Section 65(9)(b) in The Drugs and Cosmetics Rules, 1945
(b)The supply of drugs specified in [Schedule H and Schedule H1] [Substituted for the words "Schedule H" by Notification No. G.S.R. 588(E) dated 30.8.2013 (w.e.f. 21.12.1945)] or Schedule X to Registered Medical Practitioners, Hospitals, Dispensaries and Nursing Homes shall be made only against the signed order in writing which shall be preserved by the licensee for a period of two years.]