LECTURE 5

Mark true (T) or false (F):1) Pharmacy profession is concerned with the

preparation and dispensing of drugs only.

2) The golden triad consists of the physician, the pharmacist and the patient.

3) Pharmacognosy is the science concerned with the study of drugs of natural origin.

4) Chemical name of drug reflects the pharmacologic characteristics of drug.

5) The protein-bound drug is inactive and not subjected to metabolism or excretion.

Choose the correct answer: Insulin is a drug of: 1) Plant source.2) Mineral source.3) Animal source.4) Microorganisms source. A minimum concentration of a drug

needed at a receptor to produce response is defined as:

1) MEC.2) MTC.3) Therapeutic effectiveness.4) Bioavailability.

Therapeutic alternatives are drug products that

contain different active ingredients but of the same

1) Chemical structure.

2) Bioavailability.

3) Pharmacologic class.

4) Non of the above.

Parenteral route has many disadvantages such as:

1) Rapid response.

2) Invasive and painful.

3) Required sterile technique.

4) 2,3.

Dosage forms are needed for the following reasons:

1) For the protection of a drug substance from the destructive effect of air and humidity (ampoules).

2) For the protection of a drug substance from destruction by gastric acid after oral administration (enteric-coated tablets)

3) To avoid bitter or offensive taste or odor of a drug substance (capsules, coated tablets).

Pharmaceutical dosage forms

4) To provide liquid preparations of substances that are insoluble in the desired vehicle (suspensions).

5) To provide time-controlled drug action.

6) To provide optimal drug action from topical administration sites (creams).

7) To provide for insertion of a drug into body’s orifices (suppositories).

8) To provide for the placement of drugs directly into bloodstream (injections).

I. Liquid dosage forms.

II. Solid dosage forms.

III.Semi-solid dosage forms.

IV. Miscellaneous dosage forms.

Classification of dosage forms

They are often the dosage form of choice because:

1) They are more quickly effective than a solid

dosage form.

2) They are easier to swallow than solid dosage

forms (pediatric and geriatric).

3) Certain substances can be given only in a liquid

form