DEVELOPMENT AND CHARACTERIZATION OF MICROSPONGE GEL FOR TOPICAL DELIVERY OF OREGANO OIL

Oregano oil is an essential oil possessing anti-inflammatory, antioxidant, antimicrobial, and immune-boosting properties that can be used in the treatment of various skin disorders. However, its practical applications are limited due to its handling issues and poor stability in the presence of air, light, and high temperature. To overcome these problems, this study aims to entrap oregano essential oil (OEO) in ethyl cellulose (EC) microsponges to get decreased dermal toxicity and enhanced stability. The quasi emulsion solvent diffusion method was utilized for fabrication of the OEO microsponges using EC as polymer, dichloromethane (DCM) as a solvent and polyvinyl alcohol (PVA) as stabilizer. The effect of formulation variables like stirring rate, stirring time and quantity of polymer were also examined. The prepared microsponges were evaluated for particle size and production yield. Results revealed that all microformulations were in the micro size range (19.87 mm to 248.13 mm), with a good production yield (72.85%) of M6. Spherical uniform shape with a spongy structure of microsponges was confirmed by Scanning Electron Microscopy (SEM). The optimized batch of OEO microsponges was further formulated into a gel and evaluated for physical appearance, pH, spreadability, viscosity and in-vitro release. Antimicrobial activity was also performed using E. coli, which indicates that the formulated microgel is safe (on dermal cells) than pure OEO and also confirmed their increased antibacterial effect. Moreover, stability analysis indicated enhanced stability of OEO microsponge gel. Hence, this essential oil became more stable, safe along with better handling due to entrapment in microsponges leading to an efficacious carrier system.