DESIGN, DEVELOPMENT AND IN VITRO EVALUATION OF MODIFIED RELEASE HYDROGEL BASED DRUG DELIVERY SYSTEMS OF OSELTAMIVIR PHOSPHATE

Hydrogels are 3-dimensional hydrophilic polymeric networks composed of homo or co-polymers capable of imbibing large amounts of biological fluids. They can be tailored as modified release dosage forms for both hydrophilic and hydrophobic drugs. The present study was aimed to develop and characterize oral hydrogel based drug delivery systems of Oseltamivir phosphate by physical cross-linking polymerization technique using guar gum and starch as hydrophilic carriers and hydroxy ethyl methacrylate. The hydrogel tablets were dried and the drug was loaded by imbibition from the drug solution. The compatibility of drug with the polymers was confirmed by Infrared spectroscopy. Differential scanning calorimetric studies confirmed the nature of the drug in the hydrogel formulations. Surface morphology studied by scanning electron microscopy revealed the rough and contour outer surface. The hydrogel tablets were further studied for entrapment efficiency, swelling kinetics at various pH and in vitro drug release. The results showed a good entrapment efficiency of about 85.6% and the swelling rate was found to be 98.33 at higher pH. The percentage drug release was also higher as the pH increased and was found to be highest in F4 formulation (87.39%) in 24 hrs. Further, the release kinetics was observed to follow first order, super case II transport mechanism. The stability studies showed that the hydrogel formulations prepared using starch, guar gum and hydroxy ethyl methacrylate offer good stability to the drug. It was hence concluded that the hydrogel drug delivery systems could be appropriate as a modified release drug delivery system.