Preparation and characterization of niosomes for the delivery of a lipophilic model drug: comparative stability study with liposomes against phospholipase-A 2

Vesicular nanocarriers like niosomes and liposomes are widely researched for controlled drug delivery systems, with niosomes emerging as promising alternatives due to their higher stability and ease of manufacturing. This study aimed to develop and characterize a niosomal formulation for the encapsulation and sustained release of temozolomide (TMZ), a model lipophilic drug, and to compare the stability of niosomes and liposomes, with a particular focus on the behavior of their lipid bilayers. Niosomes were prepared using the thin-film hydration method, composed of Span 60 (Sorbitan monostearate), cholesterol, and soy lecithin in varying molar ratios. The study investigated critical properties such as drug loading capacity, release kinetics, and resistance to enzymatic degradation. The optimized formulation was analyzed for drug entrapment efficiency and stability against phospholipase A