Taste-Masked Pellets of Warfarin Sodium: Formulation towards the Dose Personalisation

The bitter drug, warfarin, has a narrow therapeutic index (NTI) and is used in paediatrics and geriatrics. The aim of this feasibility study was to formulate the taste-masked warfarin-containing pellets to be applicable for dose personalisation and to improve patient compliance, as well as to investigate the effect of the core type (PharSQ^® Spheres M, CELPHERE™ CP-507, and NaCl) on the warfarin release from the Kollicoat^® Smartseal taste-masking-coated pellets. The cores were successfully drug-loaded and coated in a fluid-bed coater with a Wurster insert. An increase in particle size and particle size distribution was observed by optical microscopy. In saliva-simulated pH, at the Kollicoat^® Smartseal level of 2 mg/cm², none of the pellets demonstrated drug release, confirming their efficient taste-masking. However, in a stomach-simulated pH, a faster drug release was observed from PharSQ^® Spheres M- and CELPHERE™ CP-507-coated pellets in comparison with NaCl cores. Additional experiments allowed us to explain the slower drug release from NaCl-containing pellets because of the salting-out effect. Despite the successful taste masking, the drug release from pellets was relatively slow (not more than 91% per 60 min), allowing for further formulation improvements.