ABSTRACT
A spectrophotometric procedure was developed for the determination of orphenadrine citrate [I], tizanidine hydrochloride [II] and pancuronium bromide [III]. The method was based on ion-pair complex formation with molybdenum [V] thiocyanate complex in an acidic medium. Dichloromethane was used for the extraction of the orange red ion-pair and its absorbance was measured at 470 nm. The molar absorptivities were 1.34 x 104, 1.19 x 104 and 4.35 x 104 1 mol-1 cm-1 for I, II and III, respectively. The ion-pair was stable for more than one day at room temperature. The proposed method was applied successfully for the analysis of samples in bulk powder and in dosage forms with recoveries in the range of 99-101%, 99.8-101.4% and 98.9-101.2%, respectively
Subject(s)
Spectrophotometry , /chemistry , Thiocyanates/chemistry , Orphenadrine/analysis , Pancuronium/analysis , IonsABSTRACT
A simple, accurate and highly-sensitive spectrophotometric method for the rapid determination of ampicillin trihydrate and cloxacillin sodium in the pure state, their mixtures and pharmaceutical preparations was described. The method is based on the formation of deep color complexes by the reaction of ampicillin trihydrate [amp.] or cloxacillin sodium [clox.] with bromothymol blue [BTB] at 25 and 50C +/- 2C, respectively, in basic solution containing 30% [v/v] acetone. The effect of pH, time, temperatures, solvent and amount of BTB have also been studied. Beer's law is obeyed within the concentration range 0.4-18 and 0.4-20 mug/ml of amp. and clox., respectively, whereas the optimum concentration ranges as evaluated by Ringbom's method are 1-16 and 1-17 mug/ml, respectively. The specific absorptivity, molar absorptivity, Sandell sensitivity, standard deviation and recovery% are evaluated. The method has been used to determine each of amp. and clox. in pure form, synthetic binary mixtures and pharmaceutical preparations [capsules, vials, syrup and drops] containing both of them