PVP/aprepitant microcapsules produced by supercritical antisolvent process.

The supercritical antisolvent (SAS) process was a green alternative to improve the low bioavailability of insoluble drugs. However, it is difficult for SAS process to industrialize with limited production capacity. A coaxial annular nozzle was used to prepare the microcapsules of aprepitant (APR) and polyvinylpyrrolidone (PVP) by SAS with N, N-Dimethylformamide (DMF) as solvent. Meanwhile, the effects of polymer/drug ratio, operating pressure, operating temperature and overall concentration on particles morphology, mean particle diameter and size distribution were analyzed. Microcapsules with mean diameters ranging from 2.04 µm and 9.84 µm were successfully produced. The morphology, particle size, thermal behavior, crystallinity, drug content, drug dissolution and residual amount of DMF of samples were analyzed. The results revealed that the APR drug dissolution of the microcapsules by SAS process was faster than the unprocessed APR. Furthermore, the drug powder collected every hour is in the kilogram level, verifying the possibility to scale up the production of pharmaceuticals employing the SAS process from an industrial point of view.

Novel tetrahydrobenzo[b]thiophen-2-yl)urea derivatives as novel α-glucosidase inhibitors: Synthesis, kinetics study, molecular docking, and in vivo anti-hyperglycemic evaluation.

α-Glucosidase inhibitors, which can inhibit the digestion of carbohydrates into glucose, are one of important groups of anti-type 2 diabetic drugs. In the present study, we report our effort on the discovery and optimization of α-glucosidase inhibitors with tetrahydrobenzo[b]thiophen-2-yl)urea core. Screening of an in-house library revealed a moderated α-glucosidase inhibitors, 5a, and then the following structural optimization was performed to obtain more efficient derivatives. Most of these derivatives showed increased inhibitory activity against α-glucosidase than the parental compound 5a (IC50 of 26.71 ± 1.80 µM) and the positive control acarbose (IC50 of 258.53 ± 1.27 µM). Among them, compounds 8r (IC50 = 0.59 ± 0.02 µM) and 8s (IC50 = 0.65 ± 0.03 µM) were the most potent inhibitors, and showed selectivity over α-amylase. The direct binding of both compounds with α-glucosidase was confirmed by fluorescence quenching experiments. Kinetics study revealed that these compounds were non-competitive inhibitors, which was consistent with the molecular docking results that compounds 8r and 8s showed high preference to bind to the allosteric site instead of the active site of α-glucosidase. In addition, compounds 8r and 8s were not toxic (IC50 > 100 µM) towards LO2 and HepG2 cells. Finally, the in vivo anti-hyperglycaemic activity assay results indicated that compounds 8r could significantly decrease the level of plasma glucose and improve glucose tolerance in SD rats treated with sucrose. The present study provided the tetrahydrobenzo[b]thiophen-2-yl)urea chemotype for developing novel α-glucosidase inhibitors against type 2 diabetes.

Overcoming Multiple Absorption Barrier for Insulin Oral Delivery Using Multifunctional Nanoparticles Based on Chitosan Derivatives and Hyaluronic Acid.

BACKGROUND: Although dynamics and uses of modified nanoparticles (NPs) as orally administered macromolecular drugs have been researched for many years, measures of molecule stability and aspects related to important transport-related mechanisms which have been assessed in vivo remain as relatively under characterized. Thus, our aim was to develop a novel type of oral-based delivery system for insulin and to overcome barriers to studying the stability, transport mechanisms, and efficacy in vivo of the delivery system. METHODS: NPs we developed and tested were composed of insulin (INS), dicyandiamide-modified chitosan (DCDA-CS), cell-penetrating octaarginine (r8), and hydrophilic hyaluronic acid (HA) and were physically constructed by electrostatic self-assembly techniques. RESULTS: Compared to free-insulin, levels of HA-DCDA-CS-r8-INS NPs were retained at more desirable measures of biological activity in our study. Further, our assessments of the mechanisms for NPs suggested that there were high measures of cellular uptake that mainly achieved through active transport via lipid rafts and the macropinocytosis pathway. Furthermore, investigations of NPs indicated their involvement in caveolae-mediated transport and in the DCDA-CS-mediated paracellular pathway, which contributed to increasing the efficiency of sequential transportation from the apical to basolateral areas. Accordingly, high efficiency of absorption of NPs in situ for intestinal loop models was realized. Consequently, there was a strong induction of a hypoglycemic effect in diabetic rats of NPs via orally based administrations when compared with measures related to free insulin. CONCLUSION: Overall, the dynamics underlying and influenced by HA-DCDA-CS-r8-INS may hold great promise for stability of insulin and could help overcome interference by the epithelial barrier, and thus showing a great potential to improve the efficacy of orally related treatments.

Preparation and Release Profiles in Vitro/Vivo of Galantamine Pamoate Loaded Poly (Lactideco-Glycolide) (PLGA) Microspheres.

Patient's poor compliance and the high risk of toxic effects limit the clinical use of galantamine hydrobromide. To overcome these drawbacks, the sustained-release galantamine pamoate microspheres (GLT-PM-MS) were successfully developed using an oil/water emulsion solvent evaporation method in this study. Physicochemical properties of GLT-PM-MS were carefully characterized, and the in vitro and in vivo drug release behaviors were well studied. Results showed that the morphology of optimized microspheres were spherical with smooth surfaces and core-shell interior structure. Mean particle size, drug loading and entrapment efficiency were 75.23 ± 1.79 µm, 28.01 ± 0.81% and 87.12 ± 2.71%, respectively. The developed GLT-PM-MS were found to have a sustained release for about 24 days in vitro and the plasma drug concentration remained stable for 17 days in rats. These results indicated that GLT-PM-MS could achieve the sustained drug release purpose and be used in clinical trial.