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Objective: This study aimed to develop a stable and scalable enteric film-coated tablet for the gastric irritant dexibuprofen., Methods: Utilizing direct compression with super-disintegration (crospovidone), the optimal core batches were coated with Opadry white seal coat and enterically coated with Eudragit ® L100 with pigment (Talc), demonstrating a 12% weight increase; release and integrity were assessed using specific pH buffers and SEM, with stability testing confirming a six-month shelf life at 40 °C and 75% RH., Results: The optimized formulation achieved 99.87% release in phosphate buffer within 60 min, maintained integrity for 120 min in acidic conditions, and exhibited superior bioavailability compared to Innovifen with relative bioavailability ≈of 121% and elevated C max (18.35 µg/ml compared to 11.1 µg/ml)., Conclusion: These results highlight the potential of this formulation to enhance patient safety and efficacy through delayed enteric technology and fast intestinal release.

The aim of this study was to prepare nintedanib nanocrystals (BIBF-NCs) to lower the solubility of the drug in the stomach, maintain the supersaturation of the drug in the intestine, and improve the oral absorption of nintedanib (BIBF). In this study, BIBF-NCs were prepared by acid solubilization and alkaline precipitation following nano granding method, with a particle size of 290.80 nm and a zeta potential of -49.13 mV. Subsequently, Nintedanib enteric-coated nanocrystals (BIBF-NCs@L100) were obtained by coating with Eudragit L100. The microscopic morphology, crystalline characteristics, stability, and in vitro dissolution of BIBF-NCs and BIBF-NCs@L100 were also studied. In addition, the in vivo pharmacokinetic behaviors of Samples prepared according to the prescription process of commercially available soft capsules (soft capsules), BIBF-NCs, and BIBF-NCs@L100 were further investigated. The results showed that the oral bioavailability of BIBF-NCs and BIBF-NCs@L100 were increased by 1.43 and 2.58 times, compared with that of the soft capsules. BIBF-NCs@L100 effectively reduced the release of BIBF in the formulation in the stomach, allowing more drug to reach the intestine in the form of nanocrystals, maintaining the supersaturation in the intestine, thereby improving the oral bioavailability of the drug., 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.)

Size expansion can effectively improve tumor accumulation of nanocarriers where precise control is required. A dual-responsive nanocarrier stimulated by both endogenous pH and exogenous heat stimuli can change its size. Herein, a nanoparticle composed of poly( N , N -diethyl acrylamide) (PDEAA) and poly(2-(diisopropylamino) ethyl methacrylate) (PDPA) is developed. The antitumor drug celastrol (CLT) and the photosensitizer indocyanine green (ICG) are then loaded in it to form CIPP. ICG generates heat under near-infrared (NIR) stimulation to kill tumor cells and enhance CIPP penetration. Meanwhile, CIPP expands in response to hyperthermia and acid tumor microenvironments, preventing itself from returning to the blood flow, thus accumulating in tumor sites. Ultimately, the acidic lysosomal environment in tumor cells disintegrates CIPP to release CLT, directly inducing immunogenic cell death and sensitizing tumor cells for hyperthermia by disrupting the interaction of heat shock protein 90 and P50 cdc37 . Most of the tumors in B16F10-bearing mice are eradicated after single laser irradiation. The dual-responsive CIPP with multiple functions and simple design displays a synergistic antitumor effect. This study provides a basis for developing size-expandable stimulus-responsive drug delivery systems against tumors.

Objective: The purpose of the present study was firstly to identify the effectiveness of Eudragit® polymers (Eudragit ® RL, RS, L100-55, L100, S100 and E100) in inhibition of celecoxib precipitation from buffer solutions (pH = 6.8). Furthermore, the influence of Eudragit ® polymers on non-sink dissolution behavior of celecoxib from solid dispersions was investigated., Methods: Solid dispersions were prepared by the rotary evaporation method. In vitro dissolution studies, FT-IR and differential scanning calorimetry were employed to characterize the formulations., Results: The results revealed that Eudragit ® E100, L100 and S100 inhibited precipitation of celecoxib efficiently. It is understood that crystallization during the dissolution of solid dispersions could happen through crystallization from solid matrix following contact with the dissolution medium or from the supersaturated solution produced following dissolution. The supersaturated drug concentrations attained from the dissolution of Eudragit ® -celecoxib solid dispersions were almost similar, suggesting that crystallization from solid matrix did not occur readily. However, only solid dispersions containing efficient crystallization inhibitor polymers were able to maintain the supersaturated solution up to the end of the dissolution run., Conclusion: Results revealed that the principal mechanism of attaining supersaturated solution of celecoxib from solid dispersions was related to crystallization inhibition from solution not from solid matrix.

The oral bioavailability of curcumin is limited, attributed to its low solubility or dissolution and poor absorption. Herein, the study describes formulation of curcumin-loaded mixed micelles of Gelucire® 48/16 and TPGS for its dissolution rate enhancement. Curcumin was dispersed in these molten lipidic surfactants which was then adsorbed on carrier and formulated as pellets by extrusion spheronization. Critical micelle concentration (CMC) of binary mixture of Gelucire® 48/16 and TPGS was lower than their individual CMC demonstrating the synergistic behavior of mixture. Thermodynamic parameters like partition coefficient and Gibbs free energy of solubilization indicated that mixed micelles were more efficient than micelles of its individual components in curcumin solubilization. Dynamic light scattering (DLS) suggested slight increase in micellar size of mixed micelles than its components suggesting curcumin loading in mixed micelles. Fourier transform infrared spectroscopy (FTIR) revealed that phenolic hydroxyl group interacts with lipids which contribute to its enhanced solubility. Furthermore, the differential scanning calorimetry (DSC) and X-ray diffraction (XRD) study indicated the conversion of crystalline curcumin into amorphous form. In the pellet formulation, Gelucire® 48/16 acted as a binder and eliminated the requirement of additional binder. Microcrystalline cellulose (MCC) forms wet mass and retards the release of curcumin from pellets. Increase in concentration of water-soluble diluent increased drug release. The optimized formulation released more than 90% drug and maintains supersaturation level of curcumin for 2 h. Thus, mixed micellar system was effective delivery system for curcumin while pellet formulation is an interesting formulation strategy consisting semi-solid lipids.

This study aimed to develop a ternary nanocomposite system of organoclay, glycol-chitosan, and Eudragit ® S100 as an effective colon targeted drug delivery carrier to enhance the oral absorption of insulin. A nanocomplex of insulin and aminoclay was prepared via spontaneous co-assembly, which was then coated with glycol-chitosan and Eudragit S ® 100 (EGAC-Ins). The double coated nanocomplex, EGAC-Ins demonstrated a high entrapment efficiency of greater than 90% and a pH-dependent drug release. The conformational stability of insulin entrapped in EGAC-Ins was effectively maintained in the presence of proteolytic enzymes. When compared to a free insulin solution, EGAC-Ins enhanced drug permeability by approximately sevenfold in Caco-2 cells and enhanced colonic drug absorption in rats. Accordingly, oral EGAC-Ins significantly reduced blood glucose levels in diabetic rats while the hypoglycemic effect of an oral insulin solution was negligible. In conclusion, EGAC-Ins should be a promising colonic delivery system for improving the oral absorption of insulin.

