title: Direct determination of stability of protease inhibitors in plasma by HPLC with automated column-switching.
abstract: Automated column-switching HPLC methods were developed and utilized for the direct analyses of three hydroxamic acid based metalloprotease inhibitors in rat plasma. These column-switching methods involved the use of a restricted-access media (RAM) precolumn and a column-switching valve, allowing the complete automation of sample preparation and HPLC. The plasma samples were directly injected onto a precolumn packed with SPS/ODS stationary phase and then backflushed onto an ODS analytical column using a 6-port column-switching device. The drug stability in rat plasma was determined using both the automated and traditional HPLC methods. The results obtained from the automated column-switching methods were in good agreement with those from traditional methods that involve sequential protein precipitation, liquid extraction, solvent evaporation, and sample reconstitution. In addition to the elimination of labor-intensive and time-consuming sample preparation procedures, the column-switching methods allowed on-line analyte enrichment and accurate determination of drug stability in plasma with detection limits in the range of 10-20 ng/ml(-1). This work represents, for the first time, a drug stability study in plasma by automated column-switching HPLC technique with the use of a RAM column. Our column-switching methods can be readily adapted to any existing HPLC system with minimal hardware modification.
authors.affiliation: The Procter & Gamble Company, Health Care Research Center, Mason, OH 45040, USA. pengsx@pg.com
authors.forename: S X
authors.initials: SX
authors.lastname: Peng
authors.forename: M J
authors.initials: MJ
authors.lastname: Strojnowski
authors.forename: D M
authors.initials: DM
authors.lastname: Bornes
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D004355:Drug Stability; D005069:Evaluation Studies as Topic; D006877:Hydroxamic Acids / Q000097:blood*; D061965:Matrix Metalloproteinase Inhibitors; D011480:Protease Inhibitors / Q000097:blood* / Q000737:chemistry; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D006877:Hydroxamic Acids; D061965:Matrix Metalloproteinase Inhibitors; C405206:PGE 4410186; C405205:PGE 9818266; D011480:Protease Inhibitors