FORMULATION AND IN-VITRO EVALUATION OF FLOATING TABLETS OF HYDROXYPROPYL METHYLCELLULOSE K4M AND CARBOPOL-934P USING METRONIDAZOLE AS A MODEL DRUG

In the present study, metronidazole was used for preparing floating dosage forms that are designed to retain in the stomach for a long time and have developed as a drug delivery system for better eradication of Helicobacter Pylori in peptic ulcer diseases. Hydroxypropyl methylcellulose (HPMC K₄M) and Carbopol-934P of different ratio were used to prepare Hydrodynamically Balanced Systems (HBS) by direct compression technique. The prepared HBS tablets were evaluated in terms of their pre-compression parameters and post-compression parameters like hardness, friability, weight variation, uniformity of drug content, percentage swelling, in-vitro floating studies, in-vitro drug release and short term stability studies. The floating properties and drug release characteristics were determined for the prepared HBS in 0.1 N HCl dissolution media. All the HBS formulations showed good in-vitro floating properties with an optimum concentration of gas generating agents; sodium bicarbonate and citric acid. The rate of drug release decreased with increased hardness of tablets. Optimum concentration of HPMC K₄M (140 mg) and Carbopol-934P (10 mg) along with excipients was found to be beneficial in improving the drug release rate and floating properties. Among the eight formulations, F8 was selected as the best formulation as its lag time was 10.3 seconds, percentage swelling 119.91% at 4^th hour and % drug release 75.62% at 8^th hour with buoyancy time  >12 hours.