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

Abstract

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 ¹H 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 ¹H 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.

• Amorphous
• Fourier transform-infrared spectroscopy
• ¹H NMR
• high-performance liquid chromatography
• hydrogen bonding
• solid dispersion

Acknowledgements

We are grateful to Prof. Subhasis Ghosh (School of Physical Science, Jawaharlal Nehru University, New Delhi, India) for extending AFM facilities to this work. We also acknowledge BASF (Mumbai, India) for providing gift samples of soluplus.

Declaration of interest

The authors declare no conflict of interest. We are thankful to University Grants Commission, India and Department of Science and Technology, India for providing financial support for this work.