Evaluation of topical dosage

forms

Zohre jelodarian

School of pharmacy , Kermanshah University of Medical Sciences , Krmanshah , Iran

Topical delivery includes two basic types of product: 1. External topicals that are spread, sprayed, or otherwise dispersed on to cutaneous tissues to cover the affected area.2. Internal topicals that are applied to the mucous membrane orally, vaginally or on anorectal tissues for local activity.

Advantages of Topical Drug Delivery Systems

Avoidance of first pass metabolism.Convenient and easy to apply.Avoidance of the risks and inconveniences of

intravenous therapy and of the varied conditions of absorption, like pH changes, presence of enzymes, gastric emptying time etc.

Achievement of efficacy with lower total daily dosage of drug by continuous drug input.

Avoids fluctuation in drug levels, inter- and intrapatient variations.

Ability to easily terminate the medications, when needed.

A relatively large area of application in comparison with buccal or nasal cavity

Ability to deliver drug more selectively to a specific site.

Avoidance of gastro-intestinal incompatibility.Providing utilization of drugs with short biological

half-life, narrow therapeutic window. Improving physiological and pharmacological

response. Improve patient compliance.Provide suitability for self-medication.

Disadvantages of Topical Drug Delivery Systems

• Skin irritation of contact dermatitis may occur due to the drug and/or excipients.

• Poor permeability of some drugs through the skin. • Possibility of allergenic reactions.• Can be used only for drugs which require very small

plasma concentration for action• Enzyme in epidermis may denature the drugs• Drugs of larger particle size not easy

to absorb through the skin

Topical dosage forms

Solid

powder

Aerosol

Plaster

Liquid

Lotion

Liniment

Solution

Emulsion

Suspension

Aerosol

Semi solid

Ointment

Cream

Paste

Gel

Jelly

Suppository

The layers of skin

o Stratum Germinativum (Growing Layer)

o Malpighion Layer (pigment Layer)

o Stratum Spinosum (Prickly cell Layer)

o Stratum Granulosum (Granular Layer)

o Stratum Lucidumo Stratum Corneum (Horny

Layer)

The layers of epidermis

Evaluation Of Topical Dosage Form

Evalution of patch

21-day cumulative irritancy patch test

Kligman “maximization” test

Draize-shelanski repeat-insult patch test

Evaluation Of Topical Dosage Form

Evaluation of ointmentsPenetration

Rate of release of medicaments

Absorption of medicaments into blood stream

Irritant effect

Evaluation Of Topical Dosage Form

Evaluation of cream

Rheology

Sensitivity

Biological testing

Evaluation Of Topical Dosage Form

Evaluation of emulsions

Phase separation

Globule size

Rheological properties

Effect of thermal stresses

Evaluation Of Topical Dosage FormEvaluation of paste

Abrasiveness

Particle size

Cleansing property

Consistency

pH of the product

Foaming character

Limit test for arsenic and lead

Volatile matters and moisture

Effect of special ingredients

Evaluation Of Topical Dosage FormEvaluation of powder

Shade control and lighting

Pressure testing

Breakage test

Flow property

Particle size and abrasiveness

Dispersion of color

Evaluation Of Topical Dosage FormEvaluation suspension

Sedimentation volume

Rheologic methods

Electrokinetic techniques

Particle size changes

Evaluation Of Topical Dosage FormEvaluation of aerosol

Flame projection

Flash point

Vapor pressure

Density

Moisture

Aerosol valve discharge rate

Spray patterns

Dosage with metered valves

Net contents

Foam stability

Particle size determination

Evaluation Of Topical Dosage Form

Evaluation of lotion

Antiseptic property

Determination of alcohol content

Evaluation Of Topical Dosage FormEvaluation of gel

Drug content

Homogeneity of drug content

Measurement of pH

Viscosity

Spreadability

Extrudability

Brookfield viscometer(RVT)

Evaluation Of Topical Dosage Form

Evaluation of suppository

Melting range test

Dissolution test

Liquefaction or softening time test

Thanks for your

attention