Influence of polyvinyl pyrrolidone addition during crystallization on the physicochemical properties of mefenamic acid crystals

Abstract EN

Crystallization of mefenamic acid in the presence of polyvinyl pyrrolidone was carried out in an effort to improve its physicochemical properties.

Mefenamic crystals were prepared as follows: A supersaturated solution of mefenemic acid using absolute ethanol as a solvent was prepared.

Then an aqueous polymeric solution of polyvinyl pyrrolidone (PVP) was added, cooled, and filtered.

The concentration of the polymer varied as follows 0, 1, 5, 12.5, and 25%.

The collected crystal properties were tested using optical microscopy, differential scanning calorimetry (DSC), Fourier transform infra red spectroscopy (FTIR), and x-ray powder diffraction.

Solubility, dissolution, and wetability properties of the crystal were also evaluated.

A result showed that the crystallized samples were mainly composed of mixture of polymorph I and II and as the concentration of PVP increases proportions of Polymorph I in the mixture increases.

Enhancement of the dissolution rate was achieved in all crystallized samples and as the concentration of PVP was increased, dissolution rate increased.

The wetability of the formed crystal improved as the concentration of the PVP was increased.

Wetability results explained the improvement in dissolution rate despite the formation of large crystals mainly composed of the more stable polymorph (Form I).