Development of novel prasugrel base microsphere-loaded tablet with enhanced stability: Physicochemical characterization and in vivo evaluation in beagle dogs.

The objective of this study was to develop a novel prasugrel base microsphere-loaded tablet (PBMST) with enhanced stability as a bioequivalent to the commercial prasugrel hydrochloride-loaded tablet. Numerous prasugrel base-loaded microspheres were prepared with hydroxypropylmethyl cellulose (HPMC), colloidal silica and various acidifying agents using a spray-drying process, and the physicochemical properties, solubility and stability were investigated. The PBMSTs were prepared and their dissolution, pharmacokinetics in beagle dogs and stability were evaluated compared to commercial prasugrel hydrochloride-loaded tablets. Among the acidifying agents tested, phosphoric acid provided the greatest increase in drug solubility, by as much as 110-fold. The prasugrel base-loaded microspheres composed of prasugrel base, HPMC, colloidal silica and phosphoric acid at a weight ratio of 10/10/5/2.5 provided an amorphous drug and reduced particle size of about 11.3μm. Moreover, it exhibited excellent solubility and improved stability compared to prasugrel base and hydrochloride. Moreover, PBMST drug dissolution was improved in comparison to the prasugrel base-loaded tablet (PBT), with similar dissolution to the commercial prasugrel hydrochloride-loaded tablet at pH 1.2 and 4.0. PBMST provided significantly higher plasma concentrations of AUC and Cmax in beagle dogs compared to PBT. In particular, the AUC of PBMST was approximately four times greater than PBT, leading to improved oral bioavailability. There were no significant differences observed for all pharmacokinetic parameters between PBMST and the commercial prasugrel hydrochloride-loaded tablet, suggesting their bioequivalence in beagle dogs. Furthermore, the prepared PBMSTs were stable for at least six months. Therefore, this novel prasugrel base microsphere-loaded tablet could be a potential alternative for enhancing the stability and bioavailability of prasugrel.