title: Improved analytical validation and pharmacokinetics of valsartan using HPLC with UV detection.
abstract: The primary objective of the study was to validate a simple and sensitive method of determining valsartan concentration in human plasma samples using high performance liquid chromatography (HPLC) combined with ultraviolet (UV) detection. Methanol appeared to be the best with a high recovery efficiency compared to other solvents such as acetonitrile, ethylacetate and methyl-tert-butyl ether. After a simple protein precipitation using methanol, the analytes were separated on a Phenomenex Luna C(18) column using 42% acetonitrile with 15 mM potassium dihydrogenphosphate in water (pH 2.0; adjusted with phosphoric acid) as the mobile phase at a flow rate of 1.2 mL/min. The standard calibration curve constructed in the concentration range of 50-2000 ng/mL showed good linearity (r(2)>0.9997). Spironolactone was used as an internal standard (IS). Valsartan and IS eluted at 10.25 and 12.17 min, respectively. The intra-day and inter-day precision and accuracy were satisfactory with relative standard deviations of less than 15%. No interference peaks or matrix effects were observed in human plasma. Valsartan concentration in human plasma was well established following a single 80 mg oral dose (Diovan capsule) to eight healthy volunteers. The current determination of valsartan concentration by protein precipitation using methanol followed by analysis using HPLC with UV detection was rapid and sensitive, and provide an alternative to the analysis of valsartan by studying its clinical applications.
authors.affiliation: National Research Lab. for Bioavailability Control, College of Pharmacy, Kangwon National University, Chuncheon 200-701, Korea.
authors.forename: Zong-Zhu
authors.initials: ZZ
authors.lastname: Piao
authors.forename: Eung-Seok
authors.initials: ES
authors.lastname: Lee
authors.forename: Huyen Thi Thanh
authors.initials: HT
authors.lastname: Tran
authors.forename: Beom-Jin
authors.initials: BJ
authors.lastname: Lee
mesh_terms: D000328:Adult; D047228:Angiotensin II Type 1 Receptor Blockers / Q000032:analysis* / Q000493:pharmacokinetics*; D001798:Blood Proteins / Q000378:metabolism; D002138:Calibration; D002214:Capsules; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D008297:Male; D011485:Protein Binding; D012015:Reference Standards; D015203:Reproducibility of Results; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D013777:Tetrazoles / Q000032:analysis* / Q000493:pharmacokinetics*; D014633:Valine / Q000031:analogs & derivatives* / Q000032:analysis / Q000493:pharmacokinetics; D000068756:Valsartan
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D001798:Blood Proteins; D002214:Capsules; D012997:Solvents; D013777:Tetrazoles; D000068756:Valsartan; D014633:Valine