Learning Objectives

• Definition of ointment and its classification with examples
• Ointment bases and their classification with merits and demerits
• Different methods of manufacture of ointments

Ointments (unguents) are soft semisolid preparations meant for external application to the skin or mucous membrane. They usually contain medicament that is dissolved, suspended or emulsified in an ointment base. They may contain suitable antimicrobial preservatives. Ointments have emollient and protective action on the skin. They are also used to deliver drugs into eye, nose, vagina, and rectum. Ointments intended for ophthalmic purposes are required to be sterile.

Characteristics of an Ideal Ointment

1. It should have high physicochemical stability.
2. It should be smooth and not gritty.
3. It should melt or soften at body temperature.
4. It should be easy to apply.
5. Base(s) should be nonirritant and should have no therapeutic action.
6. It should be thixotropic in nature.

Advantages of Ointments

1. Handling is comparatively easier than bulky liquid dosage forms.
2. Chemical stability is more than liquid dosage forms.
3. They promote direct application to the affected body part and avoids unnecessary exposure of other parts to the medication.
4. They are suitable for patients sensitive to parenteral and oral routes.
5. They prolong the contact time between the medicament and affected region.
6. Drugs with extensive first-pass metabolism by oral route can be formulated as topical dosage forms.

Disadvantages of Ointments

1. They are bulkier compared to solid dosage forms.
2. They have less stability than solid dosage forms.

Classification of Ointments

Ointments are classified on the basis of several factors:

1. According to their therapeutic properties with penetration of skin
2. According to their therapeutic uses