(1/3191) The gas-liquid chromatograph and the electron capture detection in equine drug testing.
Three gas-liquid chromatographic (G.L.C.) procedures discussed have been designed around the four "esses" of detection tests--speed, sensitivity, simplicity, and specificity. These techniques are admirably applicable to the very low plasma drug levels encountered in blood testing under pre-race conditions. The methods are equally applicable to post-race testing procedures, where both blood and urine samples are tested. Drugs can only rarely be detected by the electron capture detector (E.C.D.) without a prior derivatization step, which conveys to the drug(s) high electron affinity. Because of broad applicability, two derivatizing agents, heptafluorobutyric (HFBA) and pentafluorpropionic (PFPA) anhydrides are employed. The three techniques, allowing broad coverage of various drug classes are: 1) direct derivatization of drugs to form strongly electron capturing amides and esters. 2) reductive fragmentation of drugs with lithium aluminum hydride to form alcohols, with conversion to ester derivatives. 3) oxidative fragmentation of drugs with potassium dichromate to form derivatizable groups, followed by direct derivatization. (+info)
(2/3191) Report on use of XAD resins in racing chemistry.
This report comprises a summary of the work done with XAD resin extraction by racing chemists and reported in the Association of Official Racing Chemists publications. It is apparent that the use of XAD resins is becoming more popular in racing laboratories as a technique for routine screening and also for the extraction of certain conjugated drugs. Most laboratories employ variations on the original Brinkmann Drug-Skreen Technique. Comparisons of the efficiency of extraction of drugs from horse urine by XAD-2 resin and by chloroform column extraction indicate that some drugs can be extracted with equal or greater efficiency by the resin technique. (+info)
(3/3191) Racing problems in the U.S.A.
The major problems of racing in the United States at the present time are caused by too much racing. This has led to too few horses and small fields. Consequently many owners and trainers are trying to enter their horses too frequently and to race them when they are not really fit to run. The desire to race horses as frequently as possible has led to constant pressure from horsemen through their organizations for so called "permissive medication". Started in the state of Colorado approximately ten years ago this has grown until finally there are only a few states, notably New York and New Jersey that have resisted the pressure. The drug that gave the opening wedge to permissive medication was phenylbutazone, but this in many states has led to the inclusion of other drugs including analgesics and drugs that veterinarians claim are needed for therapeutic purposes. Some states have endeavoured to control phenylbutazone medication by quantitation and while lower limits cause little difficulty, maximum allowable limits have caused problems and are not practical. While there has been no publicity to my knowledge about frusemide (furosemide, lasix) the abuse of this drug for so called "bleeders" is an example that may seriously interfere with drug detection in urine and its use should be confined to proven "bleeders" (i.e. horses suffering from epistaxis). Pre-race blood testing began roughly ten years ago at the harness tracks and has been resisted by our flat tracks rather successfully up to the present time. The blood testing methods and those used by the same laboratories in post-race urine testing is inadequate and will not detect many illegal drugs. (+info)
(4/3191) Doping control in Japan. An automated extraction procedure for the doping test.
Horse racing in Japan consists of two systems, the National (10 racecourses) and the Regional public racing (32 racecourses) having about 2,500 racing meetings in total per year. Urine or saliva samples for dope testing are collected by the officials from thw winner, second and third, and transported to the laboratory in a frozen state. In 1975, 76, 117 samples were analyzed by this laboratory. The laboratory provides the following four methods of analysis, which are variously combined by request. (1) Method for detection of drugs extracted by chloroform from alkalinized sample. (2) Methods for detection of camphor and its derivatives. (3) Method for detection of barbiturates. (4) Method for detection of ethanol. These methods consist of screening, mainly by thin layer chromatography and confirmatory tests using ultra violet spectrophotometry, gas chromatography and mass spectrometry combined with gas chromatography. In the screening test of doping drugs, alkalinized samples are extracted with chloroform. In order to automate the extraction procedure, the authors contrived a new automatic extractor. They also devised a means of pH adjustment of horse urine by using buffer solution and an efficient mechanism of evaporation of organic solvent. Analytical data obtained by the automatic extractor are presented in this paper. In 1972, we started research work to automate the extraction procedure in method (1) above, and the Automatic Extractor has been in use in routine work since last July. One hundred and twnety samples per hour are extracted automatically by three automatic extractors. The analytical data using this apparatus is presented below. (+info)
(5/3191) The antidoping control in horseraces in Italy.
