Gel dosage forms are successfully used as drug delivery systems to control drug release and protect the medicaments from a hostile environment. The main objective is to formulate and evaluate in situ oral gels of repaglinide based on the concept of pH triggered and ion activated systems. The system utilizes polymers that exhibit sol-to-gel phase transition due to change in specific physico-chemical parameters. A pH triggered system consisting of Carbopol 934P (0.2-1.2% w/v) was used to prolong the release of repaglinide (0.1% w/v). Formulations were evaluated for gelling capacity, viscosity, gel strength, floating studies, spreadability, and in vitro release. The use of Carbopol as an in situ gel forming system was substantiated by the property to transform into stiff gels when the pH was raised. The drug content, clarity, and pH of the formulation were found to be satisfactory. The viscosity was found to be in the range 5 to 85 centipoise for the sol, whereas for the gels it was up to 16000 centipoise. The formulation showed pseudo plastic flow with thixotropy. The maximum gel strength (using texture analyser). The optimized formulations were able to release the drug up to 6 h. As it is a floating drug delivery system it shows increased retention and increased bioavailability of drugs.
