|
| Studies | Aim of study | Time period |
|
| Preclinical studies | (i) Screening and testing in laboratory. | 1–10 years |
| (ii) Animal studies for the evaluation of the activity and toxicity of active agents. |
|
| Phase I clinical trials | (i) Early testing in small groups of 10–20 human volunteers. | 2-3 years |
| (ii) Confirming the lack of toxicity and the delivery of effective doses. |
|
| Phase II clinical trials | Larger phase II trials are done in many hundreds or up to a few thousands of volunteers to obtain effectiveness data for promising candidates. | 2–5 years |
|
| Phase III clinical trials | (i) To demonstrate effectiveness, safety, and acceptability in thousands of human volunteers involves large-scale testing. | 2–6 years |
| (ii) It is providing statistically significant data for review by regulatory agencies (e.g., the U.S. FDA or others) before new products can be approved for marketing and use. |
|
| Phase IV study | For microbicides, postmarketing surveillance might also include any long-term effects on HIV disease progression and treatment (including possible selection of drug-resistant HIV when relevant), HIV risk behavior, and interactions with other diseases, therapies, or products. | Indefinitely |
|
| Other preapproval studies | (i) Data from additional studies are often required by regulatory agencies for the approval of new products. | 2–6 years |
| (ii) Regulatory agencies also require information regarding product manufacturing methods and quality control measures to ensure that the marketed product is the same as the tested product. |
|
| Product introduction and supporting studies | Addressing policy and logistical issues is often the key for the introduction of new health products. For microbicides, many countries will require preintroductory studies in their own populations before allowing the importation and distribution of a new product. | up to 10 years |
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