Engineering Long-Acting apixaban loaded PLGA microspheres for the treatment of stroke caused by atrial fibrillation

Atrial fibrillation needs effective anticoagulation strategies because it significantly increases the risk of stroke and is the leading cause of death in adults. Apixaban – a direct FXa inhibitor poses challenges in the form of poor patient compliance and dosing errors when administered via tablets, thus necessitates a novel delivery system. Conventionally, PLGA 50/50 results in immediate release profile compared to PLGA 75/25. We hypothesized the strong hydrogen bonding between apixaban and PLGA 50/50 through simulation and proved the transformation from immediate release to long-acting release of PLGA 50/50. The present study investigated the long-acting microsphere formulation of Apixaban for stroke prevention, using a microfluidic technology-integrated S/O/W double emulsion-solvent evaporation method. The fabricated formulations in terms of Apixaban-Ms (low, medium, and high) were optimized through the single factor investigation and orthogonal experimental design, and then produced on a large scale that exhibited round and smooth surface morphology. The molecular simulations indicated sustained release mechanisms for the proposed microsphere system, which was investigated for the first time, while DSC/XRD results confirmed the drug loading into microspheres in crystal form with modified thermal properties. Furthermore, the safety and biocompatibility study of the proposed microspheres was conducted using HUVEC cell line and was found safe and biocompatible. Notably, from a pharmacological perspective the pharmacokinetic studies in the in vivo model showed prolong release profile, while both in vitro and in vivo pharmacodynamic studies of fabricated formulation showed long-lasting anticoagulant activity through FXa level reduction and enhanced APTT and PT levels. These findings in a nutshell, suggest into valuable insights of Apixaban-loaded long-acting microspheres for the clinical application in stroke prevention among patients suffering from atrial fibrillation.