Dissolution enhancement of felodipine by amorphous nanodispersions using an amphiphilic polymer: insight into the role of drug-polymer interactions on drug dissolution.

Context: Felodipine, a poorly soluble drug, is widely used in the treatment of angina pectoris and hypertension.

Objective: This study aimed at the preparation of amorphous solid dispersion (SD) of felodipine using an amphiphilic polymer, soluplus, for the potential enhancement in solubility of the drug.

Materials And Methods: Solid dispersions with varying proportions of drug and soluplus were prepared and the rate and extent of dissolution from SDs was compared with that of the pure drug. FT-IR and (1)H NMR spectroscopic analysis were carried out to examine the formation mechanism of SDs. Various techniques were used for solid state characterization of designed SDs.

Results: Formation of amorphous solid dispersions with particle size in nanometer range indicated suitability of polymer and method used in the preparation. FT-IR and (1)H NMR spectroscopy revealed that soluplus was involved in strong hydrogen bonding with felodipine molecules which resulted in the conversion of crystalline felodipine into amorphous form. Solid dispersion with 1:10 drug/polymer ratio showed more than 90% drug dissolution in 30 min whereas pure felodipine showed less than 19% drug dissolution in 1 h.

Discussion And Conclusion: Amorphous SDs of felodipine were prepared using soluplus resulting in substantial enhancement in the rate and extent of dissolution of felodipine.