Section 74A(5) in The Drugs and Cosmetics Rules, 1945
(5)[ The licensee shall maintain reference samples from each batch of the drugs manufactured by him in a quantity which is at least twice the quantity of the drug required to conduct all the tests performed on the batch. In case of drugs bearing an expiry date on the label the reference samples shall be maintained for a period of three months beyond the date of expiry of potency. In case of drugs where no date of expiry of potency is specified on the label, the reference samples shall be maintained for a period of three years from the date of manufacture.] [Inserted by G.S.R. 444, dated 31.3.1973 (w.e.f. 28.4.1973).]