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The purpose of this study is to produce nanostructured lipid carrier (NLC) that can solubilize poorly water-soluble velutin and verify an improved tyrosinase synthesis inhibition. A solubility test for velutin was conducted. Cetyl palmitate and caprylic/capric triglyceride were selected as solubilizer. The lipid matrix was produced using the ultrasound dispersion method. The morphology and size distribution of the produced NLC was analyzed through scanning electron microscopy (SEM) and dynamic light scattering (DLS), and the release and tyrosinase inhibition of velutin was evaluated through the Franz diffusion cell method and tyrosinase inhibition assay. Lipid matrix nanoparticles showed an average size of approximately 250 nm and polydispersity of 0.2, and it was confirmed that the velutin incorporated within nanoparticles sustained release at a constant rate over 36 hours. Due to extremely low aqueous solubility, the tyrosinase synthesis inhibition of velutin suspension was 0%, and the value of velutin incorporated within the NLC formulation was greatly improved 56.5% (40 μg/mL). As a result, it was verified that lipid-based NLC nanoparticles are an efficient formulation for the topical delivery of poorly water-soluble flavonoids such as velutin.

The purpose of this study is to investigate the surface activity of starch nanocrystals (SNC), material derived from starch, and confirm their usefulness as a surfactant. In order to evaluate the surface activity, the surface tension change of suspended SNC solution via the Wilhelmy plate method was measured and the values were compared with various synthetic surfactants. The effect of SNC as emulsifier was evaluated on emulsion formation and physical stability. The surface tension of the SNC-dispersed solution was decreased while its concentration was increased. When the 5.0% (w/v) of SNC was added, the surface tension was decreased from 70.3 to 49.5 mN/m. It was confirmed that the physical stability of the emulsion prepared by adding the SNC was improved compared to that of surface inactivity material (PEG 400). The phase separation was observed within 1 hour after preparation of the emulsion containing PEG 400, but the emulsion containing SNC was stable for 5 hours or more. To summarize this study, SNC, a natural-derived and non-toxic material, exhibits sufficient surface activity, thereby confirming the possibility of being applied to the food and pharmaceutical industry.

Self-microemulsifying drug delivery systems represent a stable formulation for enhancing the solubility and absorption efficacy of poorly soluble drugs. In this study, a self-microemulsifying drug delivery system (SMEDDS) was designed and applied for oral administration of poorly water-soluble pazopanib, a Biopharmaceutical Classification Class II anticancer drug. The solubility of pazopanib was first evaluated using various oils, surfactants, and co-surfactants. Pseudoternary phase diagrams were plotted to identify the selfemulsifying region and the phase behavior of optimized vehicle selected after screening of oils, surfactants, and co-surfactants. The SMEDDS comprising Capmul MCM NF, Tween 80, and PEG 400 was fabricated for incorporating pazopanib. It exhibited spherical droplets with size of 86.9 ± 0.8 nm and zeta potential value of –14.7 ± 0.1 mV. In vitro dissolution profiles of the SMEDDS were 2.40-fold (pH 4.0) and 6.45-fold (pH 6.8) higher than that of pazopanib powder. In particular, pazopanib-SMEDDS showed pH-independent dissolution profiles. In vivo pharmacokinetic parameters of the SMEDDS revealed enhanced bioavailability of pazopanib, which was 3.32-fold higher than that of pazopanib powder when administered orally. Taken together, the SMEDDS is effective as an oral delivery vehicle for pazopanib. In addition, our findings demonstrate that self-microemulsifying drug delivery systems could be a potential tool for improving bioavailability of other poorly water-soluble drugs.

Sorafenib, a potent anticancer drug, has low absorption in the gastrointestinal tract due to its poor aqueous solubility. The main purpose of this investigation was to design sorafenib nanoparticle using a newly developed technique, nanoparticulation using fat and supercritical fluid (NUFS™) to improve the absorption of sorafenib. The quality by design (QbD) tool was adopted to define the optimal formulation variables: hydroxypropyl methyl cellulose (HPMC), polyvinyl pyrrolidone K30 (PVP), and poloxamer. The studied response variables were particle size of nanoparticle, dissolution (5, 60, and 180 min), drug concentration time profile of nanoparticle formulations, and maximum drug concentration. The result of particle size revealed that an increase in concentration of poloxamer and HPMC decreased the particle size of nanoparticles (p 0.05). Likewise, the concentration of drug release at different time point (5, 60, and 180 min) showed HPMC and poloxamer had positive effects on drug dissolution while PVP had negative effects on it. The design space was built in accordance with the particle size of nanoparticle (target 500 nm) and dissolution of sorafenib (target 7 µm/mL), following failure probability analysis using Monte Carlo simulations. In vivo pharmacokinetics studies in beagle dogs demonstrated that optimized formulation of sorafenib (F3 and F4 tablets) exhibited higher blood drug profiles indicating better absorption compared to the reference tablet (Nexavar

