1) Materia medica 2) Pharmacological medicine 3) Pharmacology 
science of quantity or dosage
• (n.) The science or doctrine of doses; dosology.
<pharmacology, study> The science or doctrine of doses; dosology. ... Origin: Gr. How much: cf. F. Posologie. ... (04 Mar 1998) ... 
(po-sol´ә-je) the science of dosage or a system of dosage. adj., posolog´ic., adj.
Po·sol'o·gy noun [ Greek ... how much + -logy : confer French posologie .] (Medicine) The science or doctrine of doses; dosology. 
Type: Term Pronunciation: pō-sol′ŏ-jē Definitions: 1. The branch of pharmacology and therapeutics concerned with a determination of the doses of remedies; the science of dosage.
[n] - the pharmacological determination of appropriate doses of drugs and medicines
posology 1. The science of medical doses. 2. The science dealing with compilations of medical dosages. 3. The pharmacological determination of appropriate doses of drugs and medicines. 'Posology and method of administration' is found in other languages as: Italian: 'Posologia' French: 'Posologie, nature ...
noun the pharmacological determination of appropriate doses of drugs and medicines