CLASSES OF AQUEOUS PREPARATION
Section I. SOLUTIONS
a. Importance of Solutions. Many drugs are supplied in solution form.
Consider intravenous (IV) solutions. Many IV solutions are administered to patients
who are in military or civilian hospitals across the United States. Further, think of the
number of prescriptions written every fall and winter for decongestant solutions.
Although most outpatient pharmacy services dispense more tablets and capsules than
solutions, it is easy to see that solutions are still important in the field of pharmacy.
b. Definition of Solution. A solution is a homogeneous mixture of two or more
substances. Typically, a drug is placed in water.
c. Parts of a Solution. A solution consists of two parts:
(1) Solute. The solute is usually the active ingredient. It is the substance
that is dissolved in the second part of the solution, the solvent. The solute is usually
present in a lower proportion than is the solvent.
(2) Solvent. The solvent serves as the vehicle for the solute. That is, the
solute is dissolved in the solvent.
USES OF SOLUTIONS
Solutions may be used either internally or externally. Intravenous solutions are
intended for internal use. Mouthwashes are intended for external use. They are not
intended to be swallowed. Solutions have many pharmaceutical uses. Immediately
following are some uses of solutions.
a. Collyria-use in the eye.
b. Collutoria--for use as mouthwashes.
c. Collunaria--for use in the nose or nasopharynx.
d. Douches--for instillation into one of the body cavities.
e. Enemas--for instillation into the rectum.