(1993; 36 pages)
2.3. Therapeutic equivalence of multisource products
While the inclusion of dissolution requirements in The international pharmacopoeia was considered to be an important step forward, it was recognized that an in vitro dissolution test was only one stage in the procedure for ensuring that multisource products were therapeutically equivalent. Information on the interchangeability of conventional-release solid dosage forms from a wide range of sources, all containing the same quantity of the same active ingredient, was essential for those responsible for approving the registration of products.
It was recognized that existing national regulatory requirements varied with respect to multisource products and that a need therefore existed for global guidelines. It was suggested that WHO, among other appropriate activities, might:
- undertake a survey of national legislation and practices with regard to registration requirements, and the prescribing and dispensing in retail pharmacies of multisource products;
- compile and review at regular intervals a list of drug substances that may be associated with bioavailability problems (including those of narrow therapeutic index, etc.);
- collect and compile available information on the correlation between activity in vivo and in vitro for essential drugs presenting problems (reported, for example, via drug monitoring services) of bioavailability and bioequivalence;
- develop WHO guidelines for bioequivalence studies, in the context of the WHO guidelines on good clinical practices currently in course of preparation;
- establish a policy and recommendations with regard to the role of dissolution testing in the quality control of drugs and in determining whether they are therapeutically equivalent.