Background/aims: Inflammatory bowel disease is a chronic or remitting/relapsing intestinal inflammation, which comprises Crohn's disease and ulcerative colitis (UC). Severe UC is a life-threatening condition that requires corticosteroids (CS) as a first-line rescue therapy. Some patients are refractory to CS and may require alternative immunosuppressive therapy. Oral tacrolimus (FK506), an immunosuppressive agent, has been reported to be effective in the management of severe refractory UC, but it can cause serious adverse effects. This work aims to study the effect of tacrolimus delivered by a colon-targeted delivery system (CTDS) in a dextran sulfate sodium (DSS)-induced animal model of colitis., Materials and Methods: We developed and evaluated an oral CTDS of tacrolimus (FK506) loaded pH-dependent polymeric microspheres, composed of Eudragit® S100 as a pH-sensitive polymer using the oil-in-water emulsion method. The physicochemical properties and drug release profiles of these microparticles in gastrointestinal tract (GIT) conditions were examined. A DSS-induced colitis rat model was used to evaluate the potential remedial and in vivo distribution of microspheres., Results: The pH-microspheres prevented a burst drug release in acidic pH conditions and showed sustained release at a colonic pH. The in vivo distribution study in the rat GIT demonstrated that pH-microspheres were successfully delivered to the inflamed colon. Moreover, it also demonstrated a significant decrease of disease activity and expression of proinflammatory cytokines, such as tumor necrosis factor α, interleukin-1β (IL-1β), and IL-6, and minimized the histological and morphometric changes., Conclusion: The results confirmed the efficacy of tacrolimus (FK506) CTDs in the management of DSS-induced colitis., (© 2020 S. Karger AG, Basel.)

Core-shell-corona chitosan-based micelles were designed for the tumor intracellular pH-triggered doxorubicin (DOX) delivery, via a facile in-situ micellization in an aqueous solution of DOX and polyethylene glycol (PEG) and poly(2-(diisopropylamino) ethyl methacrylate) (PDPA) dual-modified chitosan (PEG-g-CS-g-PDPA). The effect of the PDPA modification on the diameter, drug loading-capacity (DLC) and pH-triggered drug release was investigated for the three different polymerization degrees of PDPA (25, 32, and 42) with a similar modification degree of ~22%. The optimized ones, the core-shell-corona DOX/PEG-g-CS-g-PDPA 32 micelles possessed a mean hydrodynamic diameter (D h ) of 211 nm and DLC of 54%, showing an excellent pH-triggered drug release with negligible premature drug leakage in 60 h. Such results indicated that grafting polycation could efficiently improve the performance of the chitosan-based drug delivery system (DDS) for tumor chemotherapy., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Water-soluble polymer-methotrexate (MTX) conjugates were obtained via efficient carbodiimide-mediated amidation (E = 17-100%). Binding abilities between water-soluble V-shaped or star-shaped copolymers and MTX were studied by isothermal titration calorimetry spectroscopic (UV-vis, NMR) and microscopic (scanning electron microscopy and transmission electron microscopy) techniques. The efficiency of the amidation reaction has depended on the amount of pendant amino alcohol groups and zeta potential (ZP) values of polymeric carries. The sizes of aggregates formed by polymer-drug conjugates in water increased with the number of copolymer arms (202-774 nm at 37°C). Moreover, the conjugates with the high amount of bounded MTX molecules (n MTX  > 78) exhibited negative ZP values. The drug release experiments revealed that the amount of the released MTX depends on pH and can be controlled via shape, topology, and composition of polymeric carrier. Preliminary cytotoxicity studies of V-shaped-MTX conjugate on human immortalized nontumorigenic keratinocyte (HaCaT) cells indicated cytocompatibility of the compound in a wide range of concentrations. The results of our studies have shown that physicochemical and drug release properties of obtained polymer-MTX prodrugs can be tailored via the structure and the topology of the polymeric carrier. Thus conjugates might find the application in a different type of treatment (cancer or psoriasis therapy) and administration (intravenous, dermal, or pulmonary). © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B:2476-2487, 2019., (© 2019 Wiley Periodicals, Inc.)

Lovastatin (LSN), a potent anti-hyperlipidemic drug, possesses poor bioavailability due to its very low aqueous solubility. The objective of this study was to establish a relationship between increased drug solubility before reaching site of absorption or increasing drug solubility at target absorption site for accentuated bioavailability of LSN. Composites of LSN with oppositely natured pH-sensitive acrylate polymers, cationic Eudragit EPO (EPO) and anionic Eudragit L100 (L100), were fabricated with physical trituration and kneading methods. Formulations were characterized for solubility, FTIR, PXRD, DSC, SEM, dissolution and bioavailability studies in rats. Interestingly, we observed that physical mixtures of EPO outmatched its kneaded formulations, whereas the physical mixtures and kneaded dispersions of L100 were virtually similar in characteristics. EPO was superior in boosting LSN solubility in the respective medium than the L100. Moreover, EPO produced immediate release profile in gastric environment whereas L100 offered sustained release of LSN in intestinal milieu. Bioavailability studies in rats further supported the EPO formulation in terms of shorter T max , higher C max and heightened AUC.

The aim of the present study was to investigate the suitability of insoluble Eudragit® water dispersions (NE, NM, RL, and RS) for direct high-shear granulation of very soluble levetiracetam in order to decrease its burst effect from HPMC K100M matrices. The process characteristics, ss-NMR analysis, in vitro dissolution behavior, drug release mechanism and kinetics, texture profile analysis of the gel layer, and PCA analysis were explored. An application of water dispersions directly on levetiracetam was feasible only in a multistep process. All prepared formulations exhibited a 12-hour sustained release profile characterized by a reduced burst effect in a concentration-dependent manner. No effect on swelling extent of HPMC K100M was observed in the presence of Eudragit®. Contrary, higher rigidity of formed gel layer was observed using combination of HPMC and Eudragit®. Not only the type and concentration of Eudragit®, but also the presence of the surfactant in water dispersions played a key role in the dissolution characteristics. The dissolution profile close to zero-order kinetic was achieved from the sample containing levetiracetam directly granulated by the water dispersion of Eudragit® NE (5% of solid polymer per tablet) with a relatively high amount of surfactant nonoxynol 100 (1.5%). The initial burst release of drug was reduced to 8.04% in 30 min (a 64.2% decrease) while the total amount of the released drug was retained (97.02%).

