Ij. Bosman et al., A SEMIAUTOMATED SOLID-PHASE EXTRACTION AND RADIORECEPTOR ASSAY FOR THE ANALYSIS OF SCOPOLAMINE IN URINE AND PLASMA, European journal of pharmaceutical sciences, 5(6), 1997, pp. 315-325
In a double-blind placebo-controlled cross-over study, we evaluated th
e therapeutic efficacy of transdermal scopolamine in ten patients with
reversible airways obstruction. They received a patch (Scopoderm(R) T
TS) behind the ear for three days and samples of blood and urine were
taken. A highly sensitive method was developed and validated to measur
e the low levels of free and total scopolamine in urine and plasma. Th
e procedure consisted of a semi-automated solid-phase extraction follo
wed by the analysis using radioreceptor assays. The mean plasma concen
trations, taken every third patch day, of free and total scopolamine w
ere 43.6 pg/ml and 229.0 pg/ml, respectively. In 24-h urine, collected
every second patch day, 6.3 mu g of free scopolamine and 83.4 mu g to
tal scopolamine was excreted. This means that 70% of the delivered dos
e (120 mu g in 24 h) is excreted in urine. For urine samples, the limi
t of detection (LOD) of the assay is 550 pg/ml and the limit of quanti
tation (LOQ) is 610 pg/ml. For plasma samples, the LOD is 16 pg/ml and
the LOQ is 38 pg/ml. (C) 1997 Elsevier Science B.V.