Enhancement of Solubility and Dissolution Rate of Poorly Soluble Drug Nifedipine by Solid Sedds

Abstract

Nifedipine is a dihydropyridine calci channel blocking agent belongs to biopharmaceutical classification system (BCS) class-II mainly applied in the treatment of hypertension and angina-pectoris. The objective of this work is to improve the solubility and dissolution rate of nifedipine by formulating into a solid-self micro emulsifying drug delivery system (solid smedds). Methods: Oil, Surfactant, and cosurfactant were selected by solubility screening study. For the determination of the best emulsion region, a pseudo ternary diagram was prepared. Based on solubility castor oil, tween 80 and polyethylene glycol (PEG) 400 was selected in which SCOSmix (a mixture of surfactant and cosurfactant) was 1:1. Thermodynamic stability study was performed for the determination of stable smedds formulation. These formulations were evaluated for self emulsification time, drug content analysis, robustness to dilution test, particle size analysis, and in vitro diffusion study. The optimized formulation was selected for formulating into solid-smedds by using aerosil 200 at a different ratio. SCF9L (0.65:1) was selected due to its good flow property. Then it was evaluated for particle size analysis, drug content study, differential scanning calorimetry (DSC), X-Ray Diffraction study (XRD), fourier transform infrared spectroscopy (FTIR) Scanning Electron Microscopy study (SEM) analysis, and in vitro dissolution study. Results: DSC and XRD result shows that the drug within the formulation was in the amorphous state. From the SEM analysis, the texture of powder showed a uniform granular structure, and there was no incompatibility between drugs. Excipients was observed from ftir study. From the in vitro dissolution study, it improved the dissolution rate of nifedipine, which was 98.68% of drug release, where pure drug release only 6.75%.