HPMC as a potential enhancer of nimodipine biopharmaceutical properties via ball-milled solid dispersions

Highlights

• Amorphous ball-milled solid dispersions of nimodipine and HPMC were developed.

• HPMC solid dispersions enhanced the biopharmaceutical properties of the drug.

• Hydrogen bonding was established between nimodipine and HPMC.

• HPMC stabilizes solid dispersions through a dilution mechanism.

Abstract

The poor solubility of drugs remains one of the most challenging aspects of formulation development. Aiming at improving the biopharmaceutical limitations of the calcium channel blocker nimodipine, the development of solid dispersions is proposed herein. Three different proportions of nimodipine:HPMC were tested and all of them generated amorphous solid dispersions. Improvements of up 318% in the solubility and a 4-fold increase in the dissolution rate of nimodipine were achieved. Stability studies conducted over 90 days in a desiccator indicated that the initial characteristic of the formulations were maintained. However, at 40 °C/75% RH recrystallization was observed for solid dispersions with 70 and 80% of HPMC, whilst the formulation composed of 90% of the carrier remained amorphous. The increase in the stability observed when the HPMC concentration was increased from 70 to 90% in the solid dispersions was attributed to the dilution mechanism.