In an IND study, the specified dosage of an investigational product is 2 mg twice a day for 10 days. The product is available in 1 mg tablets. The…

The subject is instructed to take 2 mg twice a day. Since the tablets are 1 mg each, the subject must take 2 tablets per dose. With two doses per day, the total daily consumption is 4 tablets (2 tablets/dose x 2 doses/day). Over the 10-day treatment period, the total number of tablets to be consumed is 40 (4 tablets/day x 10 days). The subject was dispensed 45 tablets. Therefore, the number of tablets remaining after 10 days should be 5 (45 dispensed - 40 consumed). This calculation is a fundamental component of investigational product accountability required in clinical trials.

A. 0: This is incorrect as the subject was dispensed 45 tablets but was only instructed to take 40 over the specified period.

B. 1: This represents an incorrect calculation of the remaining tablets based on the prescribed dosage and duration.

D. 20: This represents the total number of 2 mg doses (2 doses/day 10 days), not the number of remaining 1 mg tablets.

1. U.S. Food and Drug Administration (FDA). Code of Federal Regulations Title 21, Part 312.62(a). This regulation mandates that an investigator maintain "adequate records of the disposition of the drug, including dates, quantity, and use by subjects." This directly implies the need for precise accounting of dispensed, used, and returned investigational products.

2. International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). (2016). Guideline for Good Clinical Practice E6(R2), Section 4.6.3. This section states, "The investigator/institution should maintain records of the product's delivery to the trial site, the inventory at the site, the use by each subject, and the return to the sponsor or alternative disposition of unused product(s)." This principle underpins the calculation in the question.

3. International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH). (2016). Guideline for Good Clinical Practice E6(R2), Section 5.14.3. This section outlines the sponsor's responsibility for implementing a system for retrieving investigational products and documenting this retrieval (e.g., for reconciliation). This reconciliation process requires accurate counts of returned medication.