Inflammatory Bowel Diseases (IBD) is a debilitating condition that affects ~70,000 new people every year and has been described as "an expensive disease with no known cure". In addition, IBD increases the risk of developing colon cancer. The current therapeutics for IBD focus on the established disease where the immune dysfunction and bowel damage have already occurred but do not prevent or delay the progression. The current work describes a polymer-based anti-inflammatory technology (Ora-Curcumin-S) specifically targeted to the luminal side of the colon for preventing and/or treating IBD. Ora-Curcumin-S was prepared by molecular complexation of curcumin with a hydrophilic polymer Eudragit® S100 using co-precipitation method. Curcumin interacted with the polymer non-covalently and existed in an amorphous state as demonstrated by various physicochemical techniques. Ora-Curcumin-S is a polymer-drug complex, which is different than solid dispersions in that the interactions are retained even after dissolving in aqueous buffers. Ora-Curcumin-S was >1000 times water soluble than curcumin and importantly, the enhanced solubility was pH-dependent, which was observed only at pHs above 6.8. In addition, around 90% of Ora-Curcumin-S was stable in phosphate buffer, pH 7.4 and simulated intestinal fluid after 24 h, in contrast to 10-20% unformulated curcumin. Ora-Curcumin-S inhibited Monophosphoryl Lipid-A and E. coli induced inflammatory responses in dendritic cells and cells over expressing Toll-Like Receptor-4 (TLR-4) suggesting that Ora-Curcumin-S is a novel polymer-based TLR-4 antagonist. Preliminary pharmacokinetics in mice showed targeted delivery of soluble curcumin to the colon lumen without exposing to the systemic circulation. Furthermore, Ora-Curcumin-S significantly prevented colitis and associated injury in a mouse model of ulcerative colitis estimated using multiple preclinical parameters: colonoscopy pictures, body weight, colon length, colon edema, spleen weight, pro-inflammatory signaling and independent pathological scoring. Overall, the outcome of this innovative proof-of-concept study provides an exciting and locally-targeted pathway for a dietary therapeutic option for IBD patients to help limit colonic inflammation and thus susceptibility to colitis-associated colorectal cancer., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Antimicrobial electrospun nonwoven Eudragit L-100 nanofibrous mats containing Moxifloxacin hydrochloride (MOX-HCL) were fabricated for fast dissolving drug delivery systems (DDSs) associated with wound infection. The morphological characterization of nanofibers using ESEM revealed that the average diameter of non-woven nanofibrous mats ranges 200-600 nm. The nanofiber showed cylindrical shape with crack on the surface. Differential scanning calorimetric (DSC) and Wide Angle X-ray diffraction (WAXRD) demonstrate that the drug exists in an amorphous state in the nanofibers. Nanofibrous mats were also tested for mechanical strength, contact angle, swelling assay, haemolysis and disintegration test. In vitro disintegration tests demonstrated that the dissolution of Eudragit L-100 fiber mats was within 25 s which was higher compared to the pure drug. The Eudragit nanofibers showed pH-dependent drug release profiles, with slow release at pH 1.2 and burst release (around 30 s) at pH 6.8. The in-vitro quantitative and qualitative antimicrobial assay showed that the developed Eudragit L-100 nanofibrous mats with MOX-HCL concentration of 1%, 5% and 15 wt% exhibited antibacterial activities against both gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria. The in-vitro cytotoxicity assay using mouse fibroblast NIH/3T3 cells demonstrated significant biocompatibility of nanofiber mats. As per the results of biological evaluation, Eudragit L-100 nanofibrous mats with 1wt% MOX-HCL could be a suitable substrate for biomedical applications. Eudragit L-100 nanofibrous mats containing Moxifloxacin hydrochloride (MOX-HCL) showed immediate DDSs for localized drug release in the wound infection at slightly acidic or alkaline conditions where faster drug release rate is required for wound healing., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Considering the recent evidence on the therapeutic potential of postbiotics, this study focused on 2 main goals: (1) to develop an enteric microparticle (MP) formulation for intestinal localized delivery of indole-3-aldehyde (3-IAld) (a microbial-derived metabolite produced by the host's lactobacilli during the catabolic pathway of tryptophan) and (2) to provide support in the employment of spray-drying as innovative one-step manufacturing technique for enteric products. For this purpose, special attention was taken in the knowledge of the influence of equipment setup and feedstock properties on MP enteric behavior. Eudragit ® S100 and L100 and ethyl cellulose were used as wall materials and NaOH and ethanol solutions as solvent systems. 3-IAld loading was maintained at 10% w/w. As postulated, feedstock properties influenced spray-drying regime. In addition, they prevailed over other spray-drying process factors in determining MP enteric behavior. Albeit the high buckling regime that produced crumped particles, gastro resistance was obtained by spray-drying 2:1 Eudragit ® S100:L100 with 30% w/w ethyl cellulose in ethanol solution. These results support the use of spray-drying as a method for manufacturing gastro-resistant MP. The obtained 3-IAld-loaded enteric MP will be useful to investigate novel postbiotic-based treatments in different therapeutic areas., (Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.)

Tumors are characterized by leaky blood vessels, and by an abnormal and heterogeneous vascular network. These pathophysiological characteristics contribute to the enhanced permeability and retention (EPR) effect, which is one of the key rationales for developing tumor-targeted drug delivery systems. Vessel abnormality and heterogeneity, however, which typically result from excessive pro-angiogenic signaling, can also hinder efficient drug delivery to and into tumors. Using histidine-rich glycoprotein (HRG) knockout and wild type mice, and HRG-overexpressing and normal t241 fibrosarcoma cells, we evaluated the effect of genetically induced and macrophage-mediated vascular normalization on the tumor accumulation and penetration of 10-20 nm-sized polymeric drug carriers based on poly(N-(2-hydroxypropyl)methacrylamide). Multimodal and multiscale optical imaging was employed to show that normalizing the tumor vasculature improves the accumulation of fluorophore-labeled polymers in tumors, and promotes their penetration out of tumor blood vessels deep into the interstitium., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Incorporation of a desired stimuli-responsive unit in a stereospecific manner at the specific location within a nonlinear block copolymer architecture is a challenging task in synthetic polymer chemistry. Herein, we report a facile and versatile method to synthesize AB 2 miktoarm block copolymers bearing a singlet oxygen ( 1 O 2 )-labile regio and stereospecific β-aminoacrylate linkage with 100% E-configuration at the junction via a combination of amino-yne click chemistry and ring opening polymerization. Using this strategy, a series of 1 O 2 -responsive AB 2 amphiphilic miktoarm (MA) copolymers composed of hydrophilic polyethylene glycol (PEG) as the A constituent and hydrophobic polycaprolactone (PCL) as the B constituent (MA-PEG- b-PCL 2 ) was synthesized by varying the block length of PCL. The self-assembly characteristics of these well-defined MA-PEG- b-PCL 2 copolymers in an aqueous condition were studied by solvent displacement and thin-film hydration method, and their morphologies were investigated using transmission electron microscopy. The copolymers formed spherical, cylindrical, or lamella morphologies, depending on the chain length and preparation conditions. A hydrophobic photosensitizer chlorin e6 (Ce6) and anticancer drug doxorubicin (DOX) were efficiently encapsulated into the hydrophobic core of MA-PEG- b-PCL 2 copolymer micelles. These coloaded micelles were taken up by human breast cancer (MDA-MB-231) cells. Upon red laser light irradiation, the 1 O 2 -generated by the Ce6 induced photocleavage of the β-aminoacrylate moiety, leading to the dissociation of the micellar structure and triggered intracellular drug release for effective therapy. Overall, rapid disassembly upon 1 O 2 generation and subsequent controlled intracellular drug release suggested that these micelles bearing β-aminoacrylate linkage have a huge potential for on-demand drug delivery.

In the present work the feasibility of using inner layer-embedded contact lenses (CLs) to achieve sustained release of highly water soluble drug, betaxolol hydrochloride (BH) on the ocular surface was investigated. Blend film of cellulose acetate and Eudragit S100 was selected as the inner layer, while silicone hydrogel was used as outer layer to construct inner layer-embedded contact lenses. Influence of polymer ratio in the blend film on in vitro drug release behavior in phosphate buffered solution or simulated tear fluid was studied and drug-polymer interaction, erosion and swelling of the blend film were characterized to better understand drug-release mechanism. Storage stability of the inner layer-embedded contact lenses in phosphate buffer solution was also conducted, with ignorable drug loss and negligible change in drug release pattern within 30 days. In vivo pharmacokinetic study in rabbits showed sustained drug release for over 240 h in tear fluid, indicating prolonged drug precorneal residence time. In conclusion, cellulose acetate/Eudragit S100 inner layer-embedded contact lenses are quite promising as controlled-release carrier of highly water soluble drug for ophthalmic delivery., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This study aimed to design the effective formulation of sorafenib (SF) to enhance the oral drug absorption. Three liposomal formulations of SF were prepared including uncoated liposome (SF-Lip), glycol chitosan-coated liposome (GC-SF-Lip), and Eudragit S100-glycol-chitosan coated liposome (SGC-SF-Lip). All formulations showed a narrow size distribution with a high encapsulation efficiency. Both GC-SF-Lip and SGC-SF-Lip exhibited good stability at acidic and neutral pHs without any significant drug leakage, while SF-Lip appeared to be unstable at pH 1.2. In the case of double coated SGC-SF-Lip, its size changed significantly at pH 7.4, due to the dissolution of Eudragit S100 coating layer into the surrounding medium. Compared to SF solution, all liposomal formulations demonstrated a higher cellular uptake in Caco-2 cells. In particular, SGC-SF-Lip displayed a lower cellular uptake than GC-SF-Lip at pH 6.5, but it achieved a similar cellular uptake to GC-SF-Lip at pH 7.4. Consistently, SGC-SF-Lip was less cytotoxic than GC-SF-Lip at pH 6.5, whereas it showed a comparable cytotoxicity to GC-SF-Lip at pH 7.4, implying the removal of the Eudragit S100 coating layer at pH 7.4. After an oral administration to rats, SGC-SF-Lip significantly improved the systemic exposure of SF, where its Cmax and AUC were approximately fourfold higher than the untreated drug. Collectively, SGC-SF-Lip appeared to be promising to enhance the oral absorption of SF., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Colorectal cancer, also known as bowel cancer, is the uncontrolled cell growth in the colon or rectum (parts of the large intestine), or in the appendix. The colon specific drug delivery would alleviate the systemic side effects and would assure the safe therapy for colonic disorders with minimum dose and duration of therapy. The liquisolid technique refers to solubilisation of drug in a non-volatile solvent combined with inclusion of appropriate carrier and coating agent required for tableting. Colon specific degradation of natural polymer, guar gum and pH dependant degradative (pH-7) property of eudragit L100 restricts the delivery of curcumin in gastric and intestinal pH. Formulated curcumin liquisolid powder was evaluated for the micrometric properties, solubility and by differential thermal analysis, X ray powder diffraction and scanning electron microscopy. Curcumin loaded liquisolid tablet showed more anticancer activity against HCT-15 compared with free curcumin. Bioavailability study of the coated and uncoated liquisolid tablets were performed using Newzealand white rabbits. The present study concludes that liquisolid technique is a promising alternative for improving oral bioavailability and dissolution rate of water insoluble drug and coating liquisolid tablet with colon sensitive polymers showed site specific release of drug in the colon., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The integrin α V β 3 receptor emerged as one of the most promising targets owing to its high expression on the surface of various malignant tumour cells and tumour angiogenesis endothelial cells, but with little expression in mature endothelial cells and the majority of normal cells. Here, we report a new targeting ligand FQSIYPpIK (FQS) with high affinity to integrin α V β 3 receptor. To take the advantage of the particular interaction between FQS and integrin α V β 3 receptor, FQS was linked to N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers. A model drug doxorubicin (DOX) was simultaneously conjugated to the same HPMA copolymers via pH-sensitive hydrazone linkages (FQS-HPMA-DOX). In in vitro study, FQS-HPMA-DOX could be internalised into α V β 3 receptor-overexpressed B16F10 cells via a highly specific ligand - receptor pathway (5.0 times and 4.5 times higher cellular internalisation than HPMA-DOX and a scrambled peptide (s)-FQS (sequence: SYFIPKQIp)-modified copolymers ((s)-FQS-HPMA-DOX)). It is worth noting that compared with the classical α V β 3 ligand cRGDfK-modified HPMA copolymers (cRGDfK-HPMA-DOX), FQS-HPMA-DOX also showed superior targeting efficiency. In in vivo study in the B16F10 melanoma bearing mice model showed the antitumour efficiency of FQS-HPMA-DOX (83.9%) were significantly higher than HPMA-DOX (44.9%) and cRGDfK-HPMA-DOX (77.5%). These results suggest that FQS peptide can act as an effective targeting ligand for the delivery of therapeutic agents.

