university of sulaimani school of pharmacy dept. of ... · university of sulaimani school of...

University of Sulaimani School of Pharmacy

Dept. of PharmaceuticsThird level - Second semester

5/14/2017 Pharmaceutical Compounding, Dr. rer. nat. Rebaz Ali 1


Outlines

• Introduction

• Ointments bases

• Creams

• Pastes


Terminology and skin structure

• Topical drug delivery is the application of a formulation to the skin to treat a local

disorder, like locally acting steroids.

• Transdermal drug delivery is the application of a formulation to the skin to deliver a

drug to the systemic circulation, for example, estradiol patches.

• Permeant is the chemical species that is moving through or into the tissue. This will

be the drug, but may also be other ingredients within the formulation.

• Permeation is movement of drug through the membrane.

• Penetration is entry into the tissue. Penetration does not necessarily require the

molecules to pass out of the tissue.


Terminology and skin structure cont.

• Skin structure


Outlines

• Introduction

• Ointments bases

• Selection of the bases

• Method of preparation

• Creams

• Pastes


Ointments

• Ointments are semisolid preparations intended for external application to the skin or

mucous membranes.

• Ointments may be medicated or not.

• They may be applied to the skin, or the mucous membrane, like vagina/vulva,

rectum, nose or eye.

• Unmedicated ointments are used for the physical effects they provide as protectants,

emollients, or lubricants.

• The formulation of ointments and pastes

involves the dispersal or dissolution of the

selected therapeutic agent into an ointment

base


Ointment bases

Oleaginous

Petrolatum

Absorption

Permit addition of water

W/O emulsion

Water removable

Hydrophilic ointment

Water-soluble

PEG oint.


Oleaginous bases

• They are also called hydrocarbon bases.

• They have an emollient effect

• They can remain on the skin for long periods without drying out.

• Incorporation of water is very difficult.

• When powdered substances are to be incorporated into hydrocarbon bases, liquid

petrolatum (mineral oil) may be used as the levigating agent.

• Petrolatum, USP, is a purified mixture of semisolid hydrocarbons

obtained from petroleum.

• It is also known as yellow petrolatum and petroleum jelly. A

commercial product is Vaseline


Oleaginous bases cont.

• White Petrolatum, USP, is a purified mixture of semisolid hydrocarbons from

petroleum that has been wholly or nearly decolorized.

• It is considered more esthetically pleasing by some pharmacists and patients.

• White petrolatum is also known as white petroleum jelly. A commercial product is

White Vaseline


Oleaginous bases cont.

• Yellow Ointment USP: (yellow wax: 50 g and petrolatum: 950 g) Yellow wax is the

purified wax obtained from they honeycomb.

• Also called simple ointment

• It has a slightly greater viscosity than plain petrolatum.

• White Ointment, USP.

• White wax (bleached and purified yellow wax) and white petrolatum in the

formula.


Absorption bases

A. It permits the incorporation of aqueous solutions resulting in the formation of

water-in-oil (W/O) emulsions.

• It also called non-emulsified base

• Commercial products,.

• Lanolin

• It is derived from sheep’s wool

• It is available forms of lanolin (wool fat) and hydrous lanolin (wool alcohols).

• Beeswax (white or yellow)

• Hydrophilic petrolatum

• Aquaphor and Aquabase


Absorption bases

B. W/O emulsions (emulsion bases) that permits the incorporation of additional

quantities of aqueous solutions (e.g., lanolin).

• Hydrous lanolin which contains 30% water.

• Cold cream

• These bases may be used as emollients.

• Less occlusion effect than oleaginous base.


Water-removable bases

• Water-removable bases are oil-in-water emulsions commonly called creams.

• They are easily washed from skin and are often called water-washable bases.

• Hydrophilic Ointment, USP


Water-soluble bases

• Water-soluble bases do not contain oleaginous components.

• They are completely water washable and often referred to as greaseless.

• Large amounts of aqueous solutions are not effectively incorporated into these

bases.

• They are acceptable for hand lotions, sun creams, shaving creams, and skin creams.

• Polyethylene glycol (PEG) ointment, NF, is an example of a water-soluble base.

• PEGs Mwt 200-600 are clear, Liquid

• PEGs Mwt 600-1000 are semisolid

• PEGs Mwt 1000-8000 are waxlike white material


Ointment bases

Ointment bases

Oleaginous Absorption Water/Oil Emulsion Oil/Water Emulsion

Water-miscible

Composition Oleaginous compounds

Oleaginousbase + w/o surfactant

Oleaginous base + water (< 45% w/w) + w/o surfactant (HLB <8)

Oleaginous base + water (> 45% w/w) + o/w surfactant (HLB >9)

Polyethylene Glycols (PEGs)

Water Content anhydrous anhydrous hydrous hydrous anhydrous, hydrous

Affinity for Water hydrophobic hydrophilic hydrophilic hydrophilic hydrophilic

Spreadability difficult difficult moderate to easy easy moderate to easy

Washability nonwashable nonwashable non- or poorly washable

washable washable


Ointment bases cont.

