Differences in binding affinities of MDA, MDMA, MDEA, Amphetamine, Methamphetamine, and their deuterated analogues to solid-phase extraction cartridges.

This study evaluated the potential for partial separation of drugs from their deuterated internal standards using Cerex(®) Polycrom™ CLIN II solid-phase extraction (SPE) cartridges. After elution from the column and derivatization, gas chromatography-mass spectrometry results showed that the target compound eluted from the SPE cartridge prior to its deuterated form. This elution separation effect was greater for 3,4-methylenedioxymethamphetamine (MDMA) and methamphetamine (MAMP) than for the other drugs studied. When the drugs were eluted in 0.5 mL increments from a 50 mg sorbent bed, no drug appeared in the first fraction. The drug to internal standard ratios (expected value 1.00) for subsequent fractions collected were 1.30, 1.07, and 0.83 for MDA/MDA-d(5); 1.65, 1.18, 0.67, and 0.56 for MDMA/MDMAd(5); and 1.37, 1.18, and 0.95 for MDEA/MDEA-d(6). For d-AMP and d-MAMP, the expected ratio was 0.40. The subsequent ratios were 0.63, 0.46, 0.35, and 0.34 for d-AMP/d-AMP-d(11); and 1.00, 0.59, 0.25, and 0.18 for d-MAMP/d-MAMP-d(14). The affinity of d-MAMPd(14) was shown to be greater than that of d-MAMP-d(5), and deuteration at the propyl end of the molecule was shown to increase binding more than deuteration on the phenyl group.

Stability of fluconazole in injectable solutions.

The stability of fluconazole 1 mg/mL in several injectable solutions at 25 degrees C over 72 hours was studied. Fluconazole 2 mg/mL was mixed in a 1:1 ratio with 5% dextrose injection, lactated Ringer's injection, potassium chloride 20 meq/L in 5% dextrose injection, heparin sodium 100 units/mL in 5% dextrose injection, theophylline 0.8 mg/mL in 5% dextrose injection, and morphine sulfate 0.5 mg/mL in 5% dextrose injection. Three 1-mL samples were taken from each admixture at 0, 6, 12, 24, 36, 48, and 72 hours and analyzed for fluconazole concentration by stability-indicating gas chromatography. Fluconazole 2 mg/mL was stable in potassium chloride plus 5% dextrose injection and in theophylline plus 5% dextrose injection for 72 hours. Fluconazole was stable in the other injectable solutions for 24 hours. The stability of theophylline, heparin, or morphine sulfate in the presence of fluconazole was not studied. Fluconazole was stable in potassium chloride 20 meq/L plus 5% dextrose injection and in theophylline 0.8 mg/mL plus 5% dextrose injection for 72 hours and stable in the other injectable solutions for 24 hours.