Classification of Dosage Forms - The Pharma Education

Introduction and Classification of Dosage Forms

Introduction and classification of dosage forms. The administration of drugs in pure form is usually difficult and undesirable. At the same time, therapeutic considerations make it desirable that the drugs are not administered to the patients in their original form. In order to make a drug administrable to the patient, it is converted into a dosage form by mixing it with some non-drug components (Excipients or Additives).
Read More about List of Excipients/Additives

The form in which drug substances are presented in the market is called the dosage forms.
A dosage form may be solid, semisolid, liquid, or gas and contains a definite quantity of drug(s) along with or without excipients.
The same drug can be formulated in several dosage forms for presentation in the market.
E.g. Diclofenac gel, Diclofenac tablet, Diclofenac injection etc.

The need for dosage forms:

• Accurate dose.
• Protection e.g. coated tablets, sealed ampules.
• Protection from gastric juice.
• Masking the taste and odor.
• Placement of drugs within body tissues.
• Sustained and Controlled release medication.
• Optimal drug action.
• Insertion of drugs into body cavities (rectal, vaginal).
• Use of the desired vehicle for poorly soluble or insoluble drugs.

The desirable properties of a dosage form:

• It should be convenient to handle, use, and store.
• For better patient compliance, it should not disturb his routine life cycle as for as possible and should be acceptable aesthetically, organoleptically, therapeutically, and from an economic standpoint.
• It should be stable during storage (shelf-life) and use.
• The physical, chemical and therapeutic integrity of the dosage form should be maintained during storage.
• The dosage form should be free from an interaction between components, with packaging materials and environmental factors (heat, humidity, oxygen, light).
• It should also withstand mechanical shock during transportation.
• The dosage form must retain its size, shape, appearance, taste, flavor, and therapeutic effect during the stipulated shelf-life.
• The dosage form should be presented in different drug strengths providing the flexibility of dose to suit different age groups (e.g. 50, 100, 200, 500 mg tablet of the same drug) or for different disease conditions.
• It should provide the anticipated therapeutic effect.
  The extent and drug release pattern, onset, intensity, and duration of action should be predictable.
• It should protect the drug substance and conceal the disagreeable taste or odor.
• It should be economical and presentation should be elegant.
• It should permit easy identification through distinct color, shape, or identification marking(s).

Classification of Dosage Forms

Dosage forms can be classified in many ways on the basis of their physical state, route of administration, intended purpose or site of application, etc.
Physical state: Solid, Semisolid, Liquid, Gaseous.
Route of administration: Oral, Parenteral, Rectal, Nasal, Vaginal, Urethral, etc.
Site of Application: Skin, Eye, Tooth, Hand, Foot, Hair, Nose.
Use: Internal, External.
However, classification based on physical state and route of administration is most commonly used.

Examples of Dosage Forms

PHYSICAL STATE

• Solid – Powders, Granules, Tablets, Capsules, Pills, Cachets, etc.
• Semisolid – Ointment, Cream, Suppositories, Paste, etc.
• Liquid – Solutions, Elixirs, Emulsions, Suspensions, Syrups, Spirits, etc.
• Gaseous – Inhalants, Aerosols, etc.

ROUTE OF ADMINISTRATION

• Oral – Powders, Tablets, Capsules, Elixirs, Solutions, Emulsions, Syrups, etc.
• Parenteral – Solutions, Suspensions, Emulsions
• Rectal – Suppositories, Enemas, Ointments
• Transdermal – Ointments, Creams, Powders, Pastes, Lotions, etc.
• Intranasal – Solutions, Sprays, Inhalations
• Vaginal – Suppositories, Tablets, Ointments, Creams, etc.
• Urethral – Suppositories
• Sublingual – Tablets, Lozenges
• Conjunctival – Ointments
• Intraocular – Solutions, Suspensions, Ointments
• Intrarespiratory – Aerosols

SITE OF APPLICATION

• Skin – Lotion, Liniment, Cream, Powder, etc.
• Eye – Eye drop, Eye ointment, etc.
• Tooth – Toothpaste etc.
• Foot – Foot powder etc.
• Hair – Shampoo, Hair oil, etc.
• Nose – Nasal drops, etc.

USE

• Internal – Tablet, Capsules, Syrup, etc.
• External – Lotion, Liniment, Cream, Ointment, etc.

Quick Links

Inactive Ingredient Search for Approved Drug Products
List of Additives