Residues of Sedative Drugs

Stability studies have shown azaperone to be quite stable upon heating. When samples of kidney, liver, bacon, and injection sites from pigs treated with azaperone were heat-pasteurized, no losses of the concentrations of the parent dmg and its main metabolite, azaperol, occurred (107). 

The stability of diazepam and its metabolites (oxazepam, temazepam, and demeth-yldiazepam) when present in liver of treated bulls has been studied (108). Following boiling in water for 1 h, the oxazepam metabolite was the most unstable of the compounds studied, being degraded to an extent of approximately 50%. The parent drug and the other metabolites were more stable they were all present, after treatment, at levels corresponding to 79-89% of the initial concentrations. 

Residue-testing laboratories might also need to review their sample preparation processes and consider modifying or eliminating tissue homogenization prior to residue extraction. Suppliers of proficiency-testing services should also question whether certain drugs are appropriate to include in such studies. For example, liver spiked with sulfaquinoxaline, sulfadiazine, or sulfamerazine is not suitable for preparation of spiked interlaboratory check samples or reference materials. 

van Schothorst, in Antibiotic Residues in Slaughter Animals, Thesis, University of Utrecht, The Netherlands (1969). 

Soares, J.O. Fernandes, M.L. Bastos, and M. Feireira, in Residues of Veterinary Drugs in Food, Proc. Euroresidue II Conf., Veldhoven. May 3-5, 1993 (N. Haagsma, A. Ruiter, and P.B. Czedik-Eysenberg, Eds.). Fac. Vet. Med., Univ. Utrecht, The Netherlands, p. 246 (1993). 

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