IV. Semisolids - Ointments

Ointment

Semisolid preparations intended for external application to the skin or mucus membranes

• Oleaginous
• Absorption
• Water Removable
• Water Soluble

4 Ointment Bases

Oleaginous Base

Ointment Base characteristic:
• Greasy
• Emollient & Occlusive

Absorption Base

Ointment Base characteristic:
• Greasy
• Less Emollient & Occlusive
• W/O

Water Removable

Ointment Base characteristic:
• Non Greasy
• O/W

Water Soluble

Ointment Base characteristic:
• Non Greasy
• For incorporation of solid substances

• Yellow Petrolatum (Petroleum, Vaseline)
• White Petrolatum
• Yellow Wax (Beeswax)
• White Wax
• Yellow Ointment (Simple Ointment)
• White Ointment

6 Oleaginous Bases

Yellow Petrolatum (Petroleum, Vaseline)

Mix of HC Petroleum

White Petrolatum

Decolorized Petrolatum

Yellow Wax (Beeswax)

From bee apis mellifera

White Wax

Decolorized wax

Yellow ointment (SImple ointment)

Yellow petrolatum + Yellow wax

White ointment

White petrolatum + White wax

• Hydrophilic Petrolatum (Aquaphor)
• Lanolin

2 Absorption Bases

• Cholesterol
• Stearyl alcohol

Hydrophilic Petrolatum (Aquaphor) emulsifying agents

Lanolin

From sheep wool ovies aries

Hydrophilic ointment

Water Removable example

PEG Ointment

Water Soluble example

<600 - Clear
600-1000 - Semisolid
>1000 - White

PEG Ointment MW

Cream

Semisolid preparations containing one or more medicinal agents dissolved or dispersed in either a w/o or o/w emulsion

• Vanishing cream
• Cold cream

Cream examples

Vanishing cream

o/w cream

Cold cream

w/o

Gels

Semisolid systems consisting of dispersions of small or large molecules in an aqueous liquid vehicle rendered jelly-like by a gelling agent

• Imbibition
• Swelling
• Syneresis
• Xerogel
• Bleeding
• Thixotropy
• Rheopexy

7 Gel Phenomena

Imbibition

Take up liquid WITHOUT increase in volume

Swelling

Take up liquid WITH increase in volume

Syneresis

Gel shrinks with loss of liquid

Xerogel

Liquid is removed & only framework remains (result of Syneresis)

Bleeding

Liberation of oil/water

Thixotropy

Reversible gel-sol formation

Rheopexy

Irreversible sol-gel formation

Pastes

contains larger proportion of solid materials than ointments

Plasters

Solid or semi-solid moist masses spread on an adhesive backing or paper, fabric, moleskin, or plastic

Poultices

• aka cataplasms
• consists of plant materials
• applied hot on a cloth

Pledges

cotton or cotton wool to apply disinfectant

Glycerogelatin

• applied with a fine brush
Components:
• 40% Glycerin
• 35% Water
• 15% Gelatin
• 10% API

40%

Glycerogelatin Components:
Glycerin %

35%

Glycerogelatin Components:
Water %

15%

Glycerogelatin Components:
Gelatin %

10%

Glycerogelatin Components:
API %