Development of a capillary zone electrophoresis assay to examine the disposition of [D-pen2,5]enkephalin in rats.
A novel capillary zone electrophoresis (CZE) assay method was developed to evaluate the systemic disposition of [D-pen2,5]enkephalin (DPDPE) in rats. DPDPE was recovered from serum samples (200 microliters) by solid-phase extraction. Complete resolution of DPDPE and the internal standard ([D-ser2]leucine-enkephalin; DSLET) from other serum components was achieved within 15 min on a 50-microns I.D. capillary column with borate buffer (25 mM, pH 8.3). The peak-height ratio (DPDPE to DSLET) was linear through 100 micrograms/ml, with a detection limit of 250 ng/ml in serum, when absorbance of the column eluent was monitored at 210 nm. Serum samples obtained from rats after a 10 mg/kg intravenous bolus dose of DPDPE were analyzed with the present CZE method. The results suggest that CZE is a useful technique for quantitating therapeutic peptides in biological matrices.
Chen
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Division of Pharmaceutics, School of Pharmacy, University of North Carolina at Chapel Hill 27599-7360, USA.
Pollack
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D000097:Acetonitriles; D000700:Analgesics / Q000097:blood*; D000818:Animals; D002021:Buffers; D011232:Chemical Precipitation; D019075:Electrophoresis, Capillary / Q000379:methods*; D020881:Enkephalin, D-Penicillamine (2,5)-; D004745:Enkephalins / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D006863:Hydrogen-Ion Concentration; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results
D000097:Acetonitriles; D000700:Analgesics; D002021:Buffers; D004745:Enkephalins; D020881:Enkephalin, D-Penicillamine (2,5)-; C032159:acetonitrile