Pharmaceutics and drug delivery systems CHAPTER 10 Ointments Creams and Gels

Learning Objectives

Differentiate between various types of ointment bases based on their physical and chemical properties.
List criteria for selecting an ointment base to treat topical afflictions.
Describe methods to incorporate active ingredients into an ointment base.
Explain the differences between ointments, creams, and gels.
Compare and contrast ophthalmic ointment bases with topical ointment bases for skin application.
List advantages and disadvantages of administering drugs rectally and vaginally.
Discuss counseling points pharmacists should share with patients for each topical product application route.

Semisolid dosage forms intended for topical application, including to the skin, eyes, nasally, vaginally, or rectally.
Utilized for both local and systemic effects, with special considerations for pregnant or nursing patients to avoid transferring drugs to fetal circulation or breast milk.
Ointments deliver drugs into the skin (target organ), while transdermal products deliver drugs through the skin for systemic effects (not targeting the skin).

Ointments are semisolid preparations for external application to skin or mucous membranes.
Can be medicated or unmedicated: unmedicated provides physical protective effects (emollients, lubricants).
Ointment bases serve as vehicles for medicated ointments.

Also known as hydrocarbon bases (e.g., petrolatum).
Characteristics: emollient effect, protect moisture, occlusive dressing; stay on skin for long periods.
Difficult to wash off; small amounts of water may be incorporated with difficulty.

Types:
- Allow incorporation of aqueous solutions (e.g., hydrophilic petrolatum).
- Water-in-oil (W/O) emulsions (e.g., lanolin).
Good as emollients and do not wash off easily.

Greaseless, entirely water washable, limited incorporation of large volumes of liquids; mainly for solids.
Example: Polyethylene glycol (PEG) ointments.

Combination of components until uniform; may use mortar, pestle, or spatula on ointment slab.
Levigation may be necessary for powdered ingredients.

Mixture components are melted together, then cooled while stirring; can include water-immiscible components.

Semisolid preparations in O/W or W/O emulsions; designed for easy spreading and removal.
Preferred by patients for topical skin products.

Dispersions rendered jellylike via gelling agents like carbomers or cellulose derivatives.
Used in various routes including skin, eyes, and nasal application.

Pastes: stiffer, thicker than ointments, used for absorbency and application to the skin.
Plasters: provide prolonged contact, can be medicated or unmedicated.
Glycerogelatins: contain gelatin and glycerin, used for long-term application; melted before use.

Use of appropriate dosing instruments when applying topical products is essential for effective treatment.

Ointments, creams, and gels packaged in jars, tubes, or syringes depending on the intended use.

Educate patients on proper application techniques for efficacy and safety.
Discuss potential for sensitivity or allergic reactions.
- Example: advise against using a product if symptoms persist.
Emphasize importance of cleaning the affected area prior to application.