ENCAPSULATION OF EXEMESTANE WITH β-CYCLODEXTRIN AND TERNARY AGENT: FORMULATION, EVALUATION AND ANTICANCER ACTIVITY

Abstract

Objective: A potent aromatase inhibitor, Exemestane, is well known for its anticancer action in breast neoplasm. The vital problem of this medicament is its poor aqueous solubility, which hinders its dissolution in body fluids. Therefore, the present study targets to enhance the water solubility of Exemestane by means of its complexation with β-cyclodextrin and a suitable ternary agent. Methods: Inclusion complexes of Exemestane with β-cyclodextrin and ternary agent were prepared by kneading and lyophilization technique. Different hydrophilic polymers and organic acids were screened for their influential ability as a co-complex with a carrier; β-cyclodextrin. The validation of complex formation was carried out by various solid-state techniques. The geometry of Exemestane in the β-cyclodextrin cavity was picturized in docking studies. The in vitro anticancer activity of prepared inclusion complex formulations carried out using MCF-7 cell lines Results: Phase solubility analysis proved HPMC E5 as the best ternary agent for complexation of Exemestane with β-cyclodextrin as it improved the stability constant of the drug from 665.92 M-1 to 1238.38 M-1. The synthesized binary and ternary inclusion complexes exhibited 2.74 and 4.62 times enhanced solubilization of Exemestane. Likewise, the dissolution characteristics of Exemestane were improved, and drug release was increased by 1.18 and 1.42 times with binary and ternary freeze-dried formulations. Differential scanning calorimetry (DSC) and powder X-ray diffractometry (PXRD) study results presented the formation of binary and ternary complexes with significantly drooped crystallinity. Docking studies predicted encapsulation of rings A, B, and C of Exemestane in the cavity of β-cyclodextrin. In-line results were obtained in Fourier transform infrared (FTIR) studies. The cell growth inhibition of 62.78 % was achieved with a ternary complex of Exemestane which was far superior than the pure active moiety that showed mere 44.56 % of inhibition. Conclusion: Altogether, it can be concluded that the inclusion complex of Exemestane boosted its aqueous solubility, resulting in its increased dissolution and in vitro anticancer activity in a breast cancer MCF-7 cell line.