The results and the improvement of the analytical procedures adopted for the control of doping in horses will be reported. This control has been systematically carried out in Italy for about 10 years in the laboratories of Italian Federation of Sport and Medicine in which the biological samples for the control of doping in various sport activities (football, cycling, athletics etc.) are also examined. In this way it is possible to use the same instruments for all these similar problems and compare the results. The analytical procedure is based on the following steps: 1) Extraction of the samples (mainly urine but sometimes blood or saliva). 2) Screening tests by thin-layer chromatography. 3) Confirmatory tests by gas chromatography on different columns and also by gas chromatography coupled with mass spectrometry. These single steps will be separately discussed, and practical problems encountered will be presented. (+info)
(6/3191) Less common "doping" agents and substances encountered during routine screening for drugs.
The chromatographic and spectroscopic properties of several unusual substances which have been detected in the "alkaloidal" chloroform extract from racehorse urine and saliva samples are reported. Some of these substances have been identified by combined gas chromatography-mass spectrometry and the source of the substance is stated where this is known. Other substances whose identity is not known have been detected and their mass spectra show characteristic amine fragments. The occurrence of these unidentified substances is more frequent in aged urine samples and it would therefore appear that they are associated with putrefaction. (+info)
(7/3191) Does the availability of prescribed drugs affect rates of self poisoning?
The trends in self-poisoning rates and in rates of prescribing of the major drug groups were compared. Over the period 1981-91, barbiturate prescribing and self poisoning both fell by 80%; for antidepressants, prescribing increased by over 40% and self poisoning by 30%; for antipsychotics, both rose by 30%; for benzodiazepines, poisoning fell by 30% and prescribing by 20%. Even for analgesic drugs, which are also available over the counter, there was a correspondence between changes in self poisoning and prescribing. The availability of prescribed drugs is directly related to their use for self poisoning. Restricting the availability of these drugs is a possible preventative strategy, although further research on this is needed. (+info)
(8/3191) Drug-protein binding and blood-brain barrier permeability.
The permeability surface area (PS) product, an index of permeability of the blood-brain barrier (BBB), was measured by using the in situ perfusion method. In the cerebral circulation, the fraction of drug that permeates into the brain through the BBB is not only the unbound fraction but also the fraction dissociated from the protein in the perfusate. The sum of these two fractions, the apparent exchangeable fraction, was estimated by fitting the parameters of the BBB permeability under the condition of varying BSA concentrations in the perfusate. The unbound fraction of drugs in a buffer containing 0.5 mM BSA was measured by using the ultrafiltration method in vitro, and the apparent exchangeable fraction was measured in vivo by using the intracarotid artery injection method. The apparent exchange fraction was 100% for S-8510, 96.5% for diazepam, 90.9% for caffeine, 38.3% for S-312-d, 33.1% for propranolol, and 6.68% for (+)-S-145 Na, and each of these was higher than the corresponding unbound fraction in vitro in all drugs. The apparent exchangeable fractions, for example, were 8 times higher for diazepam and 38 times for S-312-d than the unbound fractions in vitro. The apparent exchangeable fraction of drugs was also estimated from the parameters obtained with the perfusion method. Because drugs can be infused for an arbitrary length of time in the perfusion method, substances with low permeability can be measured. The apparent exchangeable fractions obtained with this method were almost the same as those obtained with the intracarotid artery injection method. (+info)