Formulation and Evaluation of Apremilast Co-Crystals Loaded in Gel

Abstract

Apremilast has low solubility and irritant effect in GIT can cause ulcerative colitis with bleeding. In this study, pharmaceutical cocrystals were designed to efficiently deliver Apremilast (APR) by topical administration to overcome this issue. Cocrystallization of drug with conformer is an immense approach used to explore the physicochemical properties of drug. Formulation and evaluation of APR co-crystals by solvent evaporation method for solubility enhancement were the objective of the current research. All the prepared formulations were evaluated by powder Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), dissolution, and solubility studies. Dissolution and solubility studies of the formulations confirmed that solubility enhanced as compared to the solubility of the available market drugs. From all these studies, it can be concluded that the co-crystallization technique enhanced the solubility of APR by using the solvent evaporation method. The cocrystals of APR were prepared in 1:1 molar ratio with urea. APR cocrystals showed the improvement in solubility and dissolution as compared to pure APR. The formation of cocrystals was confirmed from change in endothermic peak of DSC and from shifting of FTIR spectra of cocrystals. The topical gel of APR cocrystals was formulated using Carbapol-940 and hydroxypropyl methylcellulose (HPMC) as a gelling agent. The cocrystals with altered physicochemical properties of APR were prepared with Urea and formulated as a topical gel to overcome the problems related to oral administration. F2 formulation was found to be optimized batch and selected variables show a significant effect on the responses that are drug release and spread ability.