The efficacy of a drug or device is one of the criteria for market approval and is reviewed as part of the registration process. Different procedures can be used for different categories of drugs (e.g. generic products or new chemical entities).

Review and approval of products with long-established chemical entities

For products indicated for standard uses and containing established ingredients (such as most generic essential drugs), there is usually no need to re-evaluate the efficacy and safety of the active ingredients. Separate national clinical studies would not normally be required. Emphasis should be put on a review of other factors, for example the presentation, bioavailability (when indicated) and quality of the product, and the accuracy of the accompanying information. Requirements for the submission of documents for product registration, and for the process of registration, are set out in WHO guidelines on drug registration requirements.⁵⁴

Review and approval of products containing new chemical entities

Considerably more extensive information is required to support a marketing application for a new drug substance, in order to provide assurance of efficacy and safety. In particular, detailed accounts are required on chemistry, pharmacological properties, toxicological data, reproductive and teratological studies in animals, and clinical studies. Small regulatory authorities need to adopt caution in licensing newly developed products, because they are unlikely to have the capacity to undertake the multidisciplinary assessment applied to them within large, highly evolved authorities, or to monitor their performance in use through post-marketing surveillance. In general, a small authority with limited resources is best advised to wait until this information has been generated and assessed elsewhere before authorizing such a product for use.

Evaluation of traditional and herbal medicines

Improved use of traditional and herbal medicines can be achieved through adequate regulation²⁵ and through better evaluation of their safety and efficacy. WHO is involved in efforts to identify and document all published evidence on the pharmacology and clinical use of commonly used traditional and herbal medicines.²⁴ This information can support efforts to integrate traditional and herbal medicines into national health systems.

Authorization of clinical trials

A DRA may occasionally need to consider an application to conduct a clinical trial of an unregistered drug in the treatment of a condition that has high local prevalence. To allow for this contingency, the registration system should include provision for the importation of the necessary materials, subject to appropriate controls. Such trials should take place only after formal clearance has been obtained from the competent registration authority. Moreover, assurances must be obtained that trials will be conducted in conformity with the principles contained in the World Medical Association’s Declaration of Helsinki and the guidelines issued by the Council for International Organizations of Medical Sciences.⁵⁵ There is growing awareness that it is unethical to undertake clinical trials in developing of drugs that the participants will never be able to afford to continue after the trials have ended.⁵⁶ The revision of the Declaration of Helsinki in 2000 was in part prompted by such concerns.⁵⁷ (See also Chapter 10).