Selective HPLC-quantification of promethazine hydrochloride and its degradation products in presence of sodium benzoate

A selective and stability-indicating RP-HPLC method has been developed and validated for the simultaneous precise determination of promethazine [PROM] and sodium benzoate [SBENZ], even in the presence of the main oxidative degradation products of PROM. Good separation could be achieved on a C8-column by using a mobile phase composed of 0.008M ammonium acetate [pH 4.7] + methanol = 52 48, v/v by adopting isocratic programmed elution with UV-detection at 253 nm. The method was linear over the concentration ranges of 4- 60 micro g ml[-1] and 0.2-3 mg ml[-1], with accuracy of 100.68 +/- 1.49% and 101.82 +/- 0.91% and limits of quantitation [LOQ] of 0.8 micro g ml[-1] and 20 micro g ml[-1], for PROM and SBENZ, in orders. The method was successfully adopted for the stability-screening and -improvement of PROM in presence of SBENZ in their syrups

Photochemical studies on drugs.3. photostability-indicating HPLC-method for determination of thioridazine

Accelerated photolysis of aqueous solutions of thioridazine hydrochloride is investigated. Spectral alterations due to drug irradiation were monitored as a function of time. A selective high performance liquid chromatographic [HPLC] procedure for the quantification of the psychotic drug, in the presence of its photolytic degradation products, is demonstrated. Complete resolution of the unchanged drug from its photodegradates was achieved isocratically at a flow rate of 0.8 ml.min.[-1] on a [micro]- PorasiI [TM] 125A column [10 [micro]m, 30 cm x 3.9 mm, i.d.] utilizing a mobile phase containing methanol-acetonitrile-water-25%, w/w ammonia [94.75:2.5:2:0.75, by volumes] with UV -detection [254 nm] at ambient temperature

Quantification of amidin and amidin in pharmaceutical preparations by high performance liquid chromatography and derivative spectrophotometry

Two different methods, namely high performance liquid chromatography [HPLC] and derivative spectrophotometry-have been developed for determination of ammidin and/ or ammoidin in pure forms, binary mixtures and dosage formulations [paints].in the first method, the two drug substances couldbe resolved on a reversed-phase RP-C18 LiChrosorb [10 micro m] column by isocratic elution with a solvent mixture containing acetonitrile and water [70.30, by volumes] at a flow rate of 1ml. Min-1 with UV-detection at 254 nm. The complete HPLC- resolution of both coumarins needs only about 6 minutes. The other method adopts the first derivative [D1 [dA/d lambda] spectrophotometric measurement of ammidin and ammoidin in their ethanolic solutions or extracts at about 227 nm and 248 nm, respectively. The results obtained from the two methods have been statistically have been statistically evaluated and compared

Gas-liquid chromatographic determination of nicotinic acid niacin in pharmaceutical preparations

A rapid quantitative gas-liquid chromatographic [GLC] method for the determination of the pellagra-preventive factor nicotinic acid [niacin], in pure form and in tablets or dragees, is developed. The analyzed antipellagra vitamin requires no sample clean up preliminary vitamin separation or derivatization. The method is adopted for a contraction range varied between 0.5-8 mg/ml of the drug in ethanolic solutions. The method gives good percentage mean accuracy for the pure authentic vitamin and tablets or dragees containing it. Recovery experiment with 15% addition of niacin to the labeled claim in the galencial forms gives percentage mean recoveries of 100.21 0.97% nicotinic acid [BP 80] tablets, 98.80 1.12% aminoverine tablets, and 99.32 0.88% cosaldon [R] retard dragees