Section 20(e) in The Assam Dangerous Drugs Rules, 1937
(e)A licensed chemist shall not serve dangerous medicinal drugs other than coca leaves and coca derivatives more than once on the same prescription, unless it bears superscription by the approved practitioner, who prescribed it, stating that it is to be repeated and the intervals of time after which and the number of times (not exceeding three) that is to be repeated. In the absence of such a superscription, the prescription shall be retained by the licensed chemist after it has been served once.
