At present, the treatment of human diseases with the former drug is a very wide phenomenon in the pharmaceutical industry. The former drug, also known as the prodrug, is first introduced by the drug chemist Albert in 1958, describing the prodrug as a compound that undergoes biological transformation before presenting a pharmacological action “. It can overcome some undesirable properties, such as poor absorption, biodegradation and preparation of some bioactive compounds. However, it should also be noted that a large number of new difficulties, especially in the evaluation of pharmacological, toxicological and clinical properties, will produce, such as the problem of prodrug bioequivalence.
We intend to discuss the following aspects.
Determination of the prodrug is preferred
The prodrug, although metabolites have the pharmacological activity, but if prodrug is released from the preparation and absorbed. At the same time, the determination method is reliable, then the best way shall still is the bioequivalence with the prototype drug (prodrug) to evaluate the two drugs.
Simultaneous determination of the prodrug and its metabolites
It is rarely considered the simultaneous determination of prototype drug and metabolite levels to evaluate the bioequivalence, but in some cases, for example, the drug itself is inactive prodrug, which in vivo can quickly transforms into active metabolites, and efficacy or toxicity mainly relates to the metabolites. So, metabolite determination also has important reference value in the bioequvalence decision making, and it can reduce the risk of consumers to replace the use of drugs by increasing the bioequvalence characteristic parameters of the metabolites.
Determination of metabolites
In some cases, some of the drug themselves are inactive prodrugs. But due to some reasons, for example, prodrug is not stable in a biological matrix; rapid metabolism and analysis method studies have difficulties; we can not determine the prototype drug in biological samples. Or when pharmaceutical active metabolites are closely related to drug efficacy and safety, it is generally thought to use the method for the determination of biological samples in the corresponding active metabolites to do bioequivalence trial.
Problems should be paid attention to in the detection
Consideration of the prodrug or metabolite as the detection index
Quality control of reference materials