SIMULTANEOUS HPLC-DETERMINATION OF NORTRIPTYLINE AND FLUPHENAZINE IN ONE MINUTE USING MONOLITHIC STATIONARY PHASE

Simultaneous spectrophotometric determination of fluphenazine HCl and nortriptyline HCl in presence of their potential impurities perphenazine and dibenzosuberone in bulk and pharmaceutical formulation

Fluphenazine HCl (FLU) is an anxiolytic, while Nortriptyline HCl (NOR) is an anti-depressant. They are co-formulated together to treat depression and schizophrenia. Perphenazine (PER) and dibenzosuberone (DBZ) are the pharmacopeial impurities of FLU and NOR, respectively. Four spectrophotometric and multivariate chemometric methods were developed to determine the two drugs together or in presence of their two impurities in their bulk and pharmaceutical formulation. Method (A) is the triple divisor-ratio derivative (TDR) method, where the zero order spectrum of each component was divided by a mixture of the other 3 components, then the peak amplitudes of the first derivative spectra of FLU, NOR and DBZ were measured at 265, 245.4 and 283.2 nm, respectively. Method (B) is the double divisor-ratio difference-dual wavelength (DD-RD-DW) method, in which each component spectrum mixture was divided by a binary mixture of 2 of the interfering components. In the resulting ratio spectra, the amplitude difference is calculated between 2 wavelengths at which the third interfering component has zero difference. Methods (C and D) are the principle component analysis (PCA) and partial least squares (PLS) models. Methods (A and B) failed to quantify PER (FLU impurity), while (C and D) succeeded to quantify all components. The four methods have been applied for the prediction of the FLU and NOR in their pharmaceutical formulation with good accuracy and precision. The proposed methods have been validated according to the ICH guidelines and the results were within the acceptable limits.

Difference spectrophotometric method for the determination of Fluphenazine hydrochloride in tablets using peroxomonosulfate

The oxidative derivatization method using potassium hydrogenperoxomonosulfate for the indirect spectrophotometric determination of Fluphenazine hydrochloride is presented. Potassium hydrogenperoxomonosulfate is introduced as a derivatizing agent for Fluphenazine hydrochloride, yielding the sulfoxide. This reaction product was successfully used for the spectrophotometric determination of the Fluphenazine hydrochloride. The UV spectroscopic detection of the sulfoxide proved to be a more robust and sensitive method. The elaborated method allowed the determination of Fluphenazine hydrochloride in the concentration range of 0.2-30 µg mL-1. The molar absorptivity at 349 nm is 5.6×103 (dm3cm-1mol-1). The limit of quantification, LOQ (10S) is 0.24 µg/mL. A new spectrophotometric technique was developed and the possibility of quantitative determination of Fluphenazine hydrochloride in tablets 5.0 mg was demonstrated. The present method is precise, accurate and excipients did not interfere. RSD for Fluphenazine Hydrochloride 5.0 mg tablets was 1.37 %.

Development and validation of a rapid stability indicating HPLC-method using monolithic stationary phase and two spectrophotometric methods for determination of antihistaminic acrivastine in capsules

Simple, rapid and accurate high performance liquid chromatographic (HPLC) and spectrophotometric methods are described for determination of antihistaminic acrivastine in capsules. The first method (method A) is based on accurate, sensitive and stability indicating chromatographic separation method. Chromolith® Performance RP-18e column, a relatively new packing material consisting of monolithic rods of highly porous silica, was used as stationary phase applying isocratic binary mobile phase of ACN and 25 mM NaH2PO4 pH 4.0 in the ratio of 22.5:77.5 at flow rate of 5.0 mL/min and 40°C. A diode array detector was used at 254 nm for detection. The elution time of acrivastine was found to be 2.080±0.032. The second and third methods (methods B and C) are based on the oxidation of acrivastine with excess N-bromosuccinimide (NBS) and determination of the unconsumed NBS with, metol-sulphanilic acid (λmax: 520 nm) or amaranth dye (λmax: 530 nm). The reacted oxidant corresponds to the drug content. Beer's law is obeyed over the concentration range 1.563-50, 2.0-20 and 1.0-10 μg mL(-1) for methods A, B and C, respectively. The limits of detection and quantitation were 0.40, 0.292 and 0.113 μg mL(-1) and 0.782, 0.973 and 0.376 μg mL(-1) for methods A, B and C, respectively. The HPLC method was validated for system suitability, linearity, precision, limits of detection and quantitation, specificity, stability and robustness. Stability tests were done through exposure of the analyte solution for four different stress conditions and the results indicate no interference of degradants with HPLC-method. The proposed methods was favorably applied for determination of acrivastine in capsules formulation. Statistical comparison of the obtained results from the analysis of the studied drug to those of the reported method using t- and F-tests showed no significant difference between them.