In Vitro Evaluation of Niosomal Formulation for Controlled Delivery of 4‐Hydroxyisoleucine

Abstract The development of drug delivery systems has aimed to improve bioavailability and reduce limitations of traditional dosing schedules. Vesicular systems like niosomes have gained importance for their stability, cost‐effectiveness, and controlled release capabilities. Niosomes can encapsulate both hydrophobic and hydrophilic drugs, making them versatile carriers for various therapeutic agents. Recent research focuses on enhancing niosomes for targeted drug delivery, such as incorporating 4‐hydroxyisoleucine (4‐HIL) for diabetes treatment. In this study, 4‐HIL from fenugreek seeds was encapsulated in niosomes and PEGylated niosomes using a thin‐film hydration method. The 4‐HIL‐loaded niosomes showed semi‐spherical, smooth structures with a size of 200 nm, zeta potential of ‐22 mV, and entrapment efficiency ranging from 55.1% to 87.1%. FTIR spectroscopy confirmed hydrogen bonding between span 60 and cholesterol in the niosomal formulation. PEGylation increased vesicle size to 460–580 nm and enhanced encapsulation efficiency to 75.43–90.1%. The PEGylated niosomes significantly suppressed the in vitro release of 4‐HIL, making this formulation a promising drug delivery system for sustained release of anti‐diabetic drugs.