external use only. The patient should be told to see his physician if the inflammatory
condition does not improve and to avoid getting the prepared solution in contact with his
eyes. Usually one or two of the tablets are dissolved in a pint of water. The patient is
then to soak the affected area two or three times daily in the freshly prepared solution
for 15 minutes.
(2) Calamine lotion (calamine and zinc oxide lotion). This product is used
as an astringent and as a protectant (used to cover and protect epithelial surfaces).
Both these actions aid in reducing inflammation associated with insect bites, poison ivy,
and sunburn. The patient receiving this product should be told that the preparation is
for external use only and that he should shake the product well before using it.
(3) Phenolated and mentholated calamine lotion. Phenol and menthol have
been added to the product above because they produce an antipruritic effect.
a. Definition. A keratolytic is an agent that induces sloughing of cornified
epithelium (horny or hard layer of the skin).
b. General Considerations. Keratolytic drugs act to damage the cornifled layer
of skin that is then sloughed off to whatever depth the agent has acted. A keratoplastic
(mild keratolytic) effect is seen when the drug does not produce a rapid destruction and
sloughing, thereby softening the keratin and loosening the cornified epithelium.
c. Indications for the Use of Keratolytic Agents. Keratolytic agents are used
to remove warts and corns. They are also used in the treatment of severe acne.
d. Indications for the Use of Keratoplastic Agents. Keratoplastic agents are
used in the treatment of acne, eczema, psoriasis, and seborrheic dermatitis.
Specific Keratolytic Agents.
You will see chemicals (1) through (4) present in several manufactured
products. You might be called upon to compound or manufacture products
containing one or more of these substances. If you handle these
chemicals, remember that they are irritating to the skin. You should
wash your hands immediately after working with them.
(1) Coal tar (chemical name). This agent is used as a keratoplastic in the
treatment of eczema, psoriasis, and seborrheic dermatitis.
(2) Salicylic acid (chemical name). It is used as a keratolytic when present
in concentrations of from 5% to 20%. It is used as a kerato- plastic when present in
concentrations of from 1% to 2%.