The aim of this study is to develop nanosuspension for improved dissolution of poorly water-soluble celecoxib. We first prepared coarse suspension of celecoxib with Tween 80 and hydroxypropyl methylcellulose as stabilizers, and then fabricated nanosuspension using the bead milling technique. Depending on milling time, the physical properties of nanosuspension were evaluated by photon correlation spectroscopy (e.g., particle size and distribution) and scanning electron microscopy (SEM) (e.g., morphology). As results, the mean size of crystalline celecoxib particles was highly reduced (368.1±14.5 nm) as milling process proceeded comparing to celecoxib powder (6.5±1.0 μm). Morphology of milled celecoxib particles has changed considerably from bar-shape or plate-shape to needle-shape due to a high energy caused by milling. In the dissolution test, the celecoxib nanosuspension showed an improved dissolution profile at pH 1.2 compared to celecoxib powder (less than 1%). In contrast, 53.4% of celecoxib in nanosuspension was dissolved up to 30 minutes, demonstrating improved dissolution of celecoxib. Taken together, bead-milled nanosuspension could be an effective strategy that can improve the dissolution and bioavailability.

Sorafenib, an oral multikinase inhibitor, exhibits a highly variable absorption profile due to enterohepatic reabsorption and poor solubility. SYO-1644 improved the solubility of sorafenib by nanoparticulation technology leading to enhanced bioavailability. To evaluate the pharmacokinetically equivalent dose of SYO-1644 to the reference Nexavar® 200 mg, a randomized, open-label, replicated two-period study was conducted in healthy volunteers. A total of 32 subjects orally received a single dose of the following assigned treatment under a fasted state in the first period and repeated once more in the second period with a two-week washout: SYO-1644 100, 150 and 200 mg and Nexavar® 200 mg. Pharmacokinetic (PK) samples were collected up to 168 h post-dose. The PK profile was evaluated by both non-compartmental analysis and population PK method. With the final model, 2 × 2 crossover trial scenarios with Nexavar® 200 mg and each dose of SYO-1644 ranging from 100 to 150 mg were repeated 500 times by Monte Carlo simulation, and the proportion of bioequivalence achievement was assessed. Transit absorption compartments, followed by a one-compartment model with first-order elimination and enterohepatic reabsorption components were selected as the final model. The simulation results demonstrated that the SYO-1644 dose between 120 and 125 mg could yielded the highest proportion of bioequivalence.

The aim of this study was to improve the skin accumulation of hydroxycitric acid by using ethosomes with nanosize. We fabricated nanosized ethosome for the topical delivery of hydrophilic hydroxycitric acid and evaluated their physical properties and furthermore cytotoxicity. As results, in cell-based experiments, the use of ethosomes encapsulating hydroxycitric acid extract reduced the lipid droplet deposition in differentiated adipocytes, which was visualized by Oil Red O staining assay and also quantitatively measured by a triglyceride assay. The observed reduction in lipid droplet deposition occurred in a hydroxycitric acid extract concentration-dependent manner. In addition, the high accumulation of hydroxycitric acid in murine skin (66.28%) was observed following treatment with hydroxycitric acid extract-loaded ethosomes compared with treatment with hydroxycitric acid alone (1.19%) without ethosome as a nanocarrier. Based on these results, our findings showed that nanosized ethosomes improved the topical delivery of hydroxycitric acid and thus reduced lipid droplet deposition in adipocytes.

The purpose of this study is to identify the effects of a stabilizer and matrix former in the development of a celecoxib dried nanosuspension (DNS) for high dissolution rate and drug loading. Tween 80 and Hydroxypropyl Methylcellulose (HPMC) were used as stabilizers in the bead-milling process and dextrin was used as the matrix former in the spray-drying. Various nanosuspensions (NS) were prepared by varying the ratio of HPMC and dextrin, and the physicochemical properties of each formulation were evaluated for particle size, morphology, drug loading, crystallinity, redispersibility, physical stability and dissolution rate. HPMC efficiently stabilized the NS system and reduced the particle size of NS. The mean particle size of the NS with 0.5% HPMC (w/v) was the smallest (248 nm) of all formulations. Dextrin has been shown to inhibit the increase of particle size efficiently, which is known to occur frequently when NS is being solidified. As the dextrin increased in DNS, the dissolution rates of reconstituted NS were significantly improved. However, it was confirmed that more than the necessary amount of dextrin in DNS reduced the dissolution and drug loading. The dissolution of celecoxib in DNS prepared at the ratio (drug:dextrin, 1:2.5) was almost the highest. The dissolution of optimal formulation was 95.8% at 120 min, which was 2.0-fold higher than that of NS dried without dextrin. In conclusion, these results suggest that the formulation based on Tween 80, HPMC and dextrin may be an effective option for DNS to enhance its in vitro dissolution and in vivo oral absorption.

