CHAPTER 10: OINTMENTS, CREAMS, AND GELS

SECTION IV. SEMISOLID DOSAGE FORMS & TRANSDERMAL SYSTEMS

Intended for topical application

SEMI-SOLID DOSAGE FORMS

Target Sites SEMI-SOLID DOSAGE FORMS: (5)

to be applied in the skin, surface of the eye, used nasally, vaginally, and rectally

Semi-solid preparations intended for external application to the skin or mucous

OINTMENTS

Types of ointments: (2)

1. Medicated ointments

2. Unmedicated ointments

Types of ointments:

_used for the effects of the therapeutic agents or active drug they contain.

Medicated ointments

Types of ointments:

_used for their physical effect. Does not contain therapeutic agent or active drug.

Unmedicated ointments

Unmedicated ointments are used as: (4)

Used as a protectant, lubricant, emollient, or a vehicle for medicated ointment

Ointment bases: (ointments are not produced without these) (4)

1. Oleaginous bases/Hydrocarbon(hydrophobic)/Fatty base

2. Absorption bases

3. Water-removable bases/Water-washable bases

4. Water-soluble bases/Greaseless

T/F: Petrolatum: petroleum jelly are (unmedicated ointment)

True

Oleaginous bases/Hydrocarbon(hydrophobic)/Fatty base (2)

1. Petrolatum

   • Yellow Petrolatum, Yellow Jelly

2. Yellow Ointment

   • White ointment

Absorption bases (2)

1. Hydrophilic petrolatum

2. Lanolin

Water-removable bases/Water-washable bases (1)

Hydrophilic ointment

Water-soluble bases/Greaseless (1)

PEG ointment

Characteristics:

a. They have an emollient effect

b. Protect against the escape of moisture/hold moisture

c. Effective as occlusive dressings (can remain on the skin for a long period of time without drying out)

d. Immiscible with water (hydrocarbon = hydrophobic)

Difficulty: Difficult to wash off

OLEAGINOUS BASES (Hydrocarbon Bases) (Fatty Bases)

• Purified mixture of semisolid hydrocarbons obtained from petroleum.

  Characteristics:

  • Color: Yellowish to light amber

  • Melting point: 38°C to 60°C

  Commercial product: Vaseline®

  :can be used alone or in combination with other agent or ointment base

PETROLATUM, USP (Yellow petrolatum / Petroleum Jelly

PETROLATUM, USP (Yellow petrolatum / Petroleum Jelly)

Characteristics:

• Color: __

• Melting point: __

• Color: Yellowish to light amber

• Melting point: 38°C to 60°C

__can be used alone or in combination with other agent or ointment base

PETROLATUM, USP (Yellow petrolatum / Petroleum Jelly)

Purified mixture of semisolid hydrocarbon from petroleum that has been wholly or nearly decolorized.

Characteristics:

• Lighter color thus considered more aesthetically pleasing

• Commercial product: White Vaseline®

WHITE PETROLATUM, USP (White Petroleum Jelly)

WHITE PETROLATUM, USP (White Petroleum Jelly)

Characteristics:

• __ thus considered more aesthetically pleasing

Lighter color

__is a preparation containing yellow wax + petrolatum (any petrolatum, can be white or yellow)

YELLOW OINTMENT, USP (Simple Ointment)

YELLOW OINTMENT, USP (Simple Ointment) is a preparation containing __ (any petrolatum, can be white or yellow)

yellow wax + petrolatum

Is a preparation containing yellow wax + petrolatum (any petrolatum, can be white or yellow)

• Yellow wax – purified wax obtained from the honeycomb of the bee (apis mellifera)

  Characteristic:

  • Slighty greater viscosity than plain petrolatum

    Formulation:

    • Yellow wax 50g

    • Petrolatum 950g

YELLOW OINTMENT, USP (Simple Ointment)

__purified wax obtained from the honeycomb of the bee (apis mellifera)

Yellow wax

Slighty greater viscosity than plain petrolatum

YELLOW OINTMENT, USP (Simple Ointment)

YELLOW OINTMENT, USP (Simple Ointment)

Formulation: with their quantity

• Yellow wax 50g

• Petrolatum 950g

__this ointment differs from yellow ointment by substitution of white wax and white petrolatum in the formula.

WHITE OINTMENT, USP

_the bleached and purified form of the yellow wax

White wax

__wholly or nearly decolorized form of the yellow petrolatum

White petrolatum

__similar with yellow ointment but this used the bleached form.

WHITE OINTMENT, USP

Types:

a. Permit the incorporation of aqueous solution resulting to an water-in-oil emulsion (Hydrophilic petrolatum)

b. Those that are water-in-oil emulsions/emulsion bases that permit the incorporation of additional quantities of aqueous solutions (Lanolin)

ABSORPTION BASE:

Characteristics:

• Emollient effect

• Oleaginous external phase

ABSORPTION BASE

permit the incorporation of aqueous solution resulting to an water-in-oil emulsion

hydrophilic petrolatum

__ those that are water-in-oil emulsions/emulsion bases that permit the incorporation of additional quantities of aqueous solutions

lanolin

compared to oleaginous base, it has lesser degree of occlusion.