Ointment bases


Water-miscible

Drug Incorporation Potential

solids or oils (oil solubles only)

solids, oils, and aqueous solutions (small amounts)

solids, oils, and aqueous solutions (small amounts)

solid and aqueous solutions (small amounts)

solid and aqueous solutions

Occlusiveness yes yes sometimes no no

Uses protectants, emollients (+/-), vehicles for hydrolyzable drugs

protectants, emollients (+/-), vehicles for non-hydrolyzabledrugs

emollients, cleansing creams, vehicles non-hydrolyzabledrugs

emollients, vehicles non-hydrolyzabledrugs

drug vehicles


Ointment bases cont.

Ointment bases


Water-miscible

Examples White Petrolatum, White Ointment

Hydrophilic Petrolatum, Anhydrous Lanolin, Aquabase™, Aquaphor®, Polysorb®

Cold Cream type, Hydrous Lanolin, Rose Water Ointment, Hydrocream™, Eucerin®,Nivea®

Hydrophilic Ointment, Dermabase™, Velvachol®, Unibase®

PEG Ointment, Polybase™


Outlines

• Introduction

• Ointments bases



• Creams

• Pastes


Selection of the appropriate base

• Desired release rate of the drug substance from the ointment base

• Desirability of topical or percutaneous drug absorption

• Desirability of occlusion of moisture from the skin (as in case of psoriasis/dry skin)

• Stability of the drug in the ointment base

• Desire for a base easily removed by washing with water

• Characteristics of the surface to which it is applied


Outlines

• Introduction

• Ointments bases



• Incorporation

• Fusion

• Creams

• Pastes


Incorporation

• The components are mixed until a uniform preparation is attained

• On a small scale, the pharmacist may mix the components using a mortar and pestle,

or a spatula may be used to rub the ingredients together on an ointment slab.

• Some pharmacists use nonabsorbent parchment paper

• If the components of an ointment react with metal (as does iodine), hard rubber or

silicone spatulas may be used.


Incorporation cont.

• Levigation

• This is the term applied to the incorporation into the base of insoluble coarse

powders.

• It makes the ointment smooth and free from gritty sensation.

• Mineral oil for bases in which oils are the external phase

• Glycerin for bases in which water is the external phase

• It should be about equal in volume to the solid material.

• Mortar and pestle method is preferred when large volumes of liquid are added.


Incorporation cont.

• Others will use an ointment mill, an electronic mortar and pestle, or a device called

an Unguator.

• Or use of three roller mill


Fusion method

• All or some of the components of an ointment are combined by being melted

together and cooled with constant stirring until congealed.

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

• On a small scale, fusion may be conducted in a porcelain dish or glass beaker.

• This method is useful for beeswax, paraffin, and high molecular weight PEGs,

which do not lend themselves well to mixture by incorporation method.


Ophthalmic ointment

• Mixtures of mineral oil and white petrolatum are commonly used as the base in

medicated and non-medicated (lubricating) ophthalmic ointments.

• Sterile.

• It should be non-irritating to the eye

• It should having the ability to diffuse the medication throughout the secretions

bathing the eye.

• It must also have a softening point close to body temperature


Outlines

• Introduction

• Ointments bases

• Creams

• Pastes


Creams

• Pharmaceutical creams are semisolid preparations containing one or more medicinal

agents dissolved or dispersed in either

• A water-in-oil (W/O) emulsion (cold cream)

• An oil-in-water (O/W) emulsion (hydrophilic oint.)

• Vanishing creams are oil-in-water emulsions containing large percentages of water

and stearic acid or other oleaginous components.

• Creams find primary application in topical skin products and in products used on

mucous membranes, such as rectally and vaginally.


Creams cont.

• Many patients and physicians prefer creams to ointment.

• They have a relatively soft, spreadable consistency

• They are generally described as either nonwashable or washable

• They usually require the addition of a preservative(s)

• Preparation

• Usually involves separating the formula components into two portions: lipid and

aqueous

• The lipid portion contains all water-insoluble components and the aqueous

portion the water-soluble components.

• Both phases are heated


Outlines

• Introduction

• Ointments bases

• Creams

• Pastes


Pastes

• Pastes maybe defined as ointments incorporating a high percentage of insoluble

particulate solids, sometimes as much as or more than 50%.

• Pastes are less greasy than ointments

• Because of the stiffness, they remain in place after application.

• Pastes as such are not suited for application to hairy parts of the body.

• Examples of insoluble ingredients serving as the dispersed phase include starch and

zinc oxide.

• Pastes afford emollient action as do ointments.

• It absorb and neutralize certain harmful chemicals

• For the treatment of diaper rash

• It can often serve as a sunblock.


Thank you

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