Incorporation of Drugs into Ointment Bases

An ointment slab (left) and large metal spatulas should be used for this process. Ointment slabs are either ground glass plates or porcelain and provide a hard, nonabsorbable surface for mixing.

Ointment pads (right) have the advantage that "clean-up" is quicker, but the ointment can soak into the parchment paper. Further, the paper can absorb liquids and may tear when using sticky or thick ointments. Large metal spatulas are used instead of smaller metal spatulas because they have the proper combination of flexibility and strength for adequate shearing and mixing. Black rubber or plastic spatulas are not used in ointment compounding.

If preparing a large quantity of ointment, a mixing device of some type might be used instead of the ointment slab and spatula. Two options are an ointment mill, and an "electric mortar and pestle." Ointment mills produce very smooth and elegant ointments. The electric mortar and pestle allows the formulation of the ointment and the dispensing of the formulation to be done in the same container. (Photos courtesy of Professional Compounding Centers of America, Inc., Houston, Texas)

Ointment Mill

Electric Mortar and Pestle