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Vizianagaram, India

Prasanthi P.,UCEV JNTUK | Vasanth P.M.,UCEV JNTUK | Ramesh T.,UCEV JNTUK | Malothu R.,UCEV JNTUK
Research Journal of Pharmaceutical, Biological and Chemical Sciences | Year: 2013

Oxidative stress is a factor in many human diseases, as either cause or effect. A convenient biomarker of oxidative stress is the extent of oxidation of bases in DNA (although measures of lipid or protein oxidation may be equally informative). 8-Oxo-7,8-dihydroguanine or the corresponding nucleoside is most often measured, either chromatographically (gas chromatography-mass spectrometry, HPLC with electrochemical detection, or HPLC-tandem mass spectrometry) or enzymically, with the use of the enzyme formamidopyrimidine DNA glycosylase to convert 8-oxo-7,8-dihydroguanine to DNA breaks, which are detected with alkaline elution, alkaline unwinding, or the comet assay. Estimates of background levels of 8-oxo-7,8-dihydroguanine in normal human cells vary 1000-fold, depending on the technique used. Gas chromatography-mass spectrometry is particularly prone to oxidation of samples during derivatization, whereas HPLC suffers from this artifact to a lesser degree. In a recent interlaboratory study that measured the same samples of human cells, median values obtained with HPLC with electrochemical detection and with formamidopyrimidine DNA glycosylase differed by ~10-fold. There are still questions regarding the actual level of damage, but it is probably approximately one 8-oxo-7,8-dihydroguanine residue per 106 guanines. Assays for antioxidant protection against oxidative damage generally depend on measurements of decreases in a marker of oxidation. Potential dietary antioxidants can be screened with in vitro antioxidant assays or tested in cell culture systems. The best test, however, is in humans. The total antioxidant capacity of plasma is generally insensitive to dietary supplementation with antioxidants or antioxidant-rich foods. An increase in the resistance of lymphocyte DNA to oxidation in vitro is commonly seen, however, and a decrease in endogenous oxidation of DNA may be detected, especially after prolonged supplementation.


Jagadeeswararao V.,UCEV JNTUK | Vasanth P.M.,UCEV JNTUK | Ramesh T.,UCEV JNTUK | Ramesh M.,UCEV JNTUK
International Journal of ChemTech Research | Year: 2013

A simple Reverse phase liquid chromatographic method has been developed and subsequently validated for simultaneous determination of Losartan potassium and Hydrochlorothiazide in combination. The separation was carried out using a mobile phase of Buffer and Acetonitrile are taken in 65:35%v/v (adjust pH 3.0 with orthophosphric acid). The column used was Reverse phase C18 column (Agilent XDB C18, 150 x 4.6 mm, 5μ) with flow rate of 1.0 ml min using PDA detection at 254 nm. The described method was linear over a concentration range of 25-75 μg/ml and 6.25-18.75 μg/ml for the assay of losartan potassium and hydrochlorothiazide respectively.The retention times of losartan potassium and hydrochlorothiazide were found to be 4.901 and 2.176 min respectively. Results of analysis were validated statistically and by recovery studies. The limit of quantification (LOQ) for losartan potassium and hydrochlorothiazide were found to be 5.393 and 1.138 μg/ml respectively and the limit of detection (LOD) values were found to be 1.779 ug/ml and 0.375 ug/ml respectively for losaratan potassium & hydrochlorthiazide.Results of the study showed that the proposed RP-HPLC method is simple, rapid, precise and accurate, which is useful for the routine determination of losartan potassium and hydrochlorothiazide bulk drug and in its pharmaceutical dosage form.


Rameezuddin M.D.,UCEV JNTUK | Vasanth P.M.,UCEV JNTUK | Ramesh T.,UCEV JNTUK | Ramesh M.,UCEV JNTUK
International Journal of ChemTech Research | Year: 2013

A simple, fast and precise reverse phase high performance liquid chromatographic method has been developed for the simultaneous determination of Montelukast Sodium (MONT) and Fexofenadine hydrochloride (FEXO). The chromatographic separation was achieved on ACE C8 column (250 mm x 4.6 mm, 4μ particle size) as stationary phase with a mobile phase comprising of ortho phosphoric acid (pH 6.2): methanol (40:60) with flow rate of 1.0 mL/min, column temperature of 28±2oC at a wavelength of 290nm. The retention time of Montelukast Sodium and Fexofenadine hydrochloride were 5.0 min, and 3.2 min respectively. The linearity were found to be in the range of 2-6μg/mL and 24-72mg/mL for Montelukast Sodium and Fexofenadine hydrochloride with correlation coefficient greater than 0.999. The proposed methods were validated as per ICH guidelines and successfully applied for the determination of investigated drugs in tablets.


Rashmita G.,UCEV JNTUK | Vasanth P.M.,UCEV JNTUK | Ramesh T.,UCEV JNTUK | Ramesh M.,UCEV JNTUK
Der Pharma Chemica | Year: 2013

The method developed for simultaneous estimation of Amlodipine besylate and Indapamide by using RP-HPLC method is simple, accurate, selective and economic by using c8 column (BDS Hypersil, 100×4.6mm,5μ particle size). Sample was analysed using water which is adjusted with ortho phosphoric acid buffer (OPA) to pH 3: Methanol in the ratio 600:400 as a mobile phase at a flow rate of 1ml\min. Detection was performed with PDA detector at 248nm. The retention time of Indapamide and Amlodipine besylate is 1.45 & 3.30 respectively. The correlation coefficient R2 value is found to be 0.999 for Amlodipine besylate and 0.999 for Indapamide. The LOD and LOQ values for Amlodipine besylate was found to be 0.00015 and 0.0005.The LOD and LOQ values for Indapamide was found to be 0.00028 and 0.00095 respectively. The proposed method was validated as per ICH guidelines with parameters like linearity, accuracy, Interday and precision, LOD, LOQ, robustness.

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