Inclusion complex of aprepitant with cyclodextrin: evaluation of physico-chemical and pharmacokinetic properties

Aprepitant (APR) is a water insoluble drug approved for the treatment of chemotherapy induced nausea and vomiting (CINV) and post-operative nausea and vomiting (PONV). The innovator Emend® is a formulation incorporating drug nanoparticles with good bioavailability (~67%). The objective of the current work was to evaluate the feasibility of formulating a cyclodextrin complex of APR with enhanced solubility/dissolution rate and concomitantly bioavailability.

The complex was prepared using two approaches: kneading and slurry method. The formulated complex was evaluated using DSC, XRPD and FT-IR studies.

DSC, XRPD and FT-IR studies confirmed the interaction of β-cyclodextrin with APR indicating formation of a true complex wherein the drug was encapsulated in the cyclodextrin cavity (inclusion phenomenon). In addition to inclusion complexation, non inclusion phenomenon viz., interaction among hydroxyl groups of cyclodextrin and APR was also observed. The saturation solubility and dissolution rate of drug complex was higher than that of aprepitant API. The rate (C(max)) and extent of absorption (AUC) of APR from the complex were found to be comparable to that of Emend® (Reference product).

These studies established that cyclodextrin complexation may provide another viable and cost effective option for enhancing solubility and bioavailability of APR.