Nanoparticles (NPs) that form by self-assembly of amphiphilic poly(N-(2-hydroxypropyl)-methacrylamide) (pHPMA) copolymers bearing cholesterol side groups are potential drug carriers for solid tumor treatment. Here, we investigate their behavior in solutions of human serum albumin (HSA) in phosphate buffered saline. Mixed solutions of NPs, from polymer conjugates with or without the anticancer drug doxorubicin (Dox) bound to them, and HSA at concentrations up to the physiological value are characterized by synchrotron small-angle X-ray scattering and isothermal titration calorimetry. When Dox is absent, a small amount of HSA molecules bind to the cholesterol groups that form the core of the NPs by diffusing through the loose pHPMA shell or get caught in meshes formed by the pHPMA chains. These interactions are strongly hindered by the presence of Dox, which is distributed in the pHPMA shell, meaning that the delivery of Dox by the NPs in the human body is not affected by the presence of HSA.

In previous studies we showed that the complexation hydrogels based in poly(methacrylic acid-g-ethylene glycol) [P(MAA-g-EG)] rapidly release insulin in the intestine owing to their pH-dependent complexation properties; they also exhibit a high insulin-loading efficiency, enzyme-inhibiting properties, and mucoadhesive characteristics. Cell-penetrating peptides (CPPs), such as oligoarginines [hexa-arginine (R6), comprising six arginine residues], have been employed as useful tools for the oral delivery of therapeutic macromolecules. The aim of our study was to investigate the combination strategy of using P(MAA-g-EG) hydrogels with R6-based CPPs to improve the intestinal absorption of insulin. A high efficiency of loading into crosslinked P(MAA-g-EG) hydrogels was observed for insulin (96.1±1.4%) and R6 (46.6±3.8%). In addition, immediate release of the loaded insulin and R6 from these hydrogels was observed at pH 7.4 (80% was released in approximately 30 min). Consequently, a strong hypoglycemic response was observed (approximately 18% reduction in blood glucose levels) accompanied by an improvement in insulin absorption after the co-administration of insulin-loaded particles (ILP) and R6-loaded particles (ALP) into closed rat ileal segments compared with that after ILP administration alone. These results indicate that the combination of P(MAA-g-EG) hydrogels with CPPs may be a promising strategy for the oral delivery of various insulin preparations as an alternative to conventional parenteral routes.

Background: Polysaccharide based delivery systems have been successfully used to target drugs to colon. In some recent reports, the superiority of concomitant administration of probiotics with such systems has been established. However, the pharmacokinetics of such symbiotic therapy remain unexplored hitherto., Methods: This study deciphers the pharmacokinetic parameters of guar gum based colon targeted spheroids of sulfasalazine with co-administration of probiotics in experimental rats. Thirty rats were divided into five groups using Latin square design. These were subjected to treatment with delayed release formulation, uncoated spheroids, coated spheroid and coated spheroids along with probiotics., Results: In case of delayed release formulation, negligible presence of sulfasalazine in plasma was observed in first 2h, followed by significant increase in sulfasalazine concentration after 3h. Higher plasma concentrations of sulfasalazine were detected for uncoated spheroids with and without probiotics. Negligible release of drug upto 5h and delayed Tmax in case of guar-gum coated sulfasalazine spheroids with or without probiotics clearly indicated successful formulation of colon targeted spheroids. Further, for coated spheroids (both with and without probiotics), the value of Tmax is found to be significantly higher than those with the other treatments., Conclusion: Colon targeted spheroids were therefore, found to reduce absorption of drug which, in turn, is expected to reduce the side effects as only local action in colon is required for treatment of colitis. This is the first report on pharmacokinetic study of a colon targeted delivery system co-administered with probiotics., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

In vitro interaction of osthol (Ost) and fluconazole (FLC) was investigated against 11 fluconazole-resistant clinical isolates of Candida albicans. Synergistic activities were determined using the checkerboard microdilution assay. The results of agar diffusion test confirmed the synergistic interaction. We used an enteric material Eudragit S100 for preparation of Ost nanoparticle (Ost-NP) to improve the oral bioavailability, biological activity of Ost. The physicochemical characteristics of Ost-S100-NP revealed Ost-S100-NP with mean particle size of 55.4±0.4 nm, encapsulation efficiency of 98.95±0.06%, drug loading efficiency of 23.89±0.25%, yield of 98.5±0.1% and a polydispersity index (PDI) of 0.165. As the Ost concentration-time curve showed, Ost-S100-NP can increase the plasma concentration and relative bioavailability of Ost compared with Ost-suspension by oral administration. In vivo, Ost-S100-NP enhanced the therapeutic efficacy of Ost against FLC-resistant C. albicans in immunosuppressed candidiasis mice model. The available information strongly suggests that Ost-S100-NP may be used as a promising compound against drug-resistant fungi.

