Lab One- Ointment Bases

What are ointments?

Semisolid preparations designed for external application to the skin or mucous membranes

Name three characteristics of a good ointment base

They soften/melt at body temperature, should spread easily, and have no gritty texture

The effectiveness of drug penetration from an ointment depends on?

Amount of pressure and rubbing, the surface area covered, the condition of the skin, the type of base used, and the occlusive dressings

What are the three general purposes for using ointments?

1. Protecting injured areas from the environment to allow skin to heal

2. provide hydration and soothing to the skin

3. deliver medications to the skin for local or systemic effects

Ointment bases are differentiated based on?

Their physical composition

What are the five types of ointment bases?

Oleaginous, absorption, water-in-oil emulsion, oil-in-water emulsion, and water-soluble bases

Describe the composition of oleaginous bases

oleaginous compounds

Describe the composition of absorption bases

oleaginous base with water-in-oil surfactant

Describe the composition of water-in-oil emulsion bases

oleaginous, water (<45%), and water-in-oil surfactant (HLB <8)

Describe the composition of oil-in-water emulsion bases

oleaginous base, water (>45%), and oil-in-water surfactant (HLB >9)

Describe the composition of water miscible bases

polyethylene glycols

Give the water content of oleaginous bases

anhydrous

Give the water content of absorption bases

anhydrous

Give the water content of water-in-oil emulsion bases

hydrous

Give the water content of oil-in-water emulsion bases

hydrous

Give the water content of water miscible bases

anhydrous or hydrous

Give the affinity for water of oleaginous bases

hydrophobic

Give the affinity for water of absorption bases

hydrophilic

Give the affinity for water of water-in-oil emulsion bases

hydrophilic

Give the affinity for water of oil-in-water emulsion bases

hydrophilic

Give the affinity for water of water miscible bases

hydrophilic

Describe the spreadability of oleaginous bases

difficult

Describe the spreadability of absorption bases

difficult

Describe the spreadability of water-in-oil emulsion bases

moderate to easy

Describe the spreadability of oil-in-water emulsion bases

easy

Describe the spreadability of water msicible bases

moderate to easy

Describe the washability of oleaginous bases.

nonwashable

Describe the washability of absorption bases.

nonwashable

Describe the washability of water-in-oil emulsion bases.

non or poorly washable

Describe the washability of oil-in-water emulsion bases.

washable

Describe the washability of water msicible bases.

washable

Describe the drug incorporation potential of oleaginous bases

Can incorporate solids or oils

Describe the drug incorporation potential of absorption bases

Can incorporate solids, oils, and aqueous solutions

Describe the drug incorporation potential of water-in-oil emulsion bases

Can incorporate solids, oils, and aqueous solutions

Describe the drug incorporation potential of oil-in-water emulsion bases

Can incorporate solids and aqueous solutions

Describe the drug incorporation potential of water miscible bases

Can incorporate solids and aqueous solutions

Are oleaginous bases occlusive? (create a protective layer on the skin to prevent water loss)

Yes

Are absorption bases occlusive? (create a protective layer on the skin to prevent water loss)

Yes

Are water-in-oil emulsion bases occlusive? (create a protective layer on the skin to prevent water loss)

Sometimes

Are oil-in-water emulsion bases occlusive? (create a protective layer on the skin to prevent water loss)

No

Are water-miscible bases occlusive? (create a protective layer on the skin to prevent water loss)

No

Describe the uses of oleaginous bases

Protectants, emollients, vehicles of hydrolyzable drugs

Describe the uses of absorption bases

Protectants, emollients, vehicles for aqueous solutions, solids, and non-hydrolyzable drugs

Describe the uses of water-in-oil emulsion bases

Emollients, cleansing creams, vehicles for solids, liquid, and non-hydrolyzable drugs

Describe the uses of oil-in-water emulsion bases

Emollients, vehicles for solid, liquids, and non-hydrolyzable drugs

Describe the uses of water-miscible bases

Drug vehicles

Give some examples of oleaginous bases

White petrolatum and white ointment

Give some examples of absorption bases

Hydrophilic petrolatum, anhydrous lanolin, aquabase Aquaphor, and polysorb

Give some examples of water-in-oil emulsion bases

Cold cream type, hydrous lanolin, rose water ointment, hydrocream, eucerin, and nivea

Give some examples of oil-in-water emulsion bases

Hydrophilic ointment dermabase, velvachol, and unibase

Give some examples of water-miscible bases

PEG ointment and polybase

Always add ___% excess of all ingredients when compounding ointment bases

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