Liquid chromatographic determination of ceterizine hydrochloride and paracetamol in human plasma and pharmaceutical formulations.

An accurate, simple, reproducible and sensitive HPLC method for the determination of ceterizine hydrochloride (CTZH) and paracetamol (PARA) has been developed and validated. The separation of CTZH, PARA and Nimesulide (the internal standard) was achieved on a CLC C(18) (5 mu, 25 cm x 4.6 mm i.d) column using UV detection at 230 nm. The mobile phase was consisted of acetonitrile-water (55:45 v/v). The linear ranges of detection for CTZH and PARA were found to be 0.715-55 microg/ml (r(2)=0.9985) and 0.55-39 microg/ml (r(2)=0.9957) respectively. Intra- and inter-day assay relative standard deviations were less than 1%. The method has been applied successfully to the determination of binary combination of CTZH and PARA in human plasma and pharmaceutical preparations. There was no interference from drugs commonly administered with CTZH and PARA. The method has been shown to be linear, reproducible, specific, and rugged.

Extractive spectrophotometric determination of fluoroquinolones and antiallergic drugs in pure and pharmaceutical formulations.

A simple, rapid and sensitive spectrophotometric procedure has been proposed for the assay of fluoroquinolones viz., ciprofloxacin (CPF) and norfloxacin (NRF), and antiallergic drugs viz., methdilazine hydrochloride (MDH) and isothipendyl hydrochloride (IPH) in bulk and pharmaceutical formulations. The method is based on the reaction of selected drugs with Brilliant Blue G (BBG) in NaOAc-AcOH buffer of pH 4.0 for CPF and NRF or in neutral medium for MDH and IPH to give chloroform soluble ion-association complexes. The effects of various parameters have been studied. The ion-association complexes exhibited absorption maxima at 610 nm for CPF, at 614 nm for NRF and MDH, and at 612 nm for IPH. Beer's law plots were obeyed in the concentration ranges of 0.5-6.0, 0.4-8.0, 0.1-6.0 and 0.2-6.1 (mg ml(-1) for CPF, NRF, MDH and IPH, respectively, with correlation coefficients not less than 0.9969. Molar absorptivity values as calculated from the Beer's law data were found to be 2.86 x 10(4), 2.64 x 10(4), 3.13 x 10(4) and 5.51 x 10(4) mol(-1) cm(-1) for CPF, NRF, MDH and IPH, respectively. The influence of commonly employed excipients in the determination of the studied drugs has been studied. The results obtained by the proposed method were statistically validated.

Indirect spectrophotometric determination of propranolol hydrochloride and piroxicam in pure and pharmaceutical formulations.

Two simple and sensitive indirect spectrophotometric methods for the assay of propranolol hydrochloride (PPH) and piroxicam (PX) in pure and pharmaceutical formulations have been proposed. The methods are based on the oxidation of PPH by a known excess of standard N-bromosuccinimide (NBS) and PX by ceric ammonium sulfate (CAS) in an acidic medium followed by the reaction of excess oxidant with promethazine hydrochloride (PMH) and methdilazine hydrochloride (MDH) to yield red-colored products. The absorbance values decreased linearly with increasing concentration of the drugs. The systems obeyed Beer's law over the concentration ranges of 0.5 - 12.5 and 0.3 - 16.0 microg/ml for PPH, and 0.4 - 7.5 and 0.2 - 10 microg/ml for PX with PMH and MDH, respectively. Molar absorptivity values, as calculated from Beer's law data, were found to be 1.36 x 10(4) and 2.55 x 10(4) l mol(-1) cm(-1) for PPH, and 2.08 x 10(4) and 2.05 x 10(4) l mol(-1) cm(-1) for PX with PMH and MDH, respectively. The common excipients and additives did not interfere with their determinations. The proposed methods have been successfully applied to the determinations of PPH and PX in various dosage forms. The results obtained by the proposed methods compare favorably with those of official methods.