Development of a Liposomal Gel for Prolonged Ophthalmic Soluble Drug Delivery

Abstract

AbstractLiposome, as a drug delivery vehicle, entraps drugs, releases them sustainably, and modifies release patterns. This entrapment has diminished exposure of the drug to the eye medium, which could minimize adverse effects. In this investigation, 18 formulations in 3 key categories (liposome, gel and lipogel) of cromolyn sodium (CS) were prepared and evaluated as a water‐soluble drug. Then, liposome formulations (L1‐L6) were developed using the thin‐film hydration method. The macroscopic and microscopic assessments comprised drug entrapment efficiency, release rate, release mechanism, liposome stability, and vesicle size were evaluated to evaluate liposomes and lipogel. The results revealed that applying cholesterol in formulations ranging from 33 % to 44 % w/w increased the liposome drug entrapment efficiency, stability, and release time. The optimum phosphatidylcholine (PC) ratio to cholesterol in the L4 formulation was 2 : 1, which prolonged drug release time by up to 5 hours. The carbomer® 934 containing lipogel (0.5 % w/v) showed the longest release time (9 hours) with a zero‐order release. CS release from HPMC (2 % w/v) lipogel was assumed to follow first‐order release kinetics. The prolongation of drug release time in a carboxymethylcellulose lipogels was shorter than carbomer® 934 (5 hours). Finally, a sustained release formulation of CS liposome was produced; it was developed as lipogels to enhance its release duration; finally, release kinetic were modified.