1.  Used in a shop, or belonging to it. Johnson. [1913 Webster]

2.  Kept in stock by apothecaries; -- said of such drugs and medicines as may be obtained without special preparation or compounding; not magistral. [1913 Webster]

officinal, adj.
1 a (of a medicine) kept ready for immediate dispensing. b made from the pharmacopoeia recipe (cf. MAGISTRAL). c (of a name) adopted in the pharmacopoeia.
2 (of a herb or drug) used in medicine.

Derivative:
officinally adv.

Etymology:
med.L officinalis f. L officina workshop