Proliposomes: Cutting-Edge Carrier System for Enhanced Drug Delivery

Proliposomes represent a promising, advanced platform for lipid-based drug delivery systems, developed to overcome the limitations of conventional liposomes, particularly their physical instability, short shelf life, and high production costs. Proliposomes are defined as dry, free-flowing granular or powdered formulations composed of phospholipids and pharmacologically active agents, which spontaneously form liposomal dispersions upon hydration. Their solidstate nature offers distinct advantages in terms of storage stability, ease of transport, and scalability in industrial manufacturing. This review provides a comprehensive overview of proliposomes, covering their formulation strategies, key excipients (e.g., cholesterol and carriers such as mannitol and sorbitol), and modern preparation techniques, including film deposition, spray drying, and fluidized-bed coating. Mechanisms of vesicle formation, drug encapsulation, and release behaviour are discussed in the context of physicochemical interactions and thermodynamic transitions during hydration. In addition to discussing analytical characterization methods (e.g., particle size analysis, zeta potential, encapsulation efficiency, morphological imaging), the review explores the therapeutic applications of proliposomes across a range of clinical conditions. The paper also addresses regulatory considerations, stability testing protocols (e.g., ICH Q1A guidelines), and the suitability of USP Apparatus 4 for dissolution testing of proliposomal products. By integrating recent findings and technological advancements, this review highlights the potential of proliposomes as a versatile, industrially viable alternative to conventional liposomes for modern drug delivery.