Simple and rapid HPLC method for simultaneous determination of atenolol and chlorthalidone in spiked human plasma

A simple, sensitive and rapid chromatographic method was developed and validated for the simultaneous quantification of atenolol and chlorthalidone in human plasma using hydrochlorothiazide as internal standard [IS]. The method utilized proteins precipitation with acetonitril as the only sample preparation involved prior to reverse phase-HPLC. The analytes were chromatographed on Shim-pack cyanopropyl column with isocratic elution with 10 mM KH2PO4 [pH 6.0] - methanol [70:30, v/v] at ambient temperature with flow rate of 1 mL min-1 and UV detection at 225 nm. The chromatographic run time was less than 10 min for the mixture. The calibration curves were linear over the range of 0.1-10 mg mL-1. The method was validated in terms of accuracy, precision, absolute recovery, freeze-thaw stability, bench-top stability and re-injection reproducibility. The within- and between-day accuracy and precision were found to be within acceptable limits <15%. The analytes were stable after three freeze-thaw cycles [deviation <15%]. The proposed method was specific for the simultaneous determination of atenolol and chlorthalidone in human plasma where there was no interference from endogenous biological substances

HPLC method for simultaneous determination of amiloride hydrochloride and hydrochlorothiazide in human plasma

A simple, sensitive and rapid chromatographic method was developed and validated for the quantification of a binary mixture namely; [amiloride hydrochloride and hydrochlorothiazide] in human plasma using chlorthalidone as internal standard [IS]. The method utilized proteins precipitation with acetonitril as the only sample preparation involved prior to reverse phase-HPLC. The analytes were chromatographed on Shim-pack cyanopropyI column with isocratic elution with 10 mM KH[2]PO[4] [pH 4.50]-methanol [70:30 v/v] at ambient temperature with flow rate 1 ml/min and UV detection. The chromatographic run time was less than 10 min for the mixture. The calibration curves were linear over the range 0.1-10 micro g ml[-1]. The method was validated in terms of accuracy, precision, absolute recovery, freeze-thaw stability, bench-top stability and re-injection reproducibility. The within-and between-day accuracy and precision were found to be within acceptable limits <15%. The analytes were stable after three freeze-thaw cycles [deviation <15%]. The proposed method is specific for determination of the mixture in human plasma where there is no interference from endogenous biological substances

Stability-indicating spectrophotometric method for determination of Moexipril-HCL in bulk and pharmaceutical formulation

Three simple, sensitive and accurate spectrophotometric procedures have been established for the assay of Moexipril-HCI in bulk form, in pharmaceutical formulations, and in the presence of its degradation products. The procedures are based on the reaction between the examined drug and bromocresol purple [BCP], bromophenol blue [BPB], and bromothymol blue [BTB] in aqueous acidic medium producing an ion-pair complexes extracted in chloroform and measured at the optimum wavelengths. Reaction conditions were studied and optimized to obtain the maximum color intensity. The reactions were extremely rapid at room temperature and the absorbance values remains unchanged for 48 h. Beer's law was obeyed in the concentration ranges 4-32, 4-24, and 4-40 microg ml[-1] with molar absorptivities of 1.7x10[4], 2.1x10[4], and 1.5x10[4] mol[-1] cm[-1] and detection limit of 0.064, 0.065, and 0.077 microg ml[-1] for BCP, BPB, and BTB methods, respectively. The proposed methods have been applied successfully for the analysis of the drug in pure form and in its dosage forms with percentage recoveries range from 99.29 - 100.11. Statistical comparison of the results with those obtained by second derivatives spectrophotometric method shows excellent agreement and indicates no significant difference in accuracy and precision

Synthesis and evaluation of some new 2.4- [1H.3H] -quinazolinedione derivatives as potential analgesic and anti-inflammatory agents

A series of 1-[3-trifluoromethylphenyl]-2, 4-[1H,3H]- quinazolinedione derivatives was synthesized as potential analgesic and anti- inflammatory agents. Structures were confirmed by elemental analysis and spectral data. Five compounds were tested for analgesic and anti- inflammatory activities. Two compounds II and VI exhibited significant analgesic and anti-inflammatory activities compared with flufenamic acid