Formulation optimization of ginkgo flavonoids matrix tablets by orthogonal design / 中国中药杂志

Sustained-release tablet has become one of the hottest research spots in the area of sustained release preparations with its unique advantages. At present, a series of shortcomings were exited in the ordinary ginkgo preparations, which were used for the treatment of cardiovascular and cerebrovascular diseases. In order to avoid these shortcomings, ginkgo flavonoids matrix tablets were prepared in this paper. Furthermore, the amount and varieties of matrix material, adhesives and fillers were investigated. Meanwhile, the formulation was optimized by using the method of orthogonal design, and Zero-order, First-order, Higuchi, Ritger-peppas equation were used for the model fitting and mechanism discussing of drug release.

Preparation of valsartan nanosuspensions and its in vitro dissolution / 药学学报

To increase the dissolution rate and extent of valsartan, valsartan nanosuspensions have been prepared. Controlled precipitation assisted with sonication is utilized to prepare valsartan nanosuspensions, the concentration of the drug, stabilizer and costablizer had a great effect on the stability of the preparation according to the pre-experiment. So the method of central composite design-response surface is used to optimize the prescription based on the above three factors and the particle size as the response value. The software Origin 8.0 is used to draw the view of the three-dimensional effects and 2D contour map, to get the optimal prescription area. Valsartan nanosuspensions were prepared. The mean diameter and zeta potential are about 216.6 nm and -57.7 mV, respectively. Compared with the microsuspensions and commercial preparation, the dissolution of valsartan nanosuspensions was faster and the bioavailability can be enhanced to some extent.