In this paper, we describe the preparation of polymeric nanoparticles (NPs) loaded with sorafenib for the treatment of hepatocellular carcinoma (HCC). A synthetic brush copolymer, named PHEA-BIB-ButMA (PBB), was synthesized by Atom Trasnfer Radical Polymerization (ATRP) starting from the α-poly(N-2-hydroxyethyl)-d,l-aspartamide (PHEA) and poly butyl methacrylate (ButMA). Empty and sorafenib loaded PBB NPs were, then, produced by using a dialysis method and showed spherical morphology, colloidal size, negative ζ potential and the ability to allow a sustained sorafenib release in physiological environment. Sorafenib loaded PBB NPs were tested in vitro on HCC cells in order to evaluate their cytocompatibility and anticancer efficacy if compared to free drug. Furthermore, the enhanced anticancer effect of sorafenib loaded PBB NPs was demonstrated in vivo by using a xenograft model, by first allowing Hep3B cells to grow subcutaneously into nude mice and then administering sorafenib as free drug or incorporated into NPs via intraperitoneal injection. Finally, in vivo biodistribution studies were performed, showing the ability of the produced drug delivery system to accumulate in a significant manner in the solid tumor by passive targeting, thanks to the enhanced permeability and retention effect., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In the current study, electrostatically-driven pH responsive, supramolecular hydrogels of the trilacunary Wells-Dawson-type 15-tungsto-2-phosphate polyanion (P 2 W 15 ) and chitosan hydrochloride (ChCl) were prepared, using methacrylic acid as pH responsive agent using benzoyl peroxide (BPO) as initiator. The prepared hydrogels were characterized by FT-IR, SEM, XRD and thermal analyses (TGA-DSC). The swelling and pH based P 2 W 15 release profile of the hydrogels showed maximum swellability and release at pH 7.4. Different mathematical models were applied, showing that P 2 W 15 release followed supercase transport-II mechanism and zero-order kinetics. The cytotoxicity results showed that free and embedded P 2 W 15 exhibited dose-dependent cytotoxicity against cancer cell lines (MCF-7; HeLa) with minimal effects on normal cells (Vero). The developed hydrogels were administered to the rabbits for determining the pharmacokinetic behavior of the polyanion. Moreover, the developed hydrogel system as well as polyanion concentration used were also checked for its oral tolerability and safety evaluation in rabbits. The histopathological studies, serum chemistry (except blood glucose level) and hematological investigations exhibited that administered hydrogel suspension at maximal tolerable dose (4000mg/kg body weight) and polyanion concentration used (20mg) were safe from in-vivo point of view. The developed hydrogels exhibited desirable qualities of a drug delivery system that can be used for the delivery of the embedded polyanion., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This study elucidates the physical properties of sono-crystallised micro/nano-sized acetaminophen/paracetamol (PMOL) and monitors its possible transformation from polymorphic form I (monoclinic) to form II (orthorhombic). Hydrophilic Plasdone® S630 copovidone (S630), N-vinyl-2-pyrrolidone and vinyl acetate copolymer, and methacrylate-based cationic copolymer, Eudragit® EPO (EPO), were used as polymeric carriers to prepare drug/polymer binary mixtures. Commercially available PMOL was crystallised under ultra sound sonication to produce micro/nano-sized (0.2-10 microns) crystals in monoclinic form. Homogeneous binary blends of drug-polymer mixtures at various drug concentrations were obtained via a thorough mixing. The analysis conducted via the single X-ray crystallography determined the detailed structure of the crystallised PMOL in its monoclinic form. The solid state and the morphology analyses of the PMOL in the binary blends evaluated via differential scanning calorimetry (DSC), modulated temperature DSC (MTDSC), scanning electron microscopy (SEM) and hot stage microscopy (HSM) revealed the crystalline existence of the drug within the amorphous polymeric matrices. The application of temperature controlled X-ray diffraction (VTXRPD) to study the polymorphism of PMOL showed that the most stable form I (monoclinic) was altered to its less stable form II (orthorhombic) at high temperature (>112°C) in the binary blends regardless of the drug amount. Thus, VTXRD was used as a useful tool to monitor polymorphic transformations of crystalline drug (e.g. PMOL) to assess their thermal stability in terms of pharmaceutical product development and research.

A novel drug release system has been obtained in form of tablets from Eudragit® RS and tenofovir loaded on porous silicon oxycarbide glasses (SiOC). Active carbon (AC) and mesoporous silica (MCM-41) have also been used for comparative purposes. The porous silicon oxycarbide presents a bimodal mesopore size distribution that is maintained after functionalization with amino groups. We have studied the adsorption kinetics and adsorption equilibrium when the materials are loaded with tenofovir and, in all cases, pseudo-second order kinetics and Langmuir isotherm have been revealed as the most representative models describing the kinetic and thermodynamic parameters. Besides, the tenofovir adsorption on these materials turns out to be a favorable process. In vitro release of tenofovir has been studied in simulated vaginal medium by applying different release models. Continuous tenofovir release for >20days has been obtained for the SiOC material functionalized with amine groups. We concluded that the drug release occurs in two steps that involve a drug diffusion step through the material pores and diffusion through the swollen polymer. The interactions between the tenofovir drug and de amine groups of the functionalized silicon oxycarbide also play an important role in the release process., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Novel "zwitterionic" gold nanorods (Au NRs) were constructed through a facile ligand exchange process between cetyltrimethylammonium bromide (CTAB)-Au NRs and the zwitterionic block polymer {poly(2-methacryloyloxyethyl phosohorylcholine)-b-poly(lipoic methacrylate) (pMPC-b-pLA)}. In vitro, they exhibited low dark cytotoxicity and a high therapeutic efficacy to cancer cells. Their blood circulation half-life in vivo (t 1/2 , ∼10 h) was 20-fold longer than that of CTAB-Au NRs (t 1/2 , <30 min). After intravenous administration, they accumulated in tumour sites via an enhanced permeability and retention (EPR) effect and enabled destruction of human xenograft tumours in mice after exposure of the tumour location to NIR laser irradiation at 808 nm. These studies showed that the "zwitterionic" Au NRs had low toxicity and high photothermal efficacy both in vitro and in vivo due to the suprahydrophilic, biocompatible zwitterionic polymer coating layer. They may have the potential to be a promising NIR PTT agent in the biomedical field.

Context: Extensive or long-time use of corticosteroids often causes many toxic side-effects. The ion exchange resins and the coating material, Eudragit, can be used in combination to form a new oral delivery system to deliver corticosteroids., Objectives: The resin microcapsule (DRM) composed by Amberlite 717 and Eudragit S100 was used to target hydrocortisone (HC) to the colon in order to improve its treatment effect on ulcerative colitis (UC) and reduce its toxic side-effects., Methods: Hydrocortisone sodium succinate (HSS) was sequentially encapsulated in Amberlite 717 and Eudragit S100 to prepare the HSS-loaded resin microcapsule (HSS-DRM). The scanning electron microscopy (SEM) was employed to investigate the morphology and structure of HSS-DRM. The in vitro release and in vivo studies of pharmacokinetics and intestinal drug residues in rat were used to study the colon-targeting of HSS-DRM. The mouse induced by 2,4,6-trinitrobenzenesulfonic acid was used to study the treatment of HSS-DRM on experimental colitis., Results: SEM study showed good morphology and structure of HSS-DRM. In the in vitro release study, > 80% of HSS was released in the colon environment (pH 7.4). The in vivo studies showed good colon-targeting of HSS-DRM (T max  = 0.97 h, C max  = 118.28 µg/mL of HSS; T max  = 2.16 h, C max  = 64.47 µg/mL of HSS-DRM). Moreover, the HSS-DRM could reduce adverse reactions induced by HSS and had good therapeutic effects on the experimental colitis., Conclusions: The resin microcapsule system has good colon-targeting and can be used in the development of colon-targeting preparations.

