• Journal of Pharmaceutical Investigation
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• v.40 no.1
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• pp.9-14
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• 2010

Lacidipine used for the treatment of hypertension has low water solubility and is classified as BCS Class II category. Gelucire-based solid dispersions (SD) containing lacidipine were prepared by solvent evaporation method to enhance drug dissolution. The powdered forms of SD showed irregularly spherical shape. Thermal behaviors of SD from differential scanning calorimetry indicated that distinct endothermic peak of lacidipine ($184^{\circ}C$) was shifted to lower region ($150.1^{\circ}C$). Drug was present in a crystalline form. NMR spectra also showed some molecular interaction between drug and Gelucire. There was no significant difference in DSC and NMR behaviors between Gelucire 44/14 and Gelucire 50/13. The initial dissolution rate of SD-loaded tablet linearly increased both in water and in water containing 1% tween 20, and much higher than the commercial tablet, $Vaxar^{(R)}$. When the amount of SD was increased, the release rate was greater. The Gelucire 50/13 showed higher dissolution than the Gelucire 44/14. The produced solid dispersion with various kinds of excipients and making tablets, it was found that solid dispersions can increase the solubility in artificial gastric juice and finally increases dissolution rate.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.1939-1943
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• 2014

Solid dispersion (SD) system of everolimus (EVR) with Gelucire 50/13 (Stearoyl polyoxyl-32 glycerides) was prepared using melt granulation technique with the aim of improving the physicochemical properties and dissolution rate. The solid state characterization using scanning electron microscopy and X-ray powder diffraction, indicated that the drug was homogeneously distributed in the surfactant carrier in a stable amorphous form. The dissolution rate of EVR from the optimized SD composed of the drug, Gelucire 50/13 and microcrystalline cellulose in a weight ratio of 1:5:10, was markedly rapid and higher than that from the drug powder and the market product (Afinitor$^{(R)}$, Novartis Pharmaceuticals) in all dissolution mediums tested from pH 3.0 to pH 6.8. The results of this study suggest that formulation of SD with Gelucire 50/13 using melt granulation procedure may be a simple and promising approach for improving the dissolution rate and oral absorption of the anti-cancer agent without the need for using an organic solvent.

• Journal of Pharmaceutical Investigation
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• v.41 no.4
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• pp.239-247
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• 2011

Simvastatin is an inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which catalyzes the conversion of HMG-CoA to mevalonate, an early and rate-limiting step in the biosynthesis of cholesterol. Simvastatin has good permeability, but it also has low solubility (BCS class II), which reduces its bioavailability. To overcome this problem, a solid dispersion is formed using a spray-dryer with polymeric material carrier to potentially enhance the dissolution rate and extend drug absorption. As carriers for solid dispersion, Gelucire$^{(R)}$44/14 and Gelucire$^{(R)}$ 50/13 are semisolid excipients that greatly improve the bioavailability of poorly-soluble drugs. To avoid any toxic effects of an organic solvent, we used aqueous medium to melt Tween$^{(R)}$ 80 and distilled water. The structural behaviors of the raw materials and the solid dispersion were analyzed by differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). The DSC and PXRD data indicated that the crystalline structure of simvastatin was transformed to an amorphous structure through solid dispersion. Then, solid dispersion-based tablets containing 20 mg simvastatin were prepared with excipients. Dissolution tests were performed in distilled water and artificial intestinal fluid using the USP paddle II method. Compared with that of the commercial tablet (Zocor$^{(R)}$ 20 mg), the release of simvastatin from solid dispersion based-tablet was more efficient. Although the stability study is not complete, this solid dispersion system is expected to deliver poorly water-soluble drugs with enhanced bioavailability and less toxicity.