Early formulation development of CKD-519, a new CETP inhibitor, for phase 1 clinical study based on in vitro and in vivo evaluation

CKD-519, a potent cholesteryl ester transfer protein (CETP) inhibitor, is a clinical candidate being developed for the treatment of dyslipidemia. It is considered a Biopharmaceutical Classification System II compound with low solubility and high permeability. The objective of this study was to develop early formulations focusing on the dissolution rate of the compound to achieve dose-dependent exposure. High performance formulation strategies including solid dispersion (SD) and a self-microemulsifying drug delivery system (SMEDDS) were investigated and their in vivo and in vitro correlations were also evaluated in monkeys along with dose optimization in human volunteers. The SD granules were prepared in a fluid bed granulator using microcrystalline cellulose and mannitol as carriers. Poloxamer 407 and Eudragit E PO were each found to be a suitable solubilizing agent and polymer for the improvement of the CKD-519 dissolution rate. Pharmacokinetic studies in monkeys showed that the SD tablets exhibited better absorption than the SMEDDS in a dose-dependent manner from 1.5 mg to 100 mg. The mannitol-based SD tablet formulations were bioequivalent. However, pharmacokinetics studies in humans showed that the dose was saturable above 100 mg of CKD-519. This study was performed to determine how to develop early formulations for clinical studies and to identify rational formulation development strategies for CKD-519 to establish the pharmaceutical proof-of-concept in humans.