title: Liquid chromatographic determination of irbesartan in human plasma.
abstract: A simple and sensitive method was developed for determination of irbesartan by liquid chromatography with fluorescence detection. Irbesartan and losartan (I.S.) in human plasma were extracted using diethyl ether:dichloromethane (7:3, v/v) followed by back extraction with 0.05 M sodium hydroxide. Neutralized samples were analyzed using 0.01 M potassium dihydrogen phosphate buffer (containing 0.07% triethylamine as peak modifier, pH was adjusted with orthophosphoric acid to pH 3.0) and acetonitrile (66:34, v/v). Chromatographic separation was achieved on an ODS-C-18 column (100 mm x 4.6 mm i.d., particle size 5 microm) using isocratic elution (at flow rate 1.25 ml/min). The peak was detected using a fluorescence detector set at Ex 259 nm and Em 385 nm, and the total time for a chromatographic separation was approximately 13 min. The validated quantitation ranges of this method were 15-4000 ng/ml with coefficients of variation between 0.75 and 12.53%. Mean recoveries were 73.3-77.1% with coefficients of variation of 3.7-6.3%. The between- and within-batch precision were 0.4-2.2% and 0.9-6.2%, respectively. The between- and within-batch relative errors (bias) were (-5.5) to 0.9% and (-0.6) to 6.9%, respectively. Stability of irbesartan in plasma was >89%, with no evidence of degradation during sample processing and 60 days storage in a deep freezer at -70 degrees C. This validated method is sensitive and simple with between-batch precision of <3% and can be used for pharmacokinetic studies.
authors.affiliation: Department of Medicinal and Pharmaceutical Chemistry, Faculty of Pharmacy and Medical Sciences, Amman University, P.O. Box 263, Amman 19328, Jordan. ashokshakya@hotmail.com
authors.forename: Ashok K
authors.initials: AK
authors.lastname: Shakya
authors.forename: Yusuf M
authors.initials: YM
authors.lastname: Al-Hiari
authors.forename: Omran M O
authors.initials: OM
authors.lastname: Alhamami
mesh_terms: D001713:Biphenyl Compounds / Q000097:blood* / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D004986:Ether / Q000737:chemistry; D005615:Freezing; D006801:Humans; D000077405:Irbesartan; D019808:Losartan / Q000097:blood / Q000737:chemistry; D008752:Methylene Chloride / Q000737:chemistry; D015394:Molecular Structure; D015203:Reproducibility of Results; D012972:Sodium Hydroxide / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods; D013777:Tetrazoles / Q000097:blood* / Q000737:chemistry
chemical_list: D001713:Biphenyl Compounds; D013777:Tetrazoles; D004986:Ether; D012972:Sodium Hydroxide; D008752:Methylene Chloride; D000077405:Irbesartan; D019808:Losartan