Kavitha K

The present study was designed to develop simple accurate, precise, reproducible and validating of a stability indicating reverse phase high performance liquid chromatographic (RP-HPLC) method for the simultaneous estimation of azithromycin, ornidazole and fluconazole in bulk and its pharmaceutical dosage forms. Chromatographic separation of the three drugs was performed on a Phenomenex C18 column (250X4.6mm 5μm) as stationary phase with a mobile phase comprising of 20mM potassium dihydrogen phosphate : Acetonitrile (pH 4.8) in the ratio 30:70% v/v at a flow rate of 1ml/min and peak monitored at 254nm using PDA detector. The retention time of azithromycin, fluconazole, ornidazole and procaine hydrochloride (internal standard) was Rt1-2.8, Rt2-5.0, Rt3-6.3 and Rt-3.8minutes respectively. The linearity of azithromycin, fluconazole and ornidazole were in the range of 20-100μg/ml, 3-15μg/ml and 15-75μg/ml with an internal standard, procaine hydrochloride 5µg/ml respectively. The accuracy of the method was found to be 98-102% and %RSD was found to be less than 2% indicating high degree of accuracy and precision of the proposed HPLC method. The limit of detection for azithromycin, fluconazole and ornidazole was found to be 0.34, 2.80 and 0.76μg/ml respectively whereas, the limit of quantification was found to be 1.05, 8.6 and 2.31μg/ml respectively. Forced degradation studies were conducted to know the stability of the drug samples under various stress conditions like acid, base, peroxide and photolytic degradation according to ICH guidelines. Results are validated statistically as per ICH guidelines.

Targeted drug delivery systems deliver the drug to the site of action. Colon Targeted drug delivery is considered as one of the most convenient pathway for the delivery of the drugs or therapeutic agents and used in the treatment of the local diseases. Microencapsulation is widely used in the pharmaceutical and other sciences to mask taste/odors, prolong release, impart stability to drug molecules, improve bioavailability, and as multiparticulate dosage forms to produce controlled or targeted drug delivery. Microencapsulation is the process in which small droplets or particles of liquid or solid material are surrounded or coated by a continuous film of polymeric materials. Microencapsulation system offers potential advantages over the conventional drug delivery systems. In this present article various technologies for the preparation of microcapsules for the purpose of colon targeted drug delivery systems are reviewed.

To increase the bioavailability and short ocular residence time of Norfloxacin eye drops, aqueous solutions of drug in chitosan/ Pluronic (poloxamer) were prepared. Mixtures of solutions of Pluronic (5-17.5% w/w) with chitosan (0.1-0.6% w/w) were prepared.  The formulations so prepared were in the liquid state at 4°C while turned into a gel at the temperature of the Cul-de-sac. Naturals polymers i.e., Poloxamer was used as the polymer which exhibited the phase transition behavior and chitosan was used to improve residence time. Norfloxacin release was determined using a membrane less dissolution model in artificial tear solution up to 8 hours and the samples were analyzed spectrophotometrically at 277nm. The rheological behavior of solutions in response to dilution or temperature changes and also the phase change temperature (PCT) were determined. Antimicrobial effect of the solutions was studied in nutrient agar in comparison to all formulations of Norfloxacin using Pseudomonas aueroginosa, Staphylococcus aureus and E.coli by the agar diffusion test using the cup-plate technique. The formulation consisted of 15% Pluronic and 0.5% chitosan, with the highest release efficiency (73.46 ± 0.876%) and an acceptable mean release time, is suggested as a suitable ophthalmic preparation for sustained release of Norfloxacin.