Encapsulation of babchi essential oil into microsponges: Physicochemical properties, cytotoxic evaluation and anti-microbial activity

Babchi essential oil (BEO) is a valuable essential oil reported to possess a variety of biological activities such as antitumor, anti inflammatory, immunomodulatory, antioxidant, antifungal and antibacterial properties. Due to its anti-microbial properties, this oil possesses an immense potential for the treatment of dermatological disorders. Further, it has minimal tendency to develop resistance, a common issue with most of the antibiotics. However, its highly viscous nature and poor stability in the presence of light, air and high temperature, limits its practical applications. To surmount these issues, this research aims to encapsulate BEO in ethyl cellulose (EC) microsponges for enhanced stability, antibacterial effect and decreased dermal toxicity. The quasi emulsion solvent evaporation technique was used for fabrication of the BEO microsponges employing EC as polymer, polyvinyl alcohol (PVA) as stabilizer and dichloro methane (DCM) as solvent. The effect of formulation variables such as the amount of EC and PVA were also investigated. The prepared microformulations were evaluated for production yield, encapsulation efficiency, particle size and in vitro release. In vitro cytotoxicity was also checked to assess dermal safety of BEO microsponges. Results revealed that all the dispersions were in micro size range (20.44 ± 3.13 μm to 41.75 ± 3.65 μm), with good encapsulation efficiency (87.70 ± 1.20% of F2) and controlled release profile (cumulative drug release 73.34 ± 1.76%). Field emission scanning electron microscopy results showed that the microsponges possessed a spherical uniform shape with a spongy structure. Results of cytotoxicity study indicated that the prepared microsponges were safer on dermal cells in comparison to pure BEO. The optimized formulation was also evaluated for in vitro antimicrobial assay against dermal bacteria like Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, which confirmed their enhanced antibacterial activity. Furthermore, the results of photostability and stability analysis indicated improved stability of BEO loaded microsponges. Hence, encapsulation of BEO in microsponges resulted in efficacious carrier system in terms of stability as well as safety of this essential oil alongwith handling benefits. Keywords: Essential oil, Ethyl cellulose, Photostability, Cytotoxicity, Anti-microbial activity