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.

Preparation of coated tablets of glycyrrhetic acid-HP-beta-cyclodextrin tablets for colon-specific release / 中国中药杂志

<p><b>OBJECTIVE</b>To prepare coated tablets of glycyrrhetinic acid and hydroxypropyl-beta-cyclodextrin (GTA-HP-beta-CYD) inclusion complex tablets for colon-specific release.</p><p><b>METHOD</b>In order to improve the solubility of GTA, the GTA-HP-beta-CYD inclusion complex was prepared by ultrasonic-lyophilization technique and its formation were characterized by X-ray powder diffraction profiles and infrared spectrometry. The effects of inclusion condition on the inclusion efficiency and stability coefficient of inclusion complex were investigated, respectively. After prepared GTA-HP-beta-CYD tablets by powder direct compression, the pH dependant polymer Eudragit III and/or mixed with Eudragit II were used for further coating materials in fluid-bed coater. The influences of coating weight on the GTA release in different pH conditions were evaluated to establish the method for prepering colon specific delivery tablets with pulsed release properties.</p><p><b>RESULT</b>The formation of inclusion complexes were proved by X-ray powder diffraction profile and phase solubility curve. The effect of pH value of solvent was played critical role on the preparation of GTA- HP-beta-CYD inclusion complex. And the inclusion efficiency of GTA was 9. 3% and the solubility was increased to 54. 6 times at optimized method. The Eudragit III coated GTA- HP-beta-CYD tablets with coating weight 10% and 16% were showed pH dependant colon specific release profiles with slow release rate. The release profile of tablets coated with the mixture of Eudragit II and Eudragit III (1:2) were indicated typical pH dependant colon specific and pulsed release properties while the coating weight was 17%.</p><p><b>CONCLUSION</b>The preliminary method for preparation of colon specific release tablets containing glycyrrhetinic acid with improved solubility was established for further in vivo therapeutic experiment.</p>

Preparation and in vitro evaluation of gastroretentive dosage form containing puerarin-HP-beta-CD inclusion complex / 中国中药杂志

<p><b>OBJECTIVE</b>To prepare a novel floating micropellets containing hydroxy propyl-beta-oyclodextrin(puerarin-HP-beta-CD) for gastroretentive dosage form and evaluate its pharmaceutical characteristics in vitro.</p><p><b>METHOD</b>The puerarin HP-beta-cyclodextrin inclusion complex was prepared by freeze-drying method. Puerarin and its HP-beta-CD inclusion complex were incorporated into alginate beads, respectively. The effect of methyl cellulose (MC), Mg-Stearate and chitosan on buoyancy and cumulative release rate of puerarin were investigated in simulated gastric fluid.</p><p><b>RESULT</b>The spectrums of FTIR and profiles of X-ray powder diffraction of samples proved the formation of inclusion complex between puerarin and HP-beta-CD. Magnesium stearate had a significant effect on the buoyancy of micropellets, and satisfied results were gained by the content with 2%. The solubility of puerarin was increased 65.6-fold by the formation of inclusion complex, the dissolution rate and cumulative release percentage also improved significantly although with the burst release phenomena. The micropellets showed sustained release properties by using puerarin-HP-beta-CD inclusion complex mixed with puerarin (1:1) and treated thoroughly under homogenizer.</p><p><b>CONCLUSION</b>The solubility and release rate of puerarin are increased by the formation of inclusion complex with HP-beta-CD and its gastroretentive dosage forms displayed satisfied floating and sustained release characteristics.</p>

Separation and purification of active fraction with macroporous resigns / 中成药

AIM: To purify the water-extract of Sinisa recipe with macoroporous resigns. METHODS: Screening the purification condition by means of the content of active principle, fingerprint chromatography, the yield of dry extracts,et al. of the purified product. RESULTS: The purified product by type HP20 macoroporous resign is in good agreement with the active fraction of Sinisa in the composition of specific principles. CONCLUSION: HP20 type macoroporos resign is considered as optimum for active fraction of Sinisa recipe in purifying efficience.