Simultaneous determination of losartan and hydrochlorothiazide in pharmaceutical preparations by derivative and ratio derivative spectrophotometry

Losartan is a non-peptide potent antihypertensive agent that acts through blocking angiotensin n receptors. Hyzaar is a combination product that contains two drugs, losartan and hydrochlorothiazide, used to lower high blood pressure. There are some reports regarding simultaneous measurement of the drugs in pharmaceutical and biological samples which includes HPLC, CE, CEC, and multisyringe chromatography. UV-V is spectra of standard solutions of losaratan and hydrochlorothiazide were prepared separately and together in combination with various concentrations of the drugs. To determine these two drugs simultaneously without any preliminary treatment, losartan was determined by ratio derivative Spectrophotometry at third derivation with ? lamda = 10 nm at 246.3 nm, and hydrochlorothiazide was determined at first derivation with delta lamda = 5nm at 334.4 nm. This method was used to determine the two drugs in real samples of tablets. The method had a good linearity in the concentration range studied [r > 0.999]. Precision of the method revealed that RSD% was lower than 2.10 and 1.79 for losartan and hydrochlorothiazide, respectively. Accuracy of the method on the basis of error% was lower than 3.3% for losartan and 2.3% for hydrochlorothiazide. Based on the validation results, it could be concluded that the method was reliable and valid for determination of the drugs in their preparations. Real sample analysis showed that tablets had 84.9% hydrochlorothiazide and 92.6% losartan compared to label amount of the drugs. Results depicted a simple, valid, inexpensive and reliable method for simultaneous determination of the two drugs in pharmaceutical preparations applicable to the quality control laboratory of pharmaceutical industries

[Determination of aflatoxin M1 in pasteurized milk consumed in Kerman province]

Aflatoxrn M1 [AFM1] is a major metabolite of aflatoxin B1 detected in the milk of mammals that their foods have been contaminated with aflatoxins. Aflatoxins are a group of highly toxic metabolites produced by the common fungi Aspergillus flavus, A. parasiticus. They are among the most potent carcinogens found in foods. Considering its risk to the human health and high consumption of milk and diary products, this study was undertaken to determine the level of AFM1 in pasteurized milk in Kerman province for the first time. From 19 Dec. 2007 to 19 March 2008, a total of 76 pasteurized milk samples produced by eight factories were collected and checked for the level of AFM1 using immunoaffinity column and high-performance liquid chromatography coupled to fluorimetric detector. The minimum detected level was 0.002 ppb and the amount of AFM1 in milk samples ranged from 0.002 to 0.14 ppb. No sample had greater AFM1 levels than the maximum allowed levels in milk accepted by FDA [o.5ppb], however, in 34 [44.7%] samples AFM1 level was over the maximum allowed limit in milk accepted by the European Union [0.05ppb]. Mean AFM1 level in milk samples obtained from Jiroft factory was the least [0.019 +/- 0.01ppb] compared to that for other factories. Although the amount of AFM1 in samples selected from commonly consumed milks in Kerman province, does not appear to create a serious public health problem at present, because of high consumption of milk and diary products especially in children it is necessary to consider it as a serious health problem