OINTMENTS, CREAMS, AND GELS

Ointments, Creams, and Gels

semisolid dosage forms intended for topical application (local or systemic effects)

topical dermatological product

delivers drug into the skin in treating dermal disorders, with the skin as the target organ

transdermal product

delivers drugs through the skin (percutaneous absorption) to the general circulation for systemic effects, with the skin not being the target organ

ointments

semisolid preparations intended for external application to the skin or mucous membranes that may be medicated or not

unmedicated ointments

used as protectants, emollients, or lubricant

ointment bases

may be used for their physical effects or as vehicles for medicated ointments (oleaginous, absorption bases, water-removable, water-soluble)

Oleaginous bases

• also termed hydrocarbon bases

• have an emollient effect, protect against the escape of moisture, are effective as occlusive dressings, can remain on the skin for long periods without drying out, difficult to wash off

• water and aqueous preparations may be incorporated, but only in small amounts

Petrolatum, USP

EXAMPLE OF OLEAGINOUS BASES:

• purified mixture of semisolid hydrocarbons obtained from petroleum

• unctuous mass, varying in color from yellowish to light amber

• melts at 38°C to 60°C

• also known as yellow petrolatum and petroleum jelly

• commercial product - Vaseline

White Petrolatum, USP

EXAMPLE OF OLEAGINOUS BASES:

• purified mixture of semisolid hydrocarbons from petroleum that has been wholly or nearly decolorized

• lighter color, considered more esthetically pleasing

• also known as white petroleum jelly

• commercial product - White Vaseline

Yellow Ointment, USP

EXAMPLES OF OLEAGINOUS BASES:

• yellow wax - purified wax obtained from the honeycomb of the bee Apis mellifera

• also called simple ointment

• has a slightly greater viscosity than plain petrolatum

White Ointment, USP

• differs from yellow ointment by substitution of white wax (bleached and purified yellow wax) and white petrolatum in the formula

Absorption Bases

• may be used as emollients, although they do not provide the degree of occlusion afforded by the oleaginous bases

• not easily removed from the skin with water washing

• useful as pharmaceutical adjuncts to incorporate small volumes of aqueous solutions into hydrocarbon bases

• 2 types:

  • those that permit the incorporation of aqueous solutions resulting in the formation of W/O emulsions (e.g., hydrophilic petrolatum)

  • those that are W/O emulsions (emulsion bases) that permit the incorporation of additional quantities of aqueous solutions (e.g., lanolin)

Hydrophilic Petrolatum, USP

EXAMPLES OF ABSORPTION BASES:

• prepared by melting the stearyl alcohol and white wax on a steam bath, adding the cholesterol with stirring until dissolved, adding the white petrolatum, and allowing the mixture to cool while stirring until congealed

Lanolin, USP

EXAMPLES OF ABSORPTION BASES:

• anhydrous lanolin

• obtained from the wool of sheep (Ovis aries) purified waxlike substance that has been cleaned, deodorized, and decolorized

• contains not more than 0.25% water

Modified Lanolin, USP

EXAMPLES OF ABSORPTION BASES:

• Lanolin processed to reduce the contents of free lanolin alcohols and any detergent and pesticide residues

Water-Removable Bases

• oil-in-water emulsions commonly called creams

• water-washable bases - easily washed from skin

• can absorb serous discharges

• e.g. Hydrophilic Ointment, USP

Water-Soluble Bases

• do not contain oleaginous components

• greaseless - completely water washable

• large amounts of aqueous solutions are not effectively incorporated into these bases

• e.g. Polyethylene Glycol Ointment, NF

Incorporation

PREPARATION OF OINTMENTS:

• components are mixed until a uniform preparation is attained

• mixing using mortar and pestle, spatula, ointment mill, unguator

Incorporation of Solids

• using stainless steel spatula; hard rubber or silicone spatulas (if components react with metal)

• prepared by thoroughly rubbing and working the components together on the hard surface until the product is smooth and uniform

geometric dilution, levigation, pulverization by intervention

incorporation of solid techniques

Incorporation of Liquids

• consideration on the ointment base's capacity to accept the volume required

• alcoholic solutions of small volume may be added easily to oleaginous vehicles or emulsion bases

ointment or roller mills

to produce ointments uniform in composition and smooth in texture

Fusion

• all or some of the components of an ointment are combined by being melted together and cooled with constant stirring until congealed

• heat-labile substances and any volatile components are added last

• may be conducted in a porcelain dish, glass beaker, steam-jacketed kettles

Microbial Content

COMPENDIAL REQUIREMENTS FOR OINTMENTS:

• topical applications are not required to be sterile

• preparations prone to microbial growth must contain antimicrobial preservatives

• microbial limits (e.g. Betamethasone Valerate Ointment, USP must meet the requirements of the tests for absence of Staphylococcus aureus and Pseudomonas aeruginosa)

Minimum Fill

COMPENDIAL REQUIREMENTS FOR OINTMENTS:

• determination of the net weight or volume of the contents of filled containers

Packaging, Storing, and Labeling

COMPENDIAL REQUIREMENTS FOR OINTMENTS:

• packaged either in large-mouth ointment jars or in metal or plastic tubes

• stored in well-closed containers and in a cool place

• packaged in opaque or light-resistant containers (for light-sensitive preparations

Creams

• semisolid preparations containing one or more medicinal agents dissolved or dispersed in either a W/O or O/W emulsion or in another type of water-washable base

• applications: topical skin products and in products used on mucous membranes (rectally and vaginally)

• generally described as either non-washable or washable

cold cream

w/o cream

vanishing cream

o/w cream

oils

Preparation of Creams:

1. may be formulated from a variety of ______, both mineral and vegetable, and from fatty alcohols, fatty acids, and fatty esters

2. __________________ are melted at the time of preparation

3. _______________: nonionic surfactants, detergents, and soaps

4. separating the formula components into 2 portions: _________________

5. _________ can be added to the phase in which it is soluble

6. require the addition of a _______________

1 = ?

solid excipients

Preparation of Creams:

1. may be formulated from a variety of ______, both mineral and vegetable, and from fatty alcohols, fatty acids, and fatty esters

2. __________________ are melted at the time of preparation

3. _______________: nonionic surfactants, detergents, and soaps

4. separating the formula components into 2 portions: _________________

5. _________ can be added to the phase in which it is soluble

6. require the addition of a _______________

2 = ?

emulsifying agents

Preparation of Creams:

1. may be formulated from a variety of ______, both mineral and vegetable, and from fatty alcohols, fatty acids, and fatty esters

2. __________________ are melted at the time of preparation

3. _______________: nonionic surfactants, detergents, and soaps

4. separating the formula components into 2 portions: _________________

5. _________ can be added to the phase in which it is soluble

6. require the addition of a _______________

3 = ?

lipid and aqueous

Preparation of Creams:

1. may be formulated from a variety of ______, both mineral and vegetable, and from fatty alcohols, fatty acids, and fatty esters

2. __________________ are melted at the time of preparation

3. _______________: nonionic surfactants, detergents, and soaps

4. separating the formula components into 2 portions: _________________

5. _________ can be added to the phase in which it is soluble

6. require the addition of a _______________

4 = ?

APIs

Preparation of Creams:

1. may be formulated from a variety of ______, both mineral and vegetable, and from fatty alcohols, fatty acids, and fatty esters

2. __________________ are melted at the time of preparation

3. _______________: nonionic surfactants, detergents, and soaps

4. separating the formula components into 2 portions: _________________

5. _________ can be added to the phase in which it is soluble

6. require the addition of a _______________

5 = ?

preservative

Preparation of Creams:

1. may be formulated from a variety of ______, both mineral and vegetable, and from fatty alcohols, fatty acids, and fatty esters

2. __________________ are melted at the time of preparation

3. _______________: nonionic surfactants, detergents, and soaps

4. separating the formula components into 2 portions: _________________

5. _________ can be added to the phase in which it is soluble

6. require the addition of a _______________

6 = ?

Gels

• sometimes called jellies

• semisolid systems consisting of dispersions of small or large molecules in an aqueous liquid vehicle rendered jellylike by the addition of a gelling agent

carbomer 934

gelling agents: synthetic macromolecules

carboxymethylcellulose or hydroxypropyl methylcellulose

gelling agents: cellulose derivatives

tragacanth

gelling agents: natural gums

Single-phase gels

macromolecules are uniformly distributed throughout a liquid with no apparent boundaries between the dispersed macromolecules and the liquid

Two-phase System

consisting of floccules of small distinct particles often referred to as a magma

Milk of Magnesia (Magnesia magma)

• ex of a two phase system

• consists of a gelatinous precipitate of magnesium hydroxide

thixotrope

Gels may thicken on standing (___________) and must be shaken before use to liquefy the gel and enable pouring

dispersing

Preparation of Gels:

1. ________ the molecule in the continuous phase (e.g., by heating starch)

2. ________ the dispersed molecules by changing the pH (as for carbomers)

3. __________ the continuous phase (as for jellies formed with sucrose)

1 = ?

cross-linking

Preparation of Gels:

1. ________ the molecule in the continuous phase (e.g., by heating starch)

2. ________ the dispersed molecules by changing the pH (as for carbomers)

3. __________ the continuous phase (as for jellies formed with sucrose)

2 = ?

reducing

Preparation of Gels:

1. ________ the molecule in the continuous phase (e.g., by heating starch)

2. ________ the dispersed molecules by changing the pH (as for carbomers)

3. __________ the continuous phase (as for jellies formed with sucrose)

3 = ?

tight containers

Packaging and Storage:

1. stored in __________________ to prevent water loss

2. avoid __________________

1 = ?

freezing

Packaging and Storage:

1. stored in __________________ to prevent water loss

2. avoid __________________

2 = ?

Pastes

• semisolid preparations intended for application to the skin

• contain a larger proportion of solid material (such as 25%) than ointments and therefore are stiffer

• remain in place after application and are effectively employed to absorb serous secretions

• not suited for application to hairy parts of the body

Plasters

• solid or semisolid adhesive masses spread on a backing of paper, fabric, moleskin, or plastic

• adhesive material is a rubber base or a synthetic resin

• applied to the skin to provide prolonged contact at the site

• may be unmedicated or medicated

Glycerogelatins

• plastic masses containing gelatin (15%), glycerin (40%), water (35%), and an added medicinal substance (10%)

• applied to the skin for the long term

• melted before application, cooled to slightly above body temperature, and applied to the affected area with a fine brush

• hardens, covered with a bandage, allowed to remain in place for weeks

Filling Ointment Jars

PACKAGING SEMISOLID PREPARATIONS:

• made of clear or opaque glass or plastic filled by spatula, pouring, or pressure fillers

Filling Ointment Tubes

PACKAGING SEMISOLID PREPARATIONS:

• made of aluminum or plastic

• light in weight, relatively inexpensive, convenient for use, compatible with most formulative components, provide greater protection against external contamination and environmental conditions than jars

• filled from the open back end of the tube through manual filling or small-scale automatic filling machine

Aluminum Tubes

coated with an epoxy resin, vinyl, or lacquer

low density polyethylene

plastic tubes that are soft and resilient, provides a good moisture barrier

High Density Polyethylene

plastic tubes that are superior moisture barrier but is less resilient

polypropylene

plastic tubes that have a high level of heat resistance

polyethylene terephthalate

plastic tubes that has a transparency and high degree of product chemical compatibility

laminates

plastic tubes that have excellent moisture barrier, high durability, product compatibility; can be plastic, foil, or paper

plunger

FILLING SYRINGES:

• by drawing the semisolid into the barrel using the a.__________ or by removing the plunger and filling through the _______ of the syringe

a = ?

back end

FILLING SYRINGES:

• by drawing the semisolid into the barrel using the a.__________ or by removing the plunger and filling through the _______ of the syringe

b = ?