Formulation and evaluation of thermosensitive flurbiprofen in situ nano gel for the ocular delivery

Abstract

The contemporary research implicates the formulation and evaluation of a thermosensitive in situ nano gelling method to improve solubility and ocular residence time of flurbiprofen. This study was carried out in two phases. In the first phase, an insolubility drug has been formulated in the form of a nanoparticulate system and evaluated for its characteristics. The nanoparticles obtained demonstrated an average size array of 150 to 250 nm in diameter, up to 79.35% encapsulation efficiency, and up to 93.42% drug release throughout 2 h. In the second phase, nanoparticulate systems were dispersed in aqueous solutions of Pluronic F 127 (14%) and various concentrations of Carbopol 934 in combination to form an in situ nano gel. The prepared in situ gel was investigated for its physicochemical properties like pH, flowability, sol-gel transition temperature, gelling capacity, and rheological properties. Carbopol 934 did not significantly affect sol-gel transition temperature in optimized concentration (<0.3%) but altered gelling capacity, pH, and transparency of the formulations. In vivo resident time and eye irritation test was evaluated in the rabbit eye. In optimized in situ gelling formulation (NIGF3), approximately 95% of in vitro drug release was observed after 6 h. NIGF3 increased precorneal residence time and high concentration in aqueous humor when paralleled to flurbiprofen eye drops. Greater concentration of drug in aqueous humor was due to its improved saturation solubility of the drug, and amplified residence time was attributed to the formation of gel matrix-embedded nanoparticles. This demonstrated that in situ nano gels (NIGF3) comprehending aqueous solutions of 0.3% w/v concentrations of Carbopol 934 with Pluronic F 127 may ominously persist the residence time and mend bioavailability of a water-insoluble drug.