ABSORPTION BASE

__since it has the oleaginous external phase, this ointment is also not easily removed on the skin with water, but oleaginous bases are still harder to remove.

ABSORPTION BASE

Both have difficulty in removing with water.

Oleaginous base and Absorption base

_useful as a pharmaceutical adjunct to incorporate small volume of aqueous solution into hydrocarbon bases

ABSORPTION BASE

__ – hard to incorporate aqueous solution and to be able to incorporate it, __ must be added

Oleaginous bases (hydrophobic) – hard to incorporate aqueous solution and to be able to incorporate it, absorption bases must be added

__→ __ → __ = more occlusive effect

Active drug (aqueous solution) → absorption base → oleaginous bases = more occlusive effect

Is a preparation containing:

Cholesterol + Stearyl alcohol + white wax + white petrolatum

HYROPHILIC PETROLATUM, USP

HYROPHILIC PETROLATUM, USP

Is a preparation containing: __ + __ + __ + __

HYROPHILIC PETROLATUM, USP

Is a preparation containing: Cholesterol + Stearyl alcohol + white wax + white petrolatum

Formulation of HYROPHILIC PETROLATUM, USP:

Formulation:

• Cholesterol __

• Stearyl alcohol __

• White wax __

• White petrolatum __

Formulation:

• Cholesterol 30g

• Stearyl alcohol 30g

• White wax 80g

• White petrolatum 860g

Commercial product of HYROPHILIC PETROLATUM, USP:

Aquaphor® (variation of hydrophilic petrolatum)

Advantage: It can absorb water 3x than the original hydrophilic petrolatum

HYROPHILIC PETROLATUM, USP

A purified, wax-like substance that has been cleaned, deodorized and decolorized from the wool of sheep (Ovis aries)

LANOLIN, USP (Anhydrous Lanolin)

LANOLIN, USP (Anhydrous Lanolin) is a purified, wax-like substance that has been cleaned, deodorized and decolorized from the __

wool of sheep (Ovis aries)

for greater water content, __ can be used because it contains 25% content of water

for greater water content, Hydrous form of Lanolin can be used because it contains 25% content of water

A.K.A: water-washable base

WATER-REMOVABLE BASE

Characteristics:

a. Oil-in-water emulsion type (water is the external)

b. Aqueous external phase

c. Can absorb serous discharge

WATER-REMOVABLE BASE (Water-washable base)

Example: Hydrophilic Ointment, USP

WATER-REMOVABLE BASE (Water-washable base)

HYDROPHILIC OINTMENT, USP preparation containing: (6)

1. Methylparaben and Propylparaben

   • antimicrobial preservatives

   • powder form

2. Sodium Lauryl Sulfate

   • surfactant

   • emulsifying agent

   • solution form

3. Propylene glycol

   • liquid form

4. Stearyl alcohol

5. White petrolatum

6. Purified water

Prepared by melting/fusion method

• Stearyl alcohol and white petrolatum is melted 75°C, then the rest is dissolve in water by stirring.

HYDROPHILIC OINTMENT, USP

HYDROPHILIC OINTMENT, USP is pepared by __

• __ and __ is melted __, then the rest is dissolve in water by stirring.

melting/fusion method

• Stearyl alcohol and white petrolatum is melted 75°C, then the rest is dissolve in water by stirring.

Characteristics:

• Do not contain oleaginous components

• Completely water-washable because they soften greatly with the addition of water

Used: Incorporation of solid substances

Example base:

• Polyethylene Glycol (PEG) Ointment

WATER-SOLUBLE BASES (Greaseless)

Characteristics:

• Do not contain oleaginous components

• Completely water-washable because they soften greatly with the addition of water

WATER-SOLUBLE BASES (Greaseless)

Used: Incorporation of solid substances

WATER-SOLUBLE BASES (Greaseless)

__is a polymer of ethylene oxide and water represented by formula H(OCH2CH2)nOH

Characteristics:

• MW below 600 (clear, colorless liquids)

• MW above 1000 (wax-like white materials)

• MW in between 600-1000 (semisolids)

POLYETHYLENE GLYCOL OINTMENT, NF

POLYETHYLENE GLYCOL OINTMENT, NF Characteristics: (3)

• MW below 600 (clear, colorless liquids)

• MW above 1000 (wax-like white materials)

• MW in between 600-1000 (semisolids)

T/F: the greater the MW of the polyethylene glycol, the clear the product

False; the greater the MW of the polyethylene glycol, the greater the viscosity of the product

FACTORS IN SELECTING THE APPROPRIATE OINTMENT BASE

1. Desired release rate of the drug substances from the ointment base

• Example: If you want a longer release rate of the drug from the ointment, use hydrocarbons.

2. Desirability of topical or percutaneous drug absorption

> Characteristics of the skin must be considered. Use a base with the same characteristics of the skin which is more of the water type.

• Example: Suitable for percutanous absorption is absorption bases

3. Desirability of occlusion of moisture from the skin

• Example: Oleaginous bases – petrolatum

4. Stability of the drug in the ointment base

5. Effect of the drug on the consistency or the other features of the ointment base

> The end product will depend on the ointment base used.

• Example: Using of liquid = absorption bases before adding to other ointment bases

> Oleaginous + absorption = partner since the absorption bases can counteract the problem of oleaginous bases

6. Desire for a base easily removed by washing with water.

• Example: Water-removable and water-soluble bases

7. Characteristics of the surface to which it is applied

> take into consideration on what part of the body it is applied

• Example: Hairy parts of the body = no to viscous type of ointments since it is painful and will block the pores.

…

METHODS IN PREPARING OINTMENTS (2)

1. Incorporation

2. Fusion

• Components are mixed until uniform preparation is attained.

• Uses spatulation or levigation process

• Powder type

Equipment:

1. Mortar & Pestle (levigation process)

2. Ointment slab & spatula (spatulation)

3. Ointment mill, Electronic mortar and pestle, unguator (intermediate large scale of production)

• Incorporation of solids: spatulation or levigation

• Incorporation of liquid: directly add the liquid to the ointment base then mix until semi-solid

• Incorporation of gummy-like materials: Pulverization by intervention then followed by spatulation or levigation

INCORPORATION

Components are mixed until uniform preparation is attained.

INCORPORATION

• Uses spatulation or levigation process

• Powder type

INCORPORATION

INCORPORATION equipment: (3)

1. Mortar and Pestle (levigation process)

2. Ointment slab and spatula (spatulation process)

3. Ointment mill, Electronic mortar and pestle, unguator (intermediate large scale of production)

Incorporation of solids: __

Incorporation of liquid: __

Incorporation of gummy-like materials: __

Incorporation of solids: spatulation or levigation

Incorporation of liquid: directly add the liquid to the ointment base then mix until semi-solid

Incorporation of gummy-like materials: Pulverization by intervention then followed by spatulation or levigation

• Components are combined by being melted together and cooled with constant stirring until congealed.

• Uses heat

• Wax type or solid type

• Intended for materials which do not lend themselves well to mixture by incorporation

• Not suitable for heat-labile substances

• Heat-labile substances (wax type) and components are added last when temperature is low enough not to cause decomposition or volatilization of the components.

> In choosing the methods in preparing ointments, it primarily depends on the nature of the ingredients.

FUSION

Common materials for fusion process: (4)

If a formulation contains beeswax, paraffin, stearyl alcohol, high MW PEGS (polyethylene glycols)

COMPEDIAL REQUIREMENTS FOR OINTMENTS

Ointments and other semisolid dosage forms must meet USP tests for:

• Microbial content

• Minimum fill o Packaging, storage and labelling

• Sterility and Metal particles (Opthalmic ointment)

MICROBIAL CONTENT

Antimicrobial preservatives: (5)

• Methylparaben & propylparaben (MP – antifungal PP – antibacterial = synergistic antimicrobial)

• Phenols

• Benzoic acid

• Sorbic acid

• quaternary ammonium salts

MICROBIAL CONTENT

Preparations must meet the tests for absences of: For topical

• Staphylococcus aureus

• Pseudomonas aeruginosa

MICROBIAL CONTENT

Those intended for rectal, urethral, or vaginal use should be tested for:

• Yeasts (candida albicans)

• Molds

MINIMUM CONTENT

• Determination of the net weight or volume of the contents of filled containers to ensure proper contents compared with labelled amount.

• No to false claims

.

PACKAGING, STORAGE, AND LABELING

• Packaging: __ (unmedicated ointments) or in __ or __ (medicated ointments)

• Storage condition: __ to protect against contamination and in a cool place to protect against product separation in heat.

• Labeling: Ointments and creams should include the __.

• Packaging: Large-mouth ointment jars (unmedicated ointments) or in metal or plastic tubes (medicated ointments)

• Storage condition: Well-closed containers to protect against contamination and in a cool place to protect against product separation in heat.

• Labeling: Ointments and creams should include the type of base used.

• Semisolid preparations containing one or more medicinal agents dissolved or dispersed in either a water-in-oil emulsion or an oil-in-water emulsion or in another type of water-washable base.

• Primary application for topical skin products, and in products used rectally or vaginally

CREAMS

Types of creams:

1. Vanishing cream (oil-in-water emulsion)

2. Cold cream (water-in-oil emulsion)

Contains large percentage of water, and less percentage of stearic acid or other oleaginous components.

Vanishing cream (oil-in-water emulsion)

Contains large percentage of oil or oleaginous components than water. ▪ Leaves a heavy or oily feeling on the skin

Cold cream (water-in-oil emulsion)

T/F: Creams have more advantages than ointments. Patients and physicians prefer creams than ointments.

True

Advantages of Creams:

• More preferred than ointment

• Ease of spreadability and remove (even cold creams because this uses an oil that is still can be easily removed)

• Less viscid and lighter than ointment

• Greater aesthetic appeal for their non-greasy character

• Ability to vanish into the skin upon rubbing

• Absorbs serous discharge from skin lesions (compared to other ointment bases except water-washable and water-removable bases)

.

For spot treatments =__

For large surface area of the skin = __

For spot treatments = ointments

For large surface area of the skin = creams