In vitro-in vivo evaluation of tetrahydrozoline-loaded ocular in situ gels on rabbits for allergic conjunctivitis management.

Ocular allergy is one of the most common disorders of the eye surface. The conventional eye drops lack of therapeutic efficacy due to low ocular bioavailability and decreased drug residence time on eye surface. Hence, the present research work aimed to formulate, optimize, and evaluate the in situ gel for ophthalmic drug delivery. The prepared in situ gel formulations were evaluated for clarity, pH, gelling capacity, viscosity, osmolality, in vitro release study, and kinetic evaluation. ex vivo corneal permeation/penetration study using goat and in vivo studies on rabbits were also performed. Fourier-transformed infrared spectroscopy was also applied to study possible interactions between drug and polymers. The formulations found to be stable, nonirritant, and showed sustained release of the drug for a period of up to 24 hr with no ocular damage. The developed in situ gels loaded with tetrahydrozoline are alternative and promising ocular candidates for the treatment of allergic conjunctivitis.

Evaluation of burn wound healing activity of novel fusidic acid loaded microemulsion based gel in male Wistar albino rats.

The objective of the present research was to examine the possible usage of microemulsion based gel for fusidic acid (FA) dermal application as burn wound treatment. During the preparation of microemulsion, ethyl oleate as oil phase, tween 80 as a surfactant, ethanol as co-surfactant, water as aqueous phase were used. The prepared microemulsions were evaluated for clarity, pH, viscosity and FA content. Moreover, stability, sterility, antibacterial activity, in vitro release of the formulations were also evaluated. The results showed that the FA loaded microemulsion and microemulsion based gel formation and characteristics were related to many parameters of the components. The performed optimized microemulsion-based gel showed good stability over a period of 3 months. The antibacterial activity of microemulsion-based gel was found to be comparable with marketed cream. RAW 264.7 macrophages were used to determine cell viability (MTT assay) and nitric oxide production. MBG and FA-MBG significantly inhibit the production of the inflammatory mediator NO in LPS-stimulated RAW 264.7 cells in a concentration-dependent manner. The wound healing property was evaluated by histopathological examination and by measuring the wound contraction. The % of wound area in rats treated with FA (2%) loaded microemulsion based gel ranged from 69.30% to 41.39% in the period from 3 to 10 days. In conclusion, FA loaded microemulsion based gel could be offered as encouraging strategy as dermal systems for the burn wound treatment.