The present investigation was carried out to demonstrate with the help of in vitro and in vivo studies that nanoparticles impregnated ocular inserts effectively delivers significant concentration of drug to the posterior segment of eye after topical administration for treatment of glaucoma. Drug loaded Nanoparticles and their ocular insert have been reported to reduce side effects of orally administered Acetazolamide. Eudragit NPs were prepared by the solvent diffusion nanoprecipitation technique. The prepared NPs were evaluated for various parameters such as particle size, zeta potential, % entrapment efficiency, % drug loading, DSC, FTIR, TEM and stability studies. Ocular inserts of NPs were prepared by solvent casting method. The prepared ocular inserts were evaluated for thickness, content uniformity, folding endurance, disintegration time, morphology and stability study. The NPs and ocular inserts were evaluated for in-vitro drug diffusion study, ex-vivo trans-corneal permeability study, in-vivo ocular tolerability and intra ocular pressure (IOP) reduction study. The optimized batch was stable for a period of 3months in lyophilized form. The optimized formulations had size range of 367nm±8nm, zeta potential around +7mV±1.3mV and 51.61%±3.84% entrapment efficiency with 19%±1.40% drug loading. The ex-vivo trans-corneal study showed higher cumulative corneal permeation, flux across corneal tissue (2.460±0.028μg/ml) and apparent corneal permeability (3.926×10 -6 cm 2 /s & 3.863×10 -6 cm 2 /s) from drug loaded Eudragit NPs and Ocular inserts as compared to drug solution (0.671±0.020μg/ml & 3.166×10 -6 cm 2 /s). In-vivo study showed the Eudragit NPs and ocular insert produced significant (P<0.001) lowering in intra ocular pressure compared with the solution of free drug after 3h of topical ocular administration. Plain Eudragit NPs caused no inflammation and/or discomfort in rabbit eyes and neither affected the intra ocular pressure establishing their safety and non irritancy., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objectives: The objectives of the present investigation were to prepare recombinant human insulin entrapped Eudragit-S100 microspheres containing protease inhibitors and to precisely analyze the outcome of different formulation variables on the microspheres properties using a response surface methodology to develop an optimized formulation with desirable features., Methods: A central composite design was employed to produce microspheres of therapeutic protein by w/o/w multiple emulsion solvent evaporation technique using Eudragit S-100 as coating material and polyvinyl alcohol as a stabilizer. The effect of formulation variables (independent variables) that is levels of Eudragit S-100 (X1), therapeutic protein (X2), volumes of inner aqueous phase (X3) and external aqueous phase (X4) on dependant variables, that are encapsulation efficiency (Y1), drug release at pH 1.2 after 2 h (Y2) and drug release at pH 7.4 after of 2 h (Y3) were evaluated., Results: The significant terms in the mathematical models were generated for each response parameter using multiple linear regression analysis and analysis of variance. All the formulation variables except the volume of external aqueous phase (X4) exerted a significant effect (P <0.05) on drug encapsulation efficiency (Y1) whereas first two variables, namely the levels of Eudragit S-100 (X1) and therapeutic protein (X2) materialized as the determining factors which significantly influenced drug release at pH 1.2 after 2 h (Y2) and drug release at pH 7.4 after of 2 h (Y3). The formulation was numerically optimized by framing the constraints on the dependent and independent variables using the desirability approach. The experimental values for Y1 and Y2 of optimized formulation were found to be 77.65% and 3.64%, respectively which were quite closer to results suggested by software., Conclusion: The results recorded indicate that the recombinant human insulin loaded Eudragit S-100 microspheres containing aprotinin have the benefits of higher loading efficiency, pH responsive and prolonged release characteristics, which may help to carry insulin to the optimum site of absorption., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Anionic Methacrylate Copolymer (AMC) is a fully polymerized copolymer used in the pharmaceutical industry as an enteric/delayed-release coating to permit the pH-dependent release of active ingredients in the gastrointestinal tract from oral dosage forms. This function is of potential use for food supplements. Oral administration of radiolabeled copolymer to rats resulted in the detection of chemically unchanged copolymer in the feces, with negligible absorption (<0.1%). AMC is therefore determined not to be bioavailable. Within a genotoxicity test battery AMC did not show any evidence of genotoxicity in bacteria and mammalian cells. Furthermore, no genotoxic effects occurred in vivo within a micronucleus test. There would therefore appear to be no safety concerns under intended conditions of oral use for the discussed toxicological endpoints., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The formulation and the coating composition of biopolymeric pellets containing ranolazine were studied to improve their technological and biopharmaceutical properties. Eudragit L100 (EU L100) and Eudragit L30 D-55-coated alginate and alginate-hydroxypropylcellulose (HPC) pellets were prepared by ionotropic gelation using 3 concentrations of HPC (0.50%, 0.65%, and 1.00% wt/wt) and applying different percentages (5%, 10%, 20%, and 30% wt/wt) of coating material. The uncoated pellets were regular in shape and had mean diameter between 1490 and 1570 μm. The rate and the entity of the swelling process were affected by the polymeric composition: increasing the HPC concentration, the structure of the pellets became more compact and slowed down the penetration of fluids. Coated alginate-HPC formulations were able to control the drug release at neutral pH: a higher quantity of HPC in the system determined a slower release of the drug. The nature of the coating polymer and the coating level applied affected the drug release in acidic environment: EU L100 gave better performance than Eudragit L30 D-55 and the best coating level was 20%. The pellets containing 0.65% of HPC and coated with 20% EU L100 represented the best formulation, able to limit the drug release in acidic environment and to control it at pH 6.8., (Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.)

In present investigation, recombinant human insulin loaded proliposomes and protamine sulphate coated proliposomes (rh insulin-proliposomes and Pt-rh insulin proliposomes) were encased in Eudragit S100 coated capsule to offer peptide release in simulated intestinal conditions. The particle size and zeta potential of Pt-rh insulin proliposomes were measured to be 583.2±10.2nm/+28.3±3.7mV significantly (P<0.05) higher than 569.7±14.9nm/-37.9±4.3mV and 534.6±24.6nm/-42.7±2.8mV of rh insulin proliposomes and proliposomes, respectively. Next, shape and surface morphology analysis pointed out the successful transformation of proliposomes in to spherical shaped liposomes. Furthermore, in vitro release study specified that free rh insulin solution encapsulated in uncoated gelatine capsule released 97.8% of peptide within 1h in SGF (pH~1.2). On other hand, rh insulin-proliposomes and Pt-rh insulin proliposomes encased in Eudragit S100 coated capsule released 93.2% and 81.6% of peptide, up to 24 h in SIF (pH~7.2). SDS-PAGE and circular dichroism (CD) ascertained the stability and intactness of isolated rh insulin from tailored dosage forms. In last, cellular uptake in Caco-2 cells indicating the superiority of Pt-rh insulin proliposomes in comparison to rh-insulin proliposomes and free rh insulin solution, respectively. In conclusion, Pt-rh insulin proliposomes displayed promising results and may be considered for further investigations., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Conjugating therapeutic proteins and peptides to poly(ethylene glycol) (PEG) can improve their pharmacokinetics and therapeutic potential. However, PEGylation suffers from non-specific conjugation, low yield and immunogenicity. Herein we report a new and general methodology to synthesize a protein-polymer conjugate with site-specificity, high yield and activity, long circulation half-life and excellent therapeutic efficacy. A phospholipid polymer, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), was grown solely from the C-terminus of interferon-alpha to form a site-specific (C-terminal) and stoichiometric (1:1) PMPC conjugate of interferon-alpha in high yield. Notably, the PMPC conjugate showed 194- and 158-fold increases in systemic exposure and tumor uptake as compared with interferon-alpha, respectively. The in vitro antiproliferative bioactivity of the PMPC conjugate was 8.7-fold higher than that of PEGylated interferon-alpha (PEGASYS). In a murine cancer model, the PMPC conjugate completely inhibited tumor growth and cured 75% mice, whereas at the same dose, no mice treated with interferon-alpha or PEGASYS survived. We believe that this new approach to synthesize C-terminal protein conjugates of PMPC may be applicable to a large subset of protein and peptide drugs, thereby providing a general platform for the development of next-generation protein therapeutics., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Psoralidin (PL) has recently been attracting more attention as a new anticancer agent candidate. Nevertheless, peroral administration of PL is largely challenged by its insoluble nature and intestinal efflux. This article aimed to develop a nanoencapsulation formulation of PL using water-soluble chitosan and Eudragit S100 and to evaluate its potential for bioavailability enhancement. PL-loaded nanocapsules (PL-NCs) were prepared by a solvent diffusion and high-pressure homogenization technique with Poloxamer 188 as a stabilizer. The resultant PL-NCs were approximately 132.5nm in particle size and possessed a high entrapment efficiency (98.1%). In vitro release showed that PL was released less from the nanocapsules due to electrostatic complexation. A lipolytic experiment demonstrated that our prepared PL-NCs were not degraded by lipase, in contrast with the most commonly used lipid nanoparticles. Furthermore, PL-NCs appeared to have less affinity for intestinal mucins. Following oral administration, the bioavailability of PL was significantly enhanced via the PL-NCs, with a value of 339.02% relative to the reference (suspensions). Excellent intestinal adhesion and transepithelial permeability accounted for the enhancement of oral bioavailability. Taken together, these results indicate that nanoencapsulation of PL with chitosan and Eudragit S100 is a promising strategy for improved PL oral delivery., (Copyright © 2016. Published by Elsevier B.V.)

