FDCs are classified in 4 categories with specific regulatory requirements

Can a co-investigator sign on the“principal investigator’s statement” in the protocol and “undertaking by the investigator” in the absence of principal investigator in BA/BE studies? Can a co-investigator conduct protocol meeting and assign duties to all staff and conduct the study in the absence of principal investigator in BA/BE studies without attending protocol training by principal investigator?

A co-investigator's role is that of a person working under guidance of an investigator. In fact, ICG GCP does not use the term co-investigator. Hence, he/she can not (1) sign investigator undertaking, (2) protocol signature page and (3) conduct protocol meeting and assign duties. Relevant definitions/excerpts are cited below:

Schedule Y 'undertaking by the investigator' has to be signed by the investigator whose name would appear in item one of the undertaking:

Co-Investigator/Sub-Investigator - A person legally qualified to be an investigator, to whom the Investigator delegates a part of his responsibilities.

ICH GCP 1.56 Sub-investigator - Any individual member of the clinical trial team designated and supervised by the investigator at a trial site to perform critical trial-related procedures and/or to make important trial-related decisions (e.g., associates, residents, research fellows).

Investigator
A person responsible for the conduct of the study at the trial site. Investigator is responsible for the rights, health and welfare of the study subjects. In case the study is conducted by a team of investigators at the study site then the designated leader of the team should be the principal investigator.

Indian GCP 3.3.5.Compliance with the protocol
The investigator/institution must agree and sign the protocol and / or another legally acceptable document with the sponsor, mentioning the agreement with the protocol, and confirm in writing that he/she has read and understood the protocol, GCPs and SOPs and will work as stipulated in them

3.3.3 Investigator should ensure that all persons involved in the study are adequately informed about the protocol, SOPs, the investigational product(s) and their study related duties and functions

ICH GCP 4.1.5 The investigator should maintain a list of appropriately qualified persons to whom the investigator has delegated significant trial-related duties

Can an impartial witness sign and date (and be present) on ICFs for all subjects in a day? Is there a guideline (global and local) on this mentioning on the maximum number of subjects that an impartial witness can be present for?

Having an impartial witness is an ethical requirement. No regulations clarify the questions you have asked.

It would be important to consider the following issues:

1. Does this meet ethical requirement
2. Does the approach protect rights, safety and well being in the subject and
3. What would be audit / inspection observations in each case?

The question from an auditor/inspector would be why a witness signed   for all subjects. Did he/she do this out of some personal benefit? It would be difficult to establish that the witness was truly impartial. This would not be acceptable.

Are there any regulations that prevent us from exporting HIV infected lab samples out of India?

ICMR has guidance on transfer of human biological material for commercial purposes and/or research for development of commercial products. This includes infectious material.

We are planning to conduct a study on FDCs (3 arms) of drugs already available in the market to compare their safety, efficacy and effect on a change in baseline condition. Does this study require DCGI approval? If DCGI approval is not required, is there any need to submit the SAEs (if any) to DCGI office?

FDCs are classified into 4 categories, for which there are specific regulatory requirements.

Category I - One or more active pharmaceutical ingredient(s) of the FDC is a new drug (as per Rule 122E of D&C Rules 1945) not approved in India.

Category II - All active pharmaceutical ingredients are approved/marketed in India individually and the FDC is proposed for marketing

Category III FDC - Marketed in India but some changes are sought

Category IV - Subsequent approvals after the approval of primary applicant’s FDC

If the FDC does not fall into any of the above categories, then FDC trials can be done without CDSCO approval.

As the FDC is marketed, the sponsor needs to comply with post-marketing requirements of reporting SAEs to CDSCO.