Spectrophotometric-Assisted Chemometric Method for the Simultaneous Analysis of Furosemide, Carbamazepine, Diazepam, and Carvedilol in Their Bulk and Marketed Formulation

Simultaneous determination of Furosemide, Carbamazepine, Diazepam, and Carvedilol in bulk and pharmaceutical formulation using the partial least squares regression (PLS-1 and PLS-2) is described in this study. The two methods were successfully applied to estimate the four drugs in their quaternary mixture using UV spectral data of 84synthetic mixtures in the range of 200-350nm with the intervals ∆λ=0.5nm. The linear concentration range were 1-20 µg.mL-1 for all, with correlation coefficient (R2) and root mean squares error for the calibration (RMSE) for FURO, CARB, DIAZ, and CARV were 0.9996, 0.9998, 0.9997, 0.9997, and 0.1128, 0.1292, 0.1868,0.1562 respectively for PLS-1, and for PLS-2 were 0.9995, 0.9999, 0.9997, 0.9998, and 0.1127, 0.1205, 0.1691, and 0.1686 respectively. Satisfactory results were achieved with applying PLS-1 and PLS-2 in the determination of the cited drugs in their pharmaceutical formulations and a good agreement was found between the proposed methods. Keywords: PLS, spectrophotometry, furosemide, carbamazepine, diazepam, and carvedilo

Simple RP-HPLC Method for Estimation of Furosemide, Carbamazepine, Diazepam and Carvedilol in Bulk and Pharmaceutical Dosage Forms

A simple reverse-phase high performance liquid chromatographic method for the simultaneous analysis (separation and quantification) of furosemide (FURO), carbamazepine (CARB), diazepam (DIAZ) and carvedilol (CARV) has been developed and validated. The method was carried out on a NUCLEODUR® 100-5 C18ec column (250 x 4.6 mm, i. d.5µm), with a mobile phase comprising of acetonitrile: deionized water (50: 50 v/v, pH adjusted to 3.6 ±0.05 with acetic acid) at a flow rate 1.5 mL.min-1 and the quantification was achieved at 226 nm. The retention times of FURO, CARB, DIAZ and CARV were found to be 1.90 min, 2.79 min, 5.39 min and 9.56 min respectively. The method was validated in terms of linearity, accuracy, precision, limit of detection and limit of quantitation. The developed method was successfully applied for the estimation of furosemide, carbamazepine, diazepam and carvedilol in bulk and in pharmaceutical dosage forms. Keywords: RP-HPLC, Furosemide, Carbamazepine, Diazepam and Carvedilo

Spectrophotometric Determination of Sulfanilamide in Pure and in Synthetic Sample based on Condensation Reaction Method

A new, Simple, sensitive and accurate spectrophotometric methods have been developed for the determination of sulfanilamide (SNA) drug in pure and in synthetic sample. This method based on the reaction of sulfanilamide (SNA) with 1,2-napthoquinone-4-sulphonic acid (NQS) to form N-alkylamono naphthoquinone by replacement of the sulphonate  group of the naphthoquinone sulphonic acid by an amino group. The colored chromogen shows absorption maximum at 455 nm. The optimum conditions of condensation reaction forms were investigated by: (1) univariable method, by optimizing the effect of experimental variables; (different bases, reagent concentration, borax concentration and reaction time),     (2) central  composite design (CCD) including the effect of three experimental factors (reagent concentration, borax concentration, and reaction time). The linearity ranges of sulfanilamide are (5-30 µg.mL-1) at 455 nm with molar absorptivity (6.9568×104 - 7.0774×104 L.mol-1.cm-1), Sandell's sensitivity index (2.4753 - 2.4330 μg.cm-2) and detection limit of (0.546 – 0.536 µg.mL-1) for each procedure respectively. The results showed there are no interferences of excipients on the determination of the drug. The proposed method has been successfully applied for the determination of sulfanilamide in pure and in synthetic sample. Keywords: Spectrophotometric determination, Sulfanilamide, Central  composite design, 1, 2-napthoquinone-4-sulphonic acid (NQS)

A Highly Sensitive Kinetic-Spectrophotometric Method for the Assay of Carbamazepine in Pure and Commercial Tablet

The study aimed to recommend a new spectrophotometric-kinetic method for determination of carbamazepine (CABZ) in its pure form and pharmaceutical forms. The proposed procedure based on the coupling of CABZ with diazotized sulfanilic acid in basic medium to yield a colored azo dye. Factors affecting the reaction yield were studied and the conditions were optimized. The colored product was followed spectrophotometrically via monitoring its absorbance at 396 nm. Under the optimized conditions, two method (the initial rate and fixed time (10 minute)) were applied for constructing the calibration graphs. The graphs were linear in concentration ranges 2.0 to 18.0 µg.mL-1 for both methods. The proposed was applied successfully in the determination of CABZ in its commercial formulations. Keywords: Kinetic, Spectrophotometry, Carbamazepine, Pharmaceutical formulation