Studies on enhancement of solubility and dissolution properties of Nimodipine by solid dispersion technique

Abstract

Nimodipine, a member of calcium channel blocker, specifically binds to L-type voltage-gated calcium channels. The maximum solubility of nimodipine was found at pH 1.2 and solubility decreases up to pH 4.0. At a pH 6.0 and higher pH, solubility reduces drastically. Suitable solid dispersion systems of nimodipine with PVP-K30 and maltodextrin were prepared by physical mixture, solvent evaporation and kneading methods at 1:1 and 1:3 drug: carrier. Drug content, saturation solubility, FTIR, and in-vitro dissolution were studied. The drug content was uniform, solubility of the drug increased linearly as a function of the carrier concentration and method. The FTIR studies indicates no chemical interaction between drug and polymer. The DP60 and DE60 values of solid dispersion systems prepared by solvent evaporation and kneading method were significantly higher (P<0.05) when compared to DP60 and DE60 values of physical mixture and pure Nimodipine. The dissolution follows first order model and obeyed Hixson- Crowell’s cube root law.