In vitro dissolution and physicochemical characterizations of novel PVP-based solid dispersions containing valsartan prepared by a freeze-drying method

Valsartan [VAL] shows poor oral bioavailability mainly as a result of its low water solubility at low pH. This study is designed to investigate the dissolution properties and physicochemical characteristics of novel PVP-based solid dispersions [SDs] containing VAL. The SDs were prepared with polyvinylpyrrolidone [PVP-K30] as a hydrophilic polymer, sodium hydroxide [NaOH] as an alkalizer, and poloxamer 188 [F68] as a surfactant, without using any organic solvents by a freeze-drying method. The dissolution study was carried out and the physicochemical properties of SDs were also characterized by using differential scanning calorimetry [DSC], fourier transform-infrared [FT-IR] spectroscopy, X-ray diffractometry [XRD] and scanning electron microscopy [SEM]. The dissolution rates of SDs were significantly improved at pH 1.2 and pH 6.8 compared to that of pure drug. The results of physicochemical properties suggested that some interactions between VAL and carriers had occurred in the molecular level and the drug presented in the SDs was amorphous. It was concluded that the novel PVP-based SDs has been successfully prepared by a freeze-drying method, resulting in significant dissolution improvement of VAL

Preparation, in vitro evaluation of excipient-free dry powder inhalation of extraction of Trollius chinensis / 中国中药杂志

To prepare and evaluate dry powder inhalation (DPI) of extraction of Trollius chinensis Bunge (TCB). Orthodox design was employed to optimize the parameters of spray drying to prepare micronized TCB powder, the DPI was prepared by mixing micronized TCB powder and lactose. The results showed that the fine particle fraction (FPF) and emitted dose (ED) of micronized TCB powder was (21.07 +/- 1.74)%, (75.31 +/- 21.05)%, respectively, and for DPI was (56.4 +/- 2.2)%, (95.9 +/- 3.0)%, respectively. Therefore, the prepared DPI meeted requirements in the Chinese Pharmacopeia, indicating a good application prospect.

Preparation and evaluation of valerian oil-beta-cyclodextrin inclusion complex / 中国中药杂志

The aim of this study was to improve the stability and cover the unpleasant odor of valerian oil by preparation of beta-cyclodextrin inclusion complex. The preparation method was established based on the yield of inclusion complex and entrapment efficiency of valerian volatile oil. After that, the formulation and processing parameters were optimized by uniform design table. The formations of inclusion complex were validated by DSC and X-RD method. The stability of valerian oil beta-cyclodextrin inclusion was studied under stressed conditions. In conclusion, relatively high yield of inclusion complex and entrapment efficiency were obtained by saturated solution-ultrasonication method. Inclusion complex yield and entrapment efficiency of the valerian oil were (84.78 +/- 3.23)% and (86.23 +/- 2.48)%, which were prepared under the optimized conditions, respectively. The results of DSC and X-RD were indicated the formation of inclusion complex. The stability of test showed that the valerian oil-beta-cyclodextrin inclusion complex was improved significantly.