The purpose of this study was to develop and evaluate a dry elixir (DE) system for enhancing the dissolution rate and oral bioavailability of celecoxib. DE system has been used for improving solubility, oral bioavailability of poorly water-soluble drugs. The encapsulated drugs or solubilized drugs in the matrix are rapidly dissolved due to the co-solvent effect, resting in both an enhanced dissolution and bioavailability. DEs containing celecoxib were prepared by spray-drying method and characterized by morphology, drug/ethanol content, drug crystallinity, dissolution rate and oral bioavailability. The ethanol content and drug content in DE system could be easily altered by controlling the spraydrying conditions. The dissolution profile of celecoxib from DE proved to be much higher than that of celecoxib powder due to the nano-structured matrix, amorphous state and encapsulated ethanol. The bioavailability of celecoxib from DEs was compared with celecoxib powder alone and commercial product (Celebrex®) in rats. In particular, blood concentrations of celecoxib form DE formulation were much greater than those of native celecoxib and market product. The data demonstrate that the DE system could provide an useful solid dosage form to enhance the solubility, dissolution rate and oral bioavailability of celecoxib.

Mistletoes, hemiparasites, contain many components with various biological activities and have been used in cosmetics industry. Loranthacease (1,000 species) and Viscaceae (550 species) have the most dominant species in mistletoes (nearly 1,600 species). It can be expected that the biological activities vary from species to species; therefore, we have tested

The purpose of this study is to develop a solid dispersion system with improved dissolution, absorption, and patient compliance of poorly water-soluble celecoxib (CXB). Instead of sodium lauryl sulfate (SLS), an anionic surfactant used in the marketed product (Celebrex&reg, ), solubilization was performed using non-ionic surfactants with low toxicity. Cremophor RH40 (Cre-RH) was selected as the optimal solubilizer. Granules and tablets containing CXB and Cre-RH were prepared via fluid-bed and tableting processes, respectively. The morphology, crystallinity, flowability, dissolution, and pharmacokinetics for CXB-solid dispersion granules (SDGs) and the hardness and friability for CXB-solid dispersion tablets (SDTs) were evaluated. The solubility of CXB was found to be increased by about 717-fold when using Cre-RH. The dissolution of granules containing Cre-RH was found to be increased greatly compared with CXB API and Celebrex&reg, (66.9% versus 2.3% and 37.2% at 120 min). The improvement of the dissolution was confirmed to be the same as that of granules in tablets. The CXB formulation resulted in 4.6- and 4.9-fold higher AUCinf and Cmax of CXB compared with those of an oral dose of CXB powder in rats. In short, these data suggest that the solid dispersion based on Cre-RH&mdash, a non-toxic solubilizer, non-ionic surfactant&mdash, may be an effective formulation for CXB to enhance its oral bioavailability and safety.

The aim of this study is to develop an effective delivery system (silica microparticles) encapsulating volatile essential oil (EO) by multiple emulsification process and sol-gel method. Depending on critical materials (Pluronic P123 and HPC) and process parameter (drying temperature), silica microparticles were prepared and evaluated. As results, the amount of EO inside microparticles increased in polymer-dependent manners. On the other hand, the amount of EO was reduced as drying temperature increased. Based on these data, the condition fabricating silica microparticles was optimized: drying temperature (25 °C), Pluronic P123 (1.2%) and HPC (1.2%). The size and morphology of microparticles were observed by scanning electron microscopy. Also, the loadings and release profiles of EO in these particles were quantitatively analyzed by HPLC. Optimized silica microparticles showed the high encapsulation efficiency (32.7%) and sustained-release profiles of EO for 3 days. Taken together, silica microparticles are effective carrier for encapsulating volatile materials and providing sustained-release.

