Potential Assessment of Topical Felbinac-Loaded Cubosomal Gel in Soft Tissue Injury in Albino Rats.

Muscle strain is one of the most common injuries with high intermittence rate. Due to diverseness of strain injuries, different experimental animal models are employed to investigate such injuries with reproducible results. Cubosomes, an emerging nano drug delivery tool, are considered ideal carriers for the topical delivery of lipophilic drugs to treat local inflammations with reduced frequency of application for prolonged periods. This work describes the development of Felbinac-loaded cubosomal gel and investigated the treatment of inflammation and tissue injury in vivo. Sciatic Function Index (SFI) is a simple clinical method to observe hind limb recovery in rats after induced injuries. First, cubosomes were fabricated by high-pressure homogenization process and evaluated for in vitro parameters. The optimized cubosome formulation was chosen to develop cubosomal gel and evaluated for in vitro parameters and also investigated time to recovery of SFI after strain induction in tibialis anterior muscles in rats. The cubosome formulation (F4) exhibited low droplet size (51.04 ± 1.37 nm)and polydispersity index (0.085 ± 1.13), and negative zeta potential (-32.8 ± 0.67 mV). In rats, topical application of cubosomal gel formulation (CGF) exhibited significant improvement in skin permeation (402 ± 6.08 μg) and drug flux (15.71 ± 0.82 μg/cm² h) compared to plain gel. Also, CGF demonstrated significant difference in SFI from first to seventh day. The histology of rat skin showed significant effect for groups treated with Felbinac-loaded CGF compared to a negative control group.