Unlabelled: Nanomedicines have emerged as indispensable platforms for cancer theranostics, however, the therapeutic outcomes were often compromised not only by the multiple biological barriers during the itinerary from the initial injection site to the intracellular action site but also the insufficient drug release at the pathological site. Herein, novel bioreducible double head agent, combining reversible addition-fragmentation chain transfer agent and ring opening polymerization initiator through disulfide linkage, was firstly prepared. Well-defined cRGDfK-polycarboxybetaine methacrylate-SS-polycaprolactone block copolymers (termed as cRGD-PCSSL) were facilely synthesized using this initiator. Subsequently, shell sheddable and drug-encapsulated zwitterionic nanoparticles were constructed by one-step self-assembly with doxorubicin (DOX) (termed as cRGD-PCSSL/DOX NPs). The reduction-responsive shedding of PCB shells resulted in the rapid loss of cRGD-PCSSL/DOX NPs stability in the presence of glutathione, facilitating the rapid DOX release. Results of flow cytometry and fluorescence microscopy demonstrated that cRGD-PCSSL/DOX NPs could be internalized by HepG2 cells via receptor-mediated endocytosis with fast intracellular drug release, leading to considerable cytotoxicity in comparison with free DOX. Importantly, the low protein adsorption and excellent serum stability properties of cRGD-PCSSL/DOX NPs translated into prolonged systemic circulation and enhanced tumor accumulation. Furthermore, intravenous injection of cRGD-PCSSL/DOX NPs in tumor-bearing mice exhibited significantly higher antitumor efficiency and lower systemic toxicity compared to free DOX. Consequently, the novel zwitterionic NPs, which facilely overcome the dilemma between multifunctionality and complexity by programmatically circumventing the multiple biological barriers, would represent a promising platform for enhanced anticancer drug delivery., Statement of Significance: Herein, novel bioreducible RAFT and ROP double-head agent was first reported for the synthesis of cRGDfK-polycarboxybetaine methacrylate-SS-polycaprolactone zwitterionic block copolymers (cRGD-PCB-SS-PCL, termed as cRGD-PCSSL) through controllable polymerization methods. Firstly, this synthetic route surmounted the major disadvantage of most current used methods, which required thiol exchange reaction between active disulfide bond and free thiol groups at the chain ends. Secondly, the prepared cRGD-PCSSL/DOX NPs reasonably integrated cRGD for active tumor targeting and receptor-mediated endocytosis, zwitterionic PCB with nonfouling property for prolonged systemic circulation, disulfide linkage for reduction-responsive drug release, biodegradable PCL for hydrophobic anticancer drug loading. Finally, the systematic evaluation fully verified that the in vitro optimized cRGD-PCSSL/DOX NPs translated into significantly better therapeutic efficiency with reduced side effects in vivo., (Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

While highly effective for slowing cancer progression in principle, the c-Myc inhibitor peptide H1-S6A,F8A (H1) has not performed well in tumor studies, in part because it does not pass efficiently through the nuclear envelope. Here we describe a dual-strike strategy in which tumor cells were treated first with N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer-docetaxel (DTX) conjugates (P-DTX), which arrested cells in the G2/M phase and prolonged the period when the nuclear membrane was disassembled. In the second strike, the cells were then treated with P-H1 conjugates, which entered the nucleus and efficiently inhibited c-Myc. The in vitro studies demonstrated that the combination of P-DTX and P-H1 conjugates was sequence-dependent, and P-DTX followed by P-H1 had synergism, which was significantly more effective than reverse sequential delivery, simultaneous co-delivery or monotherapy with P-DTX or P-H1 alone. The in vivo studies showed that sequential delivery of P-DTX followed by P-H1 remarkably slowed the tumor growth and improved the animal survival. This sequential, dual-strike approach provides new opportunities for nuclear-targeted anticancer drug delivery., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Antiadherents are used to decrease tackiness of a polymer coating during both processing and subsequent storage. Despite being a common excipient in coating formulae, antiadherents may affect mechanical properties of the coating film as well as drug release from film-coated tablets, but how could addition of antiadherents affect these properties and to what extent and is there a relation between the physical characteristics of the tablet coat and the drug release mechanisms? The aim of this study was to evaluate physical characteristics of films containing different amounts of the antiadherents talc, glyceryl monostearate, and PlasACRYL(TM) T20. Eudragit RL30D and Eudragit RS30D as sustained release polymers and Eudragit FS30D as a delayed release material were used. Polymer films were characterized by tensile testing, differential scanning calorimetry (DSC), microscopic examination, and water content as calculated from loss on drying. The effect of antiadherents on in vitro drug release for the model acetylsalicylic acid tablets coated with Eudragit FS30D was also determined. Increasing talc concentration was found to decrease the ability of the polymer films to resist mechanical stress. In contrast, glyceryl monostearate (GMS) and PlasACRYL produced more elastic films. Talc at concentrations higher than 25% caused negative effects, which make 25% concentration recommended to be used with acrylic polymers. All antiadherents delayed the drug release at all coating levels; hence, different tailoring of drug release may be achieved by adjusting antiadherent concentration with coating level.

Biodegradable materials used for drug delivery are of great demand due to their ability to degrade into low molecular weight species and further excrete from the body by metabolism. Herein, we report a new kind of zinc(II) crosslinked poly(methacrylic acid) nanohydrogels (ZCLNs) inspired by zinc finger proteins with dual stimuli-triggered degradation (glutathione and pH) for the first time. Compared with the disulfide bond crosslinked nanohydrogels, this new kind of ZCLNs is beneficial to the degradation of a wide range of cells, including normal cells. Ex vivo fluorescence images showed that the DOX-loaded folate-PEG conjugated zinc(II)-crosslinked polymeric nanohydrogels (FPZCLNs-15) preferentially accumulated in tumor tissue and the accumulation in normal tissues was much less compared with DOX-loaded PZCLNs-15 (non-targeted nanohydrogels) and free DOX, the FPZCLNs-15 (targeting system) delivered DOX to the tumor site with approximately 3.6- and 1.6-fold higher than free DOX and PZCLNs-15, respectively. Meanwhile, the PZCLNs-15 and FPZCLNs-15 reduced the concentration of DOX in the heart by 3.2- and 5.0-fold respectively, as compared to the free DOX. Moreover, a superior tumor growth inhibition and negligible damage to normal organs like the heart and kidney, which is reported to be vulnerable to DOX-associated side effects, are further demonstrated., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Curcumin is a natural dietary compound with demonstrated potential in preventing/treating several chronic diseases in animal models. However, this success is yet to be translated to humans mainly because of its poor oral bioavailability caused by extremely low water solubility. This manuscript demonstrates that water insoluble curcumin (~1μg/ml) forms highly aqueous soluble complexes (>2mg/ml) with a safe pH sensitive polymer, poly(butyl-methacrylate-co-(2-dimethylaminoethyl) methacrylate-co-methyl-methacrylate) when precipitated together in water. The complexation process was optimized to enhance curcumin loading by varying several formulation factors. Acetone as a solvent and polyvinyl alcohol as a stabilizer with 1:2 ratio of drug to polymer yielded complexes with relatively high loading (~280μg/ml) and enhanced solubility (>2mg/ml). The complexes were amorphous in solid and were soluble only in buffers with pHs less than 5.0. Hydrogen bond formation and hydrophobic interactions between curcumin and the polymer were recorded by infrared spectroscopy and nuclear magnetic resonance spectroscopy, respectively. Molecular complexes of curcumin were more stable at various pHs compared to unformulated curcumin. In mice, these complexes increased peak plasma concentration of curcumin by 6 times and oral bioavailability by ~20 times. This is a simple, economic and safer strategy of enhancing the oral bioavailability of curcumin., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Responsive block copolymer micelles emerging as promising imaging and drug delivery systems show high stability and on-demand drug release activities. Herein, we developed self-assembled pH-responsive NIR emission micelles entrapped with doxorubicin (DOX) within the cores by the electrostatic interactions for fluorescence imaging and chemotherapy applications. The block copolymer, poly(methacrylic acid)-block-poly[(poly(ethylene glycol) methyl ether methacrylate)-co-boron dipyrromethene derivatives] (PMAA-b-P(PEGMA-co-BODIPY), was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization, and the molecular weight distribution of this copolymer was narrow (Mw/Mn = 1.31). The NIR fluorescence enhancement induced by the phenol/phenolate interconversion equilibrium works as a switch in response to the intracellular pH fluctuations. DOX-loaded PMAA-b-P(PEGMA-co-BODIPY) micelles can detect the physiological pH fluctuations with a pKa near physiological conditions (∼7.52), and showed pH-responsive collapse and an obvious acid promoted anticancer drug release behavior (over 58.8-62.8% in 10 h). Real-time imaging of intracellular pH variations was performed and a significant chemotherapy effect was demonstrated against HeLa cells.

