No abstract

Methods suitable for the demonstration of amygdalin are presented; including an indirect determination (measurement of enzymatically derived benzaldehyde) and several direct methodologies (GC/MS, HPLC, or TLC). Reagents and equipment commonly found in a forensic toxicology laboratory were employed.

A microprocessor-controlled, automated extraction/concentration device, the Prep 1 (Du Pont Clinical Systems), was evaluated for application to the isolation of drug substances from postmortem fluids and tissue homogenates. Two classes of materials were investigated: barbiturates and the benzodiazepine, diazepam. With as little as 200 mg of tissue, barbiturate derivatives were successfully isolated and measured by gas chromatography using nitrogen-phosphorus detection with a coefficient of variation of 2 to 5%. Diazepam was measured in a similar fashion with a coefficient of variation of 4.4%. Preliminary investigation indicates that this system is applicable to a wide range of drug substances of toxicological interest.

Clinical anecdotal reports have indicated a probably additive and/or synergistic response to the co-ingestion of ethyl alcohol and methadone. This study investigated the possible explanations for this observations, which may be associated with alterations of the plasma concentration dynamics of methadone and alcohol in the rat. Plasma concentrations of ethanol, methadone or both were followed over an eight hour period following substance administration. GC/FID and GC/MS were employed to quantify ethanol and methadone, respectively. The results of this study indicated that ethyl alcohol significantly increased peak methadone concentrations. Further, methadone significantly depressed late alcohol elimination.

No abstract

A method is described for the estimation of basic drugs and metabolites in post mortem tissues and fluids. The method is based upon the selective extraction of these substances, differential weak acid cleanup, and the final preparation of a microextract that is compatible with the rubidium source found in most nitrogen-phosphorous detectors (NPD). Application of this extract to gas chromatography/NPD allows for the measurement of common basic drugs at subtherapeutic, therapeutic, and toxic concentrations in a variety of tissue matrices (liver, brain, lung, heart, and kidney) using a minimum of sample (less than one gram). Internal standards are used to allow for the quantitative as well as qualitative aspects of the assay. Examples of tissue extract chromatograms containing commonly encountered basic drugs are presented along with precision data.

No abstract

In a continuation of work previously reported involving the comparative kinetics of digoxin in vitreous humor and serum after an intravenous dose, the present report describes the pharmacokinetics of digoxin in this model following the administration of a single oral dose. Serum and vitreous humor concentrations of digoxin were monitored by radioimmunoassay for 720 min after a single oral dose of 0.1 mg digoxin/kg. Serum concentrations peaked by 60 min and declined over the remaining observation period with a half-life of 360 min. Vitreous humor concentrations lagged behind the serum concentrations, peaked between 60 and 120 min, and then declined at a rate less than that of serum with convergence of concentration occurring in the 720-min samples. The vitreous humor-serum ratios ranged from a low of 0.003 (15 min) to a high of 0.98 at convergence. The impact of these findings upon forensic toxicologic practice is reviewed.