Palmitic Acid Grafted Maize Starch (PAgMS) Nanoparticles as Potential Drug Carrier for Irbesarten: In Vitro and In Vivo Evaluation

Background: Irbesarten antagonizes angiotensin II by blocking AT1 receptors in hypertension. Objective: To develop hydrophobically modified starch nanoparticles and to increase the dissolution and bioavailability of Irbesarten. Methods: The synthesis of palmitic acid grafted maize starch (PAgMS) using long chain fatty acid was performed by esterification. The formation of palmitic acid grafted maize starch (PAgMS) was confirmed by FTIR and NMR study. Particle size measurements, zeta potential, percentage drug entrapment efficiency were characterized to optimize formulations. Results: The particle size of formulation shows smaller particle size and high drug entrapment efficiency. All formulations showed negative zeta potential which results in better stabilization of the nanoparticles. The Scanning electron microscopy (SEM) results revealed that Irbesarten was present in amorphous state in the polymer. There was a significant enhancement of in vitro release (94.75%) of Irbesarten from PAgMS nanoparticles as compared to pure Irbesarten (20%) in 60 min. Irbesarten loaded palmitic acid grafted maize starch (PAgMS) nanoparticles showed significant increase (P<0.001) in relative bioavailability than marketed formulation. Conclusion: In conclusion, the prepared Irbesartan loaded palmitic acid grafted maize starch (PAgMS) nanoparticles showed remarkable increase in dissolution rate and hence bioavailability in rabbit.