Investigation of Dissolution Enhancement of Nifedipine by Deposition on Superdisintegrants

In this study we aimed to investigate the dissolution enhancement of nifedipine by the solvent deposition technique using superdisintegrants including Ac-Di-Sol, Kollldon CL, and Explotab as excipients. The relative significance of action of solvent deposition (deposition of small drug particles on the excipient after solvent is evaporated) and action of superdislntegrant was investigated. The effect of solvent on dissolution of nifedipine in the solvent deposition system was also Investigated. Differential scanning calorlmetry (DSC) was used to study the interaction between nifedipine and superdisintegrants. Capsules and tablets of a physical mixture and a solvent deposition system of nifedipine were prepared. The dissolution rate of nifedipine of these capsules and tablets was studied. The results of this study show that solvent deposition system with lactose and super dlslntegrants in capsule and tablet dosage forms can significantly enhance dissolution rate of nifedipine. Both the action of superdislntegrant and solvent deposition contribute to the enhancement of the dissolution, but the solvent deposition is mainly responsible for this enhancement. The solvent and disintegrants used can influence the dissolution rate also. The solvent deposition system using both Kollldon CL as excipient and dichloromethane as solvent has the highest dissolution rate. DSC study indicated Kollldon CL has the strongest interaction with nifedipine also.