 2: 11611170 (2011) ewsletter Jangde   1161 FORMULATIO DEVELOPMET AD EVALUATIO OF SUSPESIO OF GATIFLOXACI USIG SUSPEDIG AGET Rajendra Jangde 1 *, Sanjay J. Daharwal 1 , Ram Kumar Sahu 2 , Jagdish Singh 3 1. University Institute of pharmacy, Pt. Ravishankar Shukla University, Raipur (C.G.)492010, India, 2. Department of Pharmacognosy, Oriental College of Pharmacy, Bhopal (M.P.) 462021, India. 3. Department of Technical Education, Govt. of Punjab, Chandigarh, India. For e. mail correspondence: rjangdepy@gmail.com Summary In the present investigation, an attempt has been made for formulation and evaluation of gatifloxacin suspension by adding acacia powder in different ratio in all five formulations. The five suspensions (F1 to F5) of gatifloxacin were prepared by using different ratio of acacia powder (0.5, 1.0, 1.5, 2.0, and 2.5% w/v). These formulations were evaluated for sedimentation volume, pH measurement, viscosity measurement, particle size, and drug release at various time intervals for 3 months. As part of preformulation studies, FTIR and Differential scanning calorimetry was used to investigate the physicochemical compatibility between gatifloxacin and various excipients used in suspension manufacturing. The gatifloxacin was found to be compatible with different excipients. The results of the study indicated on increasing the concentration of acacia powder in suspensions improved the physical stability. Formulation F3 and F5 shows satisfactorily physical stability while F4 containing 2.0% w/v concentration of acacia showed better physical stability, and was found to be optimum concentration. Among the formulated suspensions F4 showed better   drug release profile as well as better physical stability compared to other formulated suspensions. Keywords: Gatifloxacin, suspension, excipients, compatibility Introduction A pharmaceutical suspension, like other disperse systems, is thermodynamically unstable, thus making it necessary to include a stabilizer or suspending agent in the formulation which reduces the rate of settling and permits easy redispersion of any settled particulates both by protective colloidal action and by increasing the consistency of the suspending medium [1,2]. Gatifloxacin is a synthetic broad spectrum 8methoxyfluoroquinolone antibacterial agent for oral or intravenous administration. It is bactericidal and its mode of action depends on blocking of bacterial DNA replication by binding itself to an enzyme called DNA gyrase, which allows the untwisting required replicating one DNA double helix into two. Notably the drug has 100 times higher affinity for bacterial DNA gyrase than for mammalian. Gatifloxacin is a broadspectrum antibiotic that is active against both Grampositive and Gramnegative bacteria.