Well-defined water-soluble block copolymers poly(ethylene glycol)-b-poly(N-(2-hydroxypropyl) methacrylamide-co-N-methacryloylglycylglycine) (PEG-b-P(HPMA-co-MAGG)) and their doxorubicin (Dox) conjugates with different composition and molecular weight were synthesized. These Dox conjugates can form micelles in buffer solution. The physicochemical properties, in vivo biodistribution, blood clearance, and especially the tumor accumulation of copolymers and micelles were studied. Severe liver accumulation can be observed for PEG-b-PMAGG copolymers. This was quite different from their Dox conjugate for which decreased RES uptake and elevated kidney accumulation could be observed. When decrease the negative charge to an appropriate amount such as 8-10 mol %, both RES uptake and kidney accumulation could be suppressed. Obvious tumor accumulation could be achieved especially when the molecular weight were increased from ∼40 to ∼80 KDa. These results provided us with a guideline for the design of nanoscaled drug delivery system as well as a potential option for treating kidney-related cancers.

The present study is designed and significantly planned to study the effect of double-compression coating on core mini-tablets to attain the chronopharmaceutical delivery of ketorolac tromethamine to colon. Double-compression coated tablets were prepared based on time-controlled hydroxypropyl methylcellulose K100M inner compression coat and pH-sensitive Eudragit S100 outer compression coat. From the in vitro drug release studies, F6 tablets was considered as the optimized formulation, which retarded the drug release in stomach and small intestine (3.51 ± 0.15% in 5h) and progressively released to colon (99.82 ± 0.69% in 24h). The release process followed supercase-II transport with zero order release kinetics. Similarity factor calculated from stability studies was found to be 84.73. From the pharmacokinetic evaluation, the immediate release core mini-tablets reached peak plasma concentration (Cmax of 4532.68 ± 28.14 ng/ml) at 2h Tmax and colon targeted tablets showed Cmax=3782.29 ± 17.83 ng/ml at 12h Tmax. The area under the curve and mean resident time of core mini-tablets were found to be 11,278.26 ± 132.67 ng-h/ml and 3.68 h respectively while 17,324.48 ± 56.32 ng-h/ml and 10.39 h for compression coated tablets. Hence the development of double-compression coated tablets is a promising way to gain the chronopharmaceutical delivery of ketorolac tromethamine to colon., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Using a simple solution mixing method, curcumin was dispersed in the matrix of Eudragit® E PO polymer. Water solubility of curcumin in curcumin-Eudragit® E PO solid dispersion (Cur@EPO) was greatly increased. Based on the results of several tests, curcumin was demonstrated to exist in the polymer matrix in amorphous state. The interaction between curcumin and the polymer was investigated through Fourier transform infrared spectroscopy and (1)H NMR which implied that OH group of curcumin and carbonyl group of the polymer involved in the H bonding formation. Cur@EPO also provided protection function for curcumin as verified by the pH challenge and UV irradiation test. The pH value influenced curcumin release profile in which sustained release pattern was revealed. Additionally, in vitro transdermal test was conducted to assess the potential of Cur@EPO as a vehicle to deliver curcumin through this alternative administration route., (Copyright © 2015 Elsevier B.V. All rights reserved.)

A (13)C-enriched phosphorylcholine polymer ((13)C-PMPC) as a self-traceable MR (magnetic resonance) tag was conjugated with a fragment (scFv) of Herceptin, a clinical antibody against antigen Her2. When injected in model mice bearing Her2(+) (gastric) and Her2(-) (pancreatic) tumors, the antibody-tag conjugate (13)C-PMPC-scFv selectively accumulated in the Her2(+) tumor with a rapid build-up/decay (accumulation/clearance) profile and, with the use of the (1)H-(13)C double-resonance (heteronuclear correlation) technique, the Her2(+) gastric tumor was clearly MR imaged., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

This study was undertaken in order to apply a synthesized interpolyelectrolyte complex (IPEC) of polymethacrylate and carboxymethylcellulose as a controlled release oral tablet matrix for the delivery of the model neuroactive drug levodopa. The IPEC (synthesized in Part I of this work) was characterized by techniques such as Fourier Transform Infra-Red (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC), Advanced DSC (ADSC), and Scanning Electron Microscopy (SEM). The tablet matrices were formulated and characterized for their drug delivery properties and in vitro drug release. FTIR confirmed the interaction between the two polymers. The IPEC composite generated tablet matrices with a hardness ranging from 19.152-27.590 N/mm and a matrix resilience ranging between 42 and 46%. An IPEC of polymethacrylate and carboxymethylcellulose was indeed an improvement on the inherent properties of the native polymers providing a biomaterial with the ability to release poorly soluble drugs such as levodopa at a constant rate over a prolonged period of time., (© 2014 Wiley Periodicals, Inc.)

This study was undertaken to synthesize an interpolyelectrolyte complex (IPEC) of polymethacrylate (E100) and sodium carboxymethylcellulose (NaCMC) to form a polymeric hydrogel material for application in specialized oral drug delivery of sensitive levodopa. Computational modeling was employed to proffer insight into the interactions between the polymers. In addition, the reactional profile of NaCMC and polymethacrylate was elucidated using molecular mechanics energy relationships (MMER) and molecular dynamics simulations (MDS) by exploring the spatial disposition of NaCMC and E100 with respect to each other. Computational modeling revealed that the formation of the IPEC was due to strong ionic associations, hydrogen bonding, and hydrophilic interactions. The computational results corroborated well with the experimental and the analytical data., (© 2014 Wiley Periodicals, Inc.)

Abstract Duchenne muscular dystrophy (DMD) is a severe hereditary neuromuscular disorder caused by mutations in the dystrophin gene. Antisense-mediated targeted exon skipping has been shown to restore dystrophin expression both in DMD patients and in the mdx mouse, the murine model of DMD, but the ineffective delivery of these molecules limits their therapeutic use. We demonstrated that PMMA/N-isopropil-acrylamide (ZM2) nanoparticles (NPs), administered both intraperitoneally and orally, were able to deliver 2'OMePS antisense inducing various extents of dystrophin restoration in the mdx mice. Defining NP biodistribution is crucial to improve effects on target and dose regimens; thus, we performed in vivo studies of novel ZM4 NPs. ZM4 are conjugated with NIR fluorophores as optical probes suitable for studies on the Odyssey Imaging System. Our results indicate that NPs are widely distributed in all body muscles, including skeletal muscles and heart, suggesting that these vehicles are appropriate to deliver antisense oligonucleotides for targeting striated muscles in the DMD animal model, thus opening new horizons for Duchenne therapy.