Impact of Using Blended Polymers on the Structural and Functional Attributes of Eptifibatide-Loaded Microspheres

The saturation of generics has shifted the focus on developing technology-based delivery systems, not only for small molecules but also for proteins and peptides. Proteins and peptides require novel delivery systems as conventional delivery systems are of not much use. Biodegradable polymer-based microspheres have received considerable interest for the controlled delivery of many therapeutic proteins and peptides. Despite being known for many years, developing biodegradable polymer-based microspheres has remained a challenge. Among many challenges, selecting an appropriate grade of polymer is crucial. A right grade of polymer is required to achieve the desired physicochemical properties and mainly the release of the drug from the formulated microspheres. However, because of the limited number of companies supplying GMP-grade polymers, polymer selection has become a daunting task. The cost of these polymers is very high, and when a suitable grade of polymer is unavailable, customization is required, which further increases the cost. To address this critical issue, this research focused on comparing Eptifibatide-loaded microspheres formulated using blending polymers vs those formulated using original/on shelf polymers. Polymers R202H and RG502H were physically blended in different ratios to obtain blended polymers with different comonomer ratios. Specifically, polymers with closer IV values were used in this study. The microspheres formulated using blended polymers were compared with those formulated using original/on-shelf polymers, and both sets demonstrated identical performance.