Studies of preparation, characterization, and solubility of mefenamic acid-nicotinamide co-crystal synthesized by using melt crystallization method

Objective : The objective of this study is to develop the formation mefenamic acid (MFA) – nicotinamide (NCT) co-crystal by using melt crystallization method and investigate its solubility.Method : Co-crystal was prepared by using melt crystallization method of MFA-NCT (1:2) at (220±3) ° C. The initial co-crystal formation was performed by powder x-ray diffraction (PXRD). The thin layer chromatography (TLC) method was done to confirm the chemical stability of MFA and NCT due to synthesized process. The melt crystallization of MFA-NCT (1:2) was characterized by DSC/TG, Infrared spectrophotometry, and scanning electron microscopy. The solubility of the melt crystallization of MFA-NCT (1:2) was evaluated by incubated the samples in water at 25 °C and shaken for 24 h. The solubility of MFA was measured by UV-Vis spectrophotometer.Result : Characterizations of a co-crystal MFA-NCT (1:2) including PXRD, FTIR, DSC and SEM have indicated the formation of new solid crystal phase that differ from MFA, NCT and its physical mixture. The chromatogram of the TLC study exhibited two spot that corresponds to MFA and NCT. The solubility of the melt crystallization of MFA-NCT (1:2) was 57.97 % higher than MFA solubility.Conclusion : These results suggest that MFA-NCT co-crystal can be synthesized by using melt crystallization method without decomposition of its component and provides an opportunity for the development of MFA solid form.Keywords: co-crystal, mefenamic acid, nicotinamide, melt crystallization, solubility