Development and Evaluation of in situ eye gel for delivery of gatifloxacin and betamethasone sodium phosphate

Abstract

Drug delivery to ocular tissues is challenging due to the rapid removal of instilled drugs due to the low resident time in ocular tissues. The study aimed to formulate an ophthalmic in situ gel that delivers two drugs (betamethasone sodium phosphate [BSP] and gatifloxacin [GTN]). The new combination will allow the simultaneous administration and extended release of the two drugs, which could potentially improve resident time in ocular tissues, patient compliance, and treatment adherence. Formulations containing different gelling agents at different concentrations were prepared to choose the optimum combination regarding physical properties and release. Formulations containing 17% poloxamer 407 and 0.5% gellan gum with different percentages of methylcellulose were prepared and compared regarding gelation temperature, gelling capacity, gelation time, and release and mucoadhesive, permeation study. Increasing the concentration of MC enhanced all the physical properties of the poloxamer-gellan gum gel. The optimum formula (F3) which contains 0.3% MC had a gelation time of 5 sec. at 31oC and remained in gel form for 24 hr. Both drugs had extended-release time and increased the viscosity and mucoadhesion force of the preparation. The results indicated an outsized increase in viscosity at 37°C with the addition of MC which provided sustained release of the drug over 10 hours. and the formulation is isotonic to the eye as well no irritation on the rabbit eye was observed when tested on animals. Conclusion: F3 in situ gel was used to produce a simultaneous and prolonged release of the two drugs. The capacity to administer hydrophilic and hydrophobic medications using a single formulation, eliminating the need for two drops, will increase patient compliance and, consequently, treatment compliance.

Keywords

• in situ gel
• poloxamer
• gellan gum
• methylcellulose
• betamethasone
• gatifloxacin