Preparation of a topical form of melatonin using lipid carriers and investigation of their physicochemical properties

Abstract

Introduction: Melatonin is a naturally occurring compound found in both plants and animals, and in humans, it is secreted by the pineal gland during the night. This hormone plays a key role in regulating the sleep-wake cycle, and its antioxidant, anti-inflammatory, and sleep-promoting properties have been demonstrated in various studies. However, oral administration of melatonin is associated with certain limitations, including a short half-life and significant first-pass hepatic metabolism, which reduce its efficacy. An effective approach to overcome these challenges is the use of topical drug delivery systems, such as lipid-based vesicles.Aim: The aim of this study is to formulate melatonin-loaded lipid vesicles using niosome and transfersome methods and to investigate the physicochemical properties of the formulations prepared by these two techniques.Methodes: Melatonin-loaded lipid vesicles were prepared using the thin-film hydration method, a well-established and effective technique for developing lipid-based delivery systems that allows control over particle size and drug loading. Following the formulation, physicochemical properties—including particle size, zeta potential, vesicle morphology (using electron microscopy), drug loading efficiency, and release profile—were evaluated. These analyses were conducted to compare the efficacy and stability of the two types of vesicles (niosomes and transfersomes) and to identify the most suitable formulation for topical delivery of melatonin.Results: In the particle size distribution analysis using Dynamic Light Scattering (DLS), the average size of the nanovesicles was approximately 305 nm for niosomes and around 205 nm for elastic liposomes. Additionally, the zeta potential was measured to be about –30 mV for niosomes and –10 mV for elastic liposomes. In the drug release study, results showed that over a 24-hour period, approximately 47% of the drug was released from the niosomes, whereas about 60% was released from the elastic liposomes. The morphology of the synthesized nanoparticles was also examined using Scanning Electron Microscopy (SEM). Drug loading efficiency was calculated to be 66.79% for niosomes and 54.75% for elastic liposomes.Discussion: This study resulted in the production of nanoparticles with acceptable size and drug loading efficiency. In terms of certain physicochemical properties- such as more controlled drug release, improved stability, and higher drug loading efficiency- niosomes demonstrated superior performance compared to elastic liposomes. These characteristics make niosomes more suitable for the intended purpose of delivering adequate amounts of the drug topically to the target site.