Solubility
Only where a special,quantitative solubility test is given in the individual monograph,and is designated by a test heading,is it a test for purity.
The approximate solubilities of Pharmacopeial and National Formulary substances are indicated by the descriptive terms in the accompanying table.The term “miscible”as used in this Pharmacopeia pertains to a substance that yields a homogeneous mixture when mixed in any proportion with the designated solvent.
| Descriptive Term |
Parts of Solvent Required for 1Part of Solute |
| Very soluble |
Less than 1 |
| Freely soluble |
From 1to 10 |
| Soluble |
From 10to 30 |
| Sparingly soluble |
From 30to 100 |
| Slightly soluble |
From 100to 1000 |
| Very slightly soluble |
From 1000to 10,000 |
Practically insoluble,or
Insoluble |
10,000and over |
Soluble Pharmacopeial and National Formulary articles,when brought into solution,may show traces of physical impurities,such as minute fragments of filter paper,fibers,and other particulate matter,unless limited or excluded by definite tests or other specifications in the individual monographs.