Mahaveer B. Melwanki

Sensitive spectrophotometric methods for the determination of amoxycillin, ciprofloxacin and piroxicam in pure and pharmaceutical formulations

Two simple, sensitive and accurate spectrophotometric methods have been proposed for the determination of amoxycillin (AMX), ciprofloxacin (CPF) and piroxicam (PIR) in pure and pharmaceutical preparations. The methods are based on the measurement of absorbances of tris(o-phenanthroline) iron(II) [method A] and tris (bipyridyl) iron(II) [method B] complexes at 510 and at 522 nm, respectively. Reaction conditions have been optimized to obtain coloured complexes of higher sensitivity and longer stability. The absorbances were found to increase linearly with increase in concentrations of AMX, CPF and PIR which were corroborated by correlation coefficient values. The complexes obeyed Beers law over the concentration range of 0.06-5.2, 0.04-7.2 and 0.2-6.5 microg ml(-1) for AMX, CPF and PIR, respectively, in method A, and of 0.05-8.5, 0.05-9.0 and 0.05-6.5 microg ml(-1) for AMX, CPF and PIR, respectively, in method B. The developed methods have been successfully applied for the determination of AMX, CPF and PIR in bulk drugs and pharmaceutical formulations. The common excipients and additives did not interfere in their determinations. The results obtained by the proposed methods have been statistically compared by means of Student t-test and by the variance ratio F-test.

Extractive spectrophotometric determination of ceterizine HCl in pharmaceutical preparations.

Two simple, rapid and sensitive extractive spectrophotometric methods have been developed for the assay of ceterizine hydrochloride (CTZH) in bulk drug and in pharmaceutical preparations. These methods are based on the formation of chloroform soluble complexes between CTZH with bromocresol purple (BCP) or bromophenol blue (BPB) in Walpole buffer of pH 2.64 with an absorption maximum at 409 nm and at 414 nm for BCP and BPB, respectively. Reaction conditions were optimised to obtain the maximum colour intensity. The absorbance was found to increase linearly with increase in concentration of CTZH, which was corroborated by the calculated correlation coefficient value (0.9991-0.9995). The system obeyed Beers law in the range of 1-16 and 1.5-21 microl x ml(-1) for BCP and BPB, respectively. The various analytical parameters have been evaluated. The results obtained by the proposed methods were statistically compared by means of students t-test and by the variance ratio, F-test with those of the reported method and have shown to be in excellent agreement with the reported method.

High-Performance Liquid Chromatographic Method for the Determination of Nimesulide in Pharmaceutical Preparations

A simple, rapid, and precise high-performance liquid chromatographic method for the determination of nimesulide in pharmaceutical preparations was proposed using Ibuprofen as an internal standard. The separation was performed on a CLC C18 (5 μm, 25 cm × 4.6 mm i.d.) column with a mobile phase consisting of an acetonitrile–0.05 M KH2PO4 buffer mixture of pH 7.00 (55 : 45, v/v). The detection was carried out at 230 nm and the linearity range was found to be 0.5–100 μg/mL. The method has been applied successfully to the determination of nimesulide in pharmaceutical formulations. The recovery values were found to be in the range of 99.23–100.13% with RSD values of less than 0.97%.

Spectrophotometric Determination of Antiallergic Drug in Bulk Powder and in Its Pharmaceutical Formulations

Two simple, rapid and selective spectrophotometric methods have been described for the determination of promethazine hydrochloride (PMH) either in pure or pharmaceutical formulations. The methods are based on the formation of a green colored product with sulphanilic acid (SPA) in presence of N-bromosuccinimide (NBS) or a red colored, chloroform soluble product with p-nitroaniline (PNA) in presence of ceric ammonium sulphate (CAS). The chromogen formed has maximum absorption at 600 nm and at 510 nm with SPA and PNA, respectively. The optimum reaction conditions and other analytical parameters are evaluated. Beers law is valid in the concentration range of 0.5–25 μg/mL (R= 0.9983) with SPA and 2–75 μg/mL (R = 0.9981) with PNA. Molar absorptivity values as calculated from the Beers law data are 5.54 × 103 L/mol/cm and 3.05 × 103 L/mol/cm for SPA and PNA, respectively. The results are in good agreement with those of the official method. No interference was observed from common pharmaceutical excipients.