Formulation and Evaluation of Azithromycin Dihydrate Based In situ Gel as Floating Drug Delivery System

Floating Drug Delivery Systems have been used to overcome some of the problems like low oral absorption of drugs with narrow absorption window as it has an advantage of sustained release of drugs over a prolonged period of time. In-situ gels are the novel approach in the context of floating drug delivery systems. The aim of this present study was to develop an oral stomach specific floating in-situ gel of Azithromycin dihydrate. In-situ gelling system was prepared by dissolving different concentrations of polymers like sodium alginate, xanthan gum in the de-ionized water already prepared with sodium citrate at 60°C to 90°C. After the heating with continuous stirring the formulation was cooled below the temperature of 40°C with the addition of certain amount of drug and calcium carbonate which acts as gas generating agent. All the formulations showed pH in the range of 6.1 to 6.7, drug content was found to be in the range of 97.29% to 99.27%. Floating lag time was less than 1 minute for all the formulations and the duration of floatation was more than 24 hours for the combination of polymers. Appearance and measurement of water uptake by the gel was also good. Stability studies were also done and was found to be at normal phase at different temperatures and at interval of times. Although, F9 showed the maximum properties of an in-situ gel with increased gastric retention time with low slowly release of the drug. Drug release was found to be decreasing as the concentration of polymer increases. However, it was concluded that the in-situ gelling system of Azithromycin dihydrate could be prepared in various concentrations of different polymers and the combination of polymers to increase the patient compliance and reduction in the frequency of dosing of the drug with the increased gastric residence time for the drug in the stomach.