title: High-performance liquid chromatography method for the quantification of entacapone in human plasma.
abstract: A simple, sensitive and selective HPLC method with UV detection (315 nm) was developed and validated for quantitation of entacapone in human plasma, the newest addition to the group of antiparkinsonian agents. Following a single-step liquid-liquid extraction (LLE) with ethyl acetate/n-hexane (30/70, v/v), the analyte and internal standard (rofecoxib) were separated using an isocratic mobile phase of 30 mM phosphate buffer (pH 2.75)/acetonitrile (62/38, v/v) on a reverse phase C18 column. The lower limit of quantitation was 25 ng/mL, with a relative standard deviation of less than 8%. A linear range of 25-2500 ng/mL was established. This HPLC method was validated with between-batch and within-batch precision of 2.2-4.2% and 1.7-7.8%, respectively. The between-batch and within-batch accuracy was 98.7-107.5% and 97.5-106.0%, respectively. Frequently coadministered drugs did not interfere with the described methodology. Stability of entacapone in plasma was excellent, with no evidence of degradation during sample processing (autosampler) and 30 days storage in a freezer. This validated method is sensitive, simple and repeatable enough to be used in pharmacokinetic studies.
authors: Biopharmaceutical Research, Suven Life Sciences Ltd., Serene Chambers, Road #7, Banjara Hills, Hyderabad 500034, India. nvsrk@suven.com
authors: N V S
authors: NV
authors: Ramakrishna
authors: K N
authors: KN
authors: Vishwottam
authors: S
authors: S
authors: Wishu
authors: M
authors: M
authors: Koteshwara
authors: J
authors: J
authors: Chidambara
mesh_terms: D000284:Administration, Oral; D000978:Antiparkinson Agents / Q000097:blood* / Q000493:pharmacokinetics; D002396:Catechols / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D015394:Molecular Structure; D009570:Nitriles; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D000978:Antiparkinson Agents; D002396:Catechols; D009570:Nitriles; C071192:entacapone