This study aims at developing and evaluating reconstitutable dry suspension (RDS) improved for dissolution rate, oral absorption, and convenience of use of poorly water-soluble celecoxib (CXB). Micro-sized CXB particle was used to manufacture nanosuspension by using bead milling and then RDS was made by spray-drying the nanosuspension with effective resuspension agent, dextrin. The redispersibility, morphology, particle size, crystallinity, stability, dissolution, and pharmacokinetic profile of the RDS were evaluated. RDS was effectively reconstituted into nanoparticles in 775.8 &plusmn, 11.6 nm. It was confirmed that CXB particles are reduced into needle-shape ones in size after the bead-milling process, and the description of CXB was the same in the reconstituted suspension. Through the CXB crystallinity study using differential scanning calorimetry (DSC) and XRD analysis, it was identified that CXB has the CXB active pharmaceutical ingredient (API)&rsquo, s original crystallinity after the bead milling and spray-drying process. In vitro dissolution of RDS was higher than that of CXB powder (93% versus 28% dissolution at 30 min). Furthermore, RDS formulation resulted in 5.7 and 6.3-fold higher area under the curve (AUC&infin, ) and peak concentration (Cmax) of CXB compared to after oral administration of CXB powder in rats. Collectively, our results suggest that the RDS may be a potential oral dosage formulation for CXB to improve its bioavailability and patient compliance.

Nanostructured supramolecular assemblies with hydrophobic cavities are used for improving the solubility, bioavailability, and stability of poorly water soluble drugs. In particular, host-guest inclusion using 2-hydroxypropyl-beta-cyclodextrin (HP-β-CD) is a typical approach in the pharmaceutical field. In this study, celecoxib (CXB), a cyclooxygenase-2 selective nonsteroidal anti-inflammatory drug (NSAID), was used as the model drug (guest material) and effectively incorporated into HP-β-CD (host material). After forming a complete complex of HP-β-CD and CXB, 1-adamantylamine (ADA) was used to allow CXB to be released from the HP-β-CD in a concentration-dependent manner. This was revealed from Fourier-transform infrared spectroscopy and drug dissolution studies. Notably, the use of ADA, which is a high-affinity guest molecule, with cyclodextrin accelerated the removal of CXB from the host material through the exchange of guest molecules. Taken together, the host-guest based approach using a second guest molecule is useful for regulating on-demand drug release and could therefore be a potential tool for biomedical applications.

In this work, hydrolytic reaction conditions of various temperatures (300–370 °C) and times (0–30 min) at a constant pressure of 20 MPa were applied to the thermal decomposition of three kinds of fatty acids (FAs), stearic acid, oleic acid, and linoleic acid, in subcritical water. The degradation characteristics were investigated from the derived data, and the thermal stability of FAs in subcritical water was estimated. The primary reactions we observed were isomerization and pyrolysis of FAs. The main pathway of degradation was deduced by analyzing the contents of pyrolyzed products. We found that more saturated FAs have greater thermal stability in subcritical water. All FAs remained stable at 300 °C or below. Based on these results, we recommend that hydrolysis of vegetable oils and fats using subcritical water should be carried out below 300 °C (at 20 MPa) and for less than 30 min to obtain high-yield FA production.

Two types of temperature-sensitive biodegradable three-arm and four-arm star-shaped poly(DL-lactic acid-co-glycolic acid-b-ethylene glycol) (3-arm and 4-arm PLGA–PEG) were successfully synthesized via the coupling reaction of 3-arm and 4-arm PLGA and α-monocarboxyl-ω-monomethoxypoly(ethylene glycol) (CMPEG). In dilute aqueous solutions, star PLGA–PEGs showed the temperature- and concentration-dependent formation and aggregation of micelles over specific concentration and specific temperature. With increasing the molecular weight and the relative hydrophobicity of hydrophobic PLGA block, critical micelle temperature (CMT) decreased. Aqueous solution of 4-arm PLGA–PEG started to form micelles at lower temperature and showed sharper temperature-dependent growth in micelle size. These results are due to the enhanced hydrophobicity of PLGA block. On the other hand, at high concentration, two types of 3-arm and 4-arm PLGA–PEG showed sol–gel–sol transition behavior as the temperature was increased. The 3-arm and 4-arm PLGA–PEG showed sol–gel transition at higher polymer concentrations (above 24 wt %) than the PEG–PLGA–PEG triblock copolymer. As the molecular weight and the relative hydrophobicity of PLGA block increased, the critical gel concentration (CGC) decreased. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 888–899, 2006

Nontoxic and biodegradable star-shaped poly(l-lactide-b-ethylene oxide) (star PLLA−PEO) block copolymers were synthesized by the coupling reaction of two reactive precursors, a hydroxy-terminated 3...

Novel pH-sensitive polymers were synthesized by copolymerizing a monomer derivatized from 4-amino-N-[4,6-dimethyl-2-pyrimidinyl]benzene sulfonamide with N,N-dimethylacrylamide. The linear copolymers showed pH-sensitive solubility, while chemically crosslinked hydrogels exhibit a relatively sharp transition in swelling around physiological pH. These changes were found to be reversible. By varying the type of sulfonamide and the copolymer composition, a new class of pH-sensitive polymers with a broad range of transition pH can be synthesized.