A simple spectrophotometric method for determination of cefaclor in raw and dosage forms based on reaction with ninhydrin is developed, optimized and validated. The purple color (Ruhemenn's purple) resulted from the reaction was stabilized and measured at 560 nm.The method optimization was essential as many procedural parameters influenced the accuracy of determination all variables including the reagent concentration, heating time, reaction temperature, color stability period, and cefaclor/ninhydrin ratio were studied in order to optimize the reaction conditions. No interference was observed from common pharmaceutical adjuvant. The developed method is easy to use, accurate and highly cost-effective for routine studies relative to HPLC and other techniques.

The present study was undertaken to develop oral sustained release tablets of metoprolol tartrate using natural hydrophilic matrix formers (xanthan gum and tragacanth). Sustained release matrix tablets of metoprolol tartrate were prepared by using different ratios of drug, xanthan gum and tragacanth. Microcrystalline cellulose (MCC) was used as diluent. The polymer was incorporated into a matrix system using direct compression technique. Different formulations were evaluated with respect to dissolution profile in 900 mL phosphate buffer (pH 6.8), 0.1 M HCl solution and distilled water for 12 h at 37 C. Increasing the amount of polymer (xanthan gum) in the formulation led to slow release of drug. The kinetic treatment showed the best fitted different mathematical models (Zero order, First order, Higuchiis and Hixson-Crowell). Most of the solid matrix formulations followed Higuchi or zero order kinetics. The formulations F1, F2, F3 and F7, F8, F9 showed maximum linearity. The results showed that the formulation F9 containing 30% xanthan gum and 10% gum tragacanth is the most similar to that of the reference marketed preparation.