Other Nonaqueous Solutions
Water Miscible Cosolvent Systems are solutions of water and water
miscible solvents such as alcohol, glycerin, propylene glycol, polyethylene
glycol 400. These solvent mixtures are used to improve the solubility of
poorly soluble organic substances, and may be formulated for oral, topical,
or parenteral administration. e.g. Phenytoin Inj.
Glycerins or Glycerites are solutions in composed of no less
than 50% glycerin by weight. They are extremely viscous and are rarely
used in practice and are generally limited to use in topical products,
e.g. Glycerin Otic Solution.
Collodions are liquid preparations containing nitrocellulose
pyroxylin in a mixture of ethanol and ethyl ether. They are used as topical
protectives or as a topical drug vehicle. They are made "flexible"
by the addition of castor oil, e.g. Flexible Collodion USP, Salicylic Acid
Liniments are solutions of various substances in oil, alcoholic
solutions of soap or emulsions which are intended for external application,
e.g. Ben Gay.
Oleaginous Solutions are solutions of fat soluble vitamins (Vitamin
A, O, and E), or other fat soluble substances in vegetable oils (corn,
cottonseed, olive, peanut, and sesame seed oils) or mineral oil. Oleaginous
solutions may be formulated for oral, topical or parenteral administration.
The nonpolar solvents used in pharmacy are essentially hydrocarbons
or glyceryl esters. Peanut, sesame, corn, cottonseed, and mineral oil are
most frequently chosen as solvents or vehicles.