Drug discrimination study method

An alternative method of assessing interoceptive drug effects is the behavioral drug discrimination procedure, which relies on observable behavioral responses to determine whether a drug s stimulus effects have been perceived by the subject (Preston 1991 Overton 1991). Behavioral drug discrimination is widely used in animal studies (Holtzman 1990 see chapter by Stolerman, this volume) because it... 

Although multidimensional separation generally offers enhanced selectivity and discrimination of solutes, application of more than one hyphenated techniques is usually required for complete and unequivocal identification of the analytes. A recent report states that two widespread misconceptions about mass spectroscopy (MS) are that GC-MS is a specific method and tlrat GC-MS is 100% accurate (5). The 1989 Forensic Urine Drug Confirmation Study by the American Association for Clinical Chemistry/College of American Pathologists confirmed this concern about overreliance on GC-MS as a confirmation method (5). 

The drug discrimination method has also been applied to study anxiolytic drugs using pentylenetetrazol at subconvulsive doses (Sherman and Lai 1979, 1980 Sherman et al. 1979 Lai and Sherman 1980). 

Two methods of learning about drug effects are drug discrimination and conflict paradigm studies. 

It should be noted however that it is almost impossible to predict fully the in vivo dissolution rate due to the many factors involved, of which several have not yet been completely characterized. The introduction of new study techniques to directly follow drug dissolution in vivo in the human intestine should therefore be of importance [30, 31]. For example, in vivo dissolution studies discriminated between the dissolution rates of the two different particle sizes of spironolactone, based on the intestinal perfusate samples. In addition, dissolution rates of carba-mazepine obtained in vitro were significantly slower than the direct in vivo measurements obtained using the perfusion method. The higher in vivo dissolution rate was probably due to the efficient sink conditions provided by the high permeability of carbamazepine [30, 31]. 

The interaction between drugs in the lumen and intestinal components is generally a poorly studied area, and it is difficult based on in vivo data to discriminate such effects from other factors affecting absorption. In addition, evidence for the in vivo relevance of available in vitro methods is sparse. 

The techniques of ESR were used [10] to study radicals formed in solid state. ESR proved to be a very sensitive technique to detect radicals (10" ° mol 1 ) trapped for days, weeks and even years and discriminate between irradiated and non-irradiated drugs. Radical amounts increased linearly with absorbed doses up to 10 kGy, the radiolytic yield was constant, and ESR post-dosimetry was proposed as a new method to identify radiosterilized drugs [11]. Thermoluminescent signals are present prior to any irradiation in all the 3-lactam drugs tested [12]. The irradiated drugs showed a modification in the quality and quantity of the thermoluminescent temperature peaks. 

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