Semisolid : Ointment/Bases

Question 1

Oleaginous Bases

Answer 1

• Hydrophobic
• Has emollient effect
• Difficult to wash with water
• Greasy and stain clothing
• Mineral oil is levigating agent.
• Occlusive: prevent the escape of water
• Do not dry out or change on aging
• Retained on the skin for long periods

Question 2

Oleaginous Bases

Answer 2

1-Petrolatum USP ( Vaseline).

2-White Petrolatum USP ( White Vaseline).

3-Yellow Ointment USP (simple ointment).

4-White Ointment USP.

Question 3

ABSORPTION BASES

Answer 3

1- Anhydrous Absorption Bases - absorb water to become w/o emulsion

2- (Hydrous Absorption Bases) (w/o) - can absorb more water

Question 4

1- Anhydrous Absorption Bases

Answer 4

• Emollient
• Occlusive
• Anhydrous
• Absorbs water
• Not water washable
• Greasy and stain clothing

e. g. Hydrophilic Petrolatum
e. g. Anhydrous Lanolin ( Lanolin USP)

Question 5

2- (Hydrous Absorption Bases) (w/o)

Answer 5

1. Emollient
2. Occlusive
3. Contain water to start with
4. Absorb additional water
5. Greasy and stain clothing

• Examples:

1. Hydrous Lanolin
2. Cold cream(cleansing creams)

– Commercially Eucerin & Nivea cream

Question 6

WATER REMOVABLE BASES

Answer 6

• O/W emulsions
• Also called “Water-washable Bases” creams.
• External phase is water
• Easily water washable bases.
• Can be diluted with water or aqueous solutions.
• Non greasy
• Must be preserved
• Cosmetically elegant.
• Hydrophilic ointment is an example

Question 7

WATER SOLUBLE BASES

Answer 7

• Contain only water soluble components
• May include gelled aqueous solutions
• Water washable, lipid free, greaseless
• No oleaginous component
• for non-aqueous or solid substance incorporation.
• Non-occlusive and may dehydrate SC
• High drug solubility in the base may lead to poor bioavailability.
• Major component is PEG (polyethylene glycol)
• Example : PEG ointment NF

Question 8

Incorporation

Answer 8

• “mix together”. For insoluble drugs
• Utilize trituration, then levigation to form a paste
• Levigating Agents : mineral oil, glycerin or propylene glycol.

Question 9

Levigating Agents

Answer 9

• Mineral oil is the best choice for oleaginous bases.
• Water soluble or miscible levigating agents are: Water, glycerin, alcohol, or propylene glycol.
• Oil soluble levigating agent is Mineral oil.

Question 10

Fusion

Answer 10

• Melting, mixing , cooling , congealing.
• Heat sensitive and volatile substances are added last.
• Solutions and levigated solids may be added to the congealed base.
• In porcelain dish or beaker, industry: steel-jacketed kettles.

Question 11

Creams

Answer 11

• one or more medicinal agent dissolved or dispersed in either a w/o emulsion or an o/w emulsion or water washable bases.
• Topical, vaginal, rectal creams…
• Easier to spread and easier to remove than ointments
• Pharmaceutical creams are classified as waterremovable bases in the USP and are described under Ointments.

Question 12

Vanishing Cream: o/w emulsion

Answer 12

• containing large percentage of water and stearic acid or other oleaginous components
• upon application water evaporates leaving a thin residue film of the stearic acid or other oleaginous component.

Question 13

Cold Cream

Answer 13

• w/o emulsion
• Ex : Pond’s Cold cream ( make up removal )

Question 14

Gels

Answer 14

• a semisolid being either a suspension of small inorganic particles or a large organic molecule interpenetrated in a liquid medium.
• Rendered jelly like by the addition of a gelling agent.
• Not tacky
• Spread readily
• Easily removed from skin
• Most are clear patient compliance

Question 15

Gelling Agents

Answer 15

1. Cellulose derivatives such as methylcellulose, hydroxypropyl methylcellulose (HPMC),and other derivatives
2. Polysaccharides(natural) such as xanthan gum ,tragacanth, alginates, and carrageenan.
3. Acrylic polymers(synthetic) such as Carbomer that form gels at concentrations as low as 0.5%.
4. Colloidal dispersed solids such as silica and clays.

Question 16

Lotions

Answer 16

• Lotions are suspensions of solids in an aqueous medium.
• Intended to be applied to unbroken skin with no friction
• Prepared by triturating the ingredients to a smooth paste and then adding the remaining liquid phase with trituration.
• Larger scale use of High-speed mixers or colloid mills produce better dispersion.

Question 17

Pastes

Answer 17

• Prepared by fusion or incorporation.
• Contain a larger percentage of solid material than ointments (thicker and stiffer).
• Will not soften and flow after application.
• Should not be applied to hairy parts.
• Used to absorb serous secretions.

Question 18

Plasters

Answer 18

• Plasters are intended for external application
• Adhesive material made of rubber base or resin
• May be medicated ( 10-40% salicylic acid for corns)
• Or unmedicated for the mechanical protection or support.

Question 19

Liniments

Answer 19

• Liniments are of a similar viscosity to lotions (being significantly less viscous than an ointment or cream) but unlike a lotion a liniment is applied with friction, that is a liniment is always rubbed in.
• Liniments are typically sold to relieve pain and stiffness, such as from sore muscles or from arthritis.
• These liniments typically are formulated from alcohol, acetone, or similar quickly evaporating solvents, and contain counterirritant aromatic chemical compounds such as benzoin resin or capsaicin.

Question 20

Collodions

Answer 20

Collodions are liquid preparation containing pyroxylin, a partially nitrated cellulose, in a mixture of ethyl ether and ethanol.