HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF DILTIAZEM AND 2 OF ITS METABOLITES IN PLASMA USING A SHORT ALKYL CHAIN SILANOL DEACTIVATED COLUMN
Dr. Rutledge et al., HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC DETERMINATION OF DILTIAZEM AND 2 OF ITS METABOLITES IN PLASMA USING A SHORT ALKYL CHAIN SILANOL DEACTIVATED COLUMN, Journal of chromatography. Biomedical applications, 615(1), 1993, pp. 111-116
A simple and reproducible method for the determination of diltiazem an
d its two major metabolites, demethyl- and deacetyldiltiazem, is prese
nted using a new column containing a short alkyl chain silanol deactiv
ated support. This method involves the extraction of alkalinized plasm
a with a hexane-isopropanol mixture (95:5, v/v) followed by back-extra
ction into 5 mM sulfuric acid. Reversed-phase liquid chromatography is
used with ultraviolet detection at 237 nm over a concentration range
of 20-400 ng/ml for the compounds. Imipramine is used as the internal
standard. Within-day and between-day coefficients of variation are les
s than 10%. The lower limits of detection are 4, 2 and 4 ng/ml for dil
tiazem, deacetyl- and demethyldiltiazem, respectively. Samples can be
stored for up to thirty days with no significant degradation. The assa
y has clinical applicability.