Formulation and optimization of microemulsion based sparfloxacin in-situ gel for ocular delivery: In vitro and ex vivo characterization

Conventional eye drops have a major limitation of having short residence time in Cul de sac, which is responsible for low bioavailability of the drug and poor therapeutic response. In-situ gel system having a sol-gel transformation is an attractive approach to increase the drug residence time without compromising the advantage of eye drop of easy application. The present investigation was aimed to prepare microemulsified based in-situ gel system of sparfloxacin to improve its solubility and permeability through the cornea. Labrafil M1944 CS, Acrysol–140 and Transcutol-P were used as lipid, surfactant, and co-surfactant respectively to prepare sparfloxacin containing microemulsion. The design batches prepared according to simplex lattice designs were evaluated for globule size, polydispesity index, pH and drug content. Poloxamer 407, a thermo responsive polymer was used as polymer for preparing in situ gel of optimized formulation which was evaluated for clarity, pH, gelling capacity, and the rheological properties. In addition to that ex-vivo drug permeation and ocular irritation studies were also performed. The prepared optimized formulation was found to be clear, stable and non-irritant after 90 days of storage under accelerated stability condition. [Display omitted]