AUTOMATED GAS-CHROMATOGRAPHIC ASSAY FOR AMLODIPINE IN PLASMA AND GINGIVAL CREVICULAR FLUID

This paper describes an automated capillary gas chromatographic method for the determination of amlodipine in plasma, and in sub-microlitre volumes of gingival crevicular fluid (GCF), in order to assess if amlo dipine is present in GCF under conditions of gingival overgrowth, as h as been shown for nifedipine, another dihydropyridine drug. Liquid-liq uid extraction followed by derivatisation was employed to isolate amlo dipine and render it suitable for gas chromatography. Amlodipine was a nalysed in plasma and GCF of four patients undergoing amlodipine thera py for cardiovascular disorders, three of whom had significant gingiva l overgrowth. Amlodipine was detected in the plasma of ail patients an d in massive concentrations in the GCF of those patients with overgrow th, 23- to 290-fold greater than in their plasma. Like nifedipine, aml odipine sequestration into GCF appears to be linked with gingival over growth.