acid L-leucine. The aerodynamic-related properties and the percentage yield of spray-dried particles were evaluated as target outcomes. The influence of process variables on the product outcomes was also summarized. The most critical factor controlling inhalation properties was gas flow rate, owing to its significant contributions (p<0.05), which is coherent to most articles of engineering. A design space was plotted using response surfaces to optimize process parameters. The performance of the design space was evaluated. Most responses of the optimized runs were within the 95% prediction interval. The design space was adopted to successfully fabricate levofloxacin-containing deep lung delivery inhalable particles (eFPF >5%). The usefulness of the design space in another drug was also studied. The predicted design space may support future studies that aim to prepare composite particles with fair alveolar inhalation performance for DPI formulations using a hydrophilic macromolecular polysaccharide excipient matrix and leucine., (Copyright © 2020. Published by Elsevier B.V.)
- Published
- 2021
- Full Text
- View/download PDF
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