Section 21(1)(a): repealed (without coming into force), on 8 March 1985, by section 2 of the Medicines Amendment Act 1985 (1985 No 29).
Section 21(1)(ca): inserted, on 8 August 1990, by section 2 of the Medicines Amendment Act (No 2) 1990 (1990 No 97).
Section 21(4): amended, on 28 October 2021, by section 3 of the Secondary Legislation Act 2021 (2021 No 7).