Quantitation of iptakalim in human plasma by high-performance liquid chromatography–tandem mass spectrometry

Teng, Guosheng; Wang, Yingwu; Tang, Yaning; Wang, Rui; Fang, Yi; Fawcett, J. Paul; Gu, Jingkai

doi:10.1016/j.jchromb.2007.09.019

Cited by 4 publications

(2 citation statements)

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“…If taken with a high-fat meal absorption is reduced. 1 The majority of the methods were developed for quantification of sildenafil alone from pharmaceutical, 11,16 biological samples 9,10,[12][13][14][15][17][18][19]22 and ayurvedic products 20 by using LC-MS/ MS, [9][10][11][12][13][14][15][16][17][18][19][20] capillary electrophoresis 21 and ion mobility spectrophotometry. 22 A literature survey reveals that only a few methods were reported for quantification of sildenafil and its main metabolite N-desmethyl sildenafil from biological samples by LC-MS/MS, [2][3][4][5][6] capillary zone electrophorsis-ion trap mass spectrometry 7 and micellar electrokinetic capillary chromatography.…”

Section: Introductionmentioning

confidence: 99%

Sildenafil and N-desmethyl sildenafil quantification in human plasma by HPLC coupled with ESI-MS/MS detection: Application to bioequivalence study

et al. 2010

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The present study aims at developing a simple, sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous quantification of sildenafil and its metabolite N-desmethyl sildenafil in human plasma using sildenafil-d8, N-desmethyl sildenafil-d8 as internal standards (IS). Chromatographic separation was performed on Zorbax SB C18, 4.6 Â 75 mm, 3.5 mm column with an isocratic mobile phase composed of 10 mM ammonium acetate and acetonitrile (5/95 v/v), at a flow-rate of 0.6 ml min À1 . Sildenafil, sildenafil-d8, N-desmethyl sildenafil and N-desmethyl sildenafil-d8 were detected with proton adducts at m/z 475.2 / 283.4, 483.4 / 283.4, 461.3 / 283.4 and 469.4 / 283.4 in multiple reaction monitoring (MRM) positive mode respectively. Both drug, metabolite and internal standards were extracted by liquid-liquid extraction. The method was validated over a linear concentration range of 1.0-1000.0 ng ml À1 for sildenafil and 0.5-500.0 ng ml À1 for N-desmethyl sildenafil with correlation coefficient (r 2 ) $ 0.9998 for sildenafil and (r 2 ) $ 0.9987 for N-desmethyl sildenafil. This method demonstrated intra and inter-day precision within 1.5 to 5.1 and 2.2 to 3.4% for sildenafil and within 1.3 to 3.1 and 2.8 to 4.3% for N-desmethyl sildenafil. This method demonstrated intra and inter-day accuracy for sildenafil within 97.3 to 98.3 and 96.7 to 97.2% and for N-desmethyl sildenafil within 95.3 to 96.3 and 95.0 to 97.2%. Both analytes were found to be stable throughout three freeze/thaw cycles, bench top and postoperative stability studies. This method was used successfully for the analysis of plasma samples following oral administration of 100 mg in 43 healthy Indian male human volunteers under fasting conditions.

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Section: Introductionmentioning

confidence: 99%

Sildenafil and N-desmethyl sildenafil quantification in human plasma by HPLC coupled with ESI-MS/MS detection: Application to bioequivalence study

et al. 2010

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“…Urine sample were collected at 2, 4, 6, 8, 12, 24 and 36 h; the volume of urine for each period were recorded and 4 ml urine from each period was also stored at −80°C. The analytical method was based on liquid chomatography–tandem mass spectrometry (LC‐MS/MS) using sildenafil as internal standard [17] . Sample preparation involved liquid–liquid extraction with dichloromethane–diethyl ether (2 : 3, v/v) in a basic environment.…”

Section: Methodsmentioning

confidence: 99%