Mefenamic acid, an anti-inflammatory drug, exhibits poor water solubility and flow properties, poor dissolution and poor wetting. Consequently, the aim of this study was to improve the dissolution of both the form of mefenamic acid (1 & II). Microspheres containing mefenamic acid (Form 1 & II) were produced by spray drying using isopropyl alcohol and water in the ratio of 40:60 (v/v) as solvent system. The prepared formulations were evaluated for in vitro dissolution and solubility. The prepared drug particles were characterized by scanning electron microscopy (SEM), differential scanning calorimeter (DSC), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Dissolution profile of the spray dried microspheres was compared with pure sample and recrystallized sample. Spray dried microspheres of both form of mefenamic acid exhibited decreased crystallinity and improved micromeritic & mechanical properties. The dissolution of the spray dried microspheres (Form 1 & II) were improved compared with recrystallized and pure sample of mefenamic acid. Consequently, it was believed that spray drying of mefenamic acid is a useful tool to improve dissolution, Hence this spray drying technique can be used for formulation of tablets of mefenamic acid by direct compression with directly compressible tablet excipients.

Keywords: Spray drying, Mefenamic acid, Form 1 & II, Solubility dissolution, Crystallinity.