Narcotic Drugs and Psychotropic Substances Act, 1985 – Section 8(c) – Psychotropic Substances – Buprenorphine Hydrochloride – Applicability of NDPS Act vis-à-vis Drugs and Cosmetics Act, 1940 – Retrospective Application of Judicial Precedent – Scope of Section 216 CrPC – Doctrine of Prospective Overruling – Article 20(1) of Constitution.