In vitro evaluation of saxagliptin and metformin hydrochloride sustained-release tablets / 中国药科大学学报

@#In order to evaluate the consistency of the release behavior between the self-made saxagliptin and metformin hydrochloride sustained-release tablets and the reference preparations in vitro, the similarity of the dissolution curves between the self-made preparations and the reference preparations in four dissolution mediums: HCl (pH 1.0), acetate buffer saline (pH 4.5), phosphate buffer saline (pH 6.8) and pure water, and the gel morphology and strength of the self-made preparations and the reference preparations in the HCl (pH 1.0) solution medium were compared.Results showed that in four dissolution mediums, the dissolution rates of saxagliptin in the self-made preparations and the reference preparations at 15 min were greater than 85%, and the ?2 similarity factors of metformin hydrochloride were 89, 83, 80, 86, all greater than 50, so the dissolution of the self-made preparations was consistent with those of the reference preparations.The volume expansion rate, water absorption rate and erosion rate were consistent with those of the reference preparations, and the gel strength of the self-made preparations was the same as that of the reference preparations.The in vitro release behaviors of the self-made preparations and the reference preparations are consistent, which provide a good guarantee for bioequivalence.

Preparation and performance evaluation of matrine-loaded thermosensitive in situ gel for rectum / 中草药

Objective: Optimize to obtain the in situ gel of matrine with thermosensitivity and rectal retention of bioadhesion rectum. Methods: Thermosensitive gel was prepared by cold method, and then using gelation temperature as an indicator, central combination design-response surface method (CCD-RSM) was used to optimize the dosage of P407, P188, and CMC-Na. Texture Analyzer was used to measure the gel strength and adhesion of prescription, the rectal retention was investigated by rectal administration, and the release rate was explored by modified paddle method. Results: The optimal prescription was matrine 2%, CMC-Na 1.0%, P188 1.3%, P407 16.5%, and benzalkonium bromide 0.02%. The prescription gel did not leak after rectal administration in rats, which can remain in the body for more than 6 h, in vitro release in line with Weibull model. Conclusion: The optimized matrine-loaded thermosensitive in situ gel could meet the requirement of rectal administration.

Preparation of nanogels with different gelation speeds as embolization and drug delivery materials and evaluation of their capacity / 中国药学杂志

OBJECTIVE: To design nanogels with different phase transition speeds and screen embolization and drug delivery materials that can be used for transcatheter arterial chemoembolization (TACE). METHODS: Random copolymer PNA nanogels and interpenetrating polymer PNA-IPN nanogels, in which the ratio of co-monomers between N-isopropylacrylamide (NIPAM) and acrylic acid (AA) were 3∶1, 2∶1 and 1∶1, respectively, were prepared by emulsion polymerization. The embolization and drug-loaded capacities of nanogels were evaluated by characterization of their particle morphology, temperature sensitivity, solution phase transition behavior and rheological properties. RESULTS: Nanogel particles were relatively uniform spheres. The particle size of PNA was 386-795 nm, and the particle size of PNA-IPN was 367-750 nm. The increase of temperature led to the decrease of particle size, while the increase of the ratio of the co-monomer AA caused the decrease of temperature sensitivity and gel strength of nanogels, and the increase of the phase transition temperature and the gelation speed. Compared with PNA, PNA-IPN-2 had slightly smaller particle size, lower gelation temperature, faster gelation speed and significantly increased gel strength. The PNA-IPN-2 could load doxorubicin by charge action with 10.3% of loading efficiency. CONCLUSION: The 140 mg•mL-1 PNA-IPN-2 solution has suitable gelation temperature, gelation speed and gel strength. The shearthinning nature and drug release feature are very favorable for TACE, so the PNA-IPN-2 solution is promising for the applications in TACE as nanogels embolization and drug delivery materials.

A new method for extracting agarose using basic resin / 中国海洋药物

Objective To study a new method for extracting agarose. Methods In 1.5% agar solution, adding the cation resin exchanged by NH~+_ 4 to take off metal ions, then using the OH~ - basic resin to absorb agaropectin. Results and Conclusion The extracting rate was 57%, gel strength reached 560 g/ cm~ 2 , the agarose has good electricity function by measuring the gentian violet electrophoresis and the DNA gel electrophoresis, so it is suitable for bioche- mistry and molecular biology electrophoresis. It is a kind of simple and low cost method for extracting agarose which better than the EDTA- 2Na method and DEAE cellulose method.

Rheological properties and gel properties of agar / 中国海洋药物

Objective Rheological properties and gelation properties of agar were investigated. Methods The gelling point,melting point and the gel strength of agar were detected with MCR101 rheometer and TA texture testing instrument. Results and Conclusion Rheological properties of agar were affected by its concentration ,temperature and the addition of salt (such as NaCl ,CaCl2) and sucrose. Apparent viscosity exhibited shear thinning behavior following the power law model. Apparent viscosity increased with the increase of concentration,and decreased with the rise of temperature. The decrease in viscosity followed an Arrhenius temperature dependence. Agar solutions exhibited typical "weak gel" properties by small strain oscillatory measurements. The results indicated that the agar solution was characterized as a gel properties ,and which could form a kind of heat reversible gel. The gelling point of agar was lower than its melting point. The gel strength of agar could be affected by its gel time,and the addition of salt (such as NaCl,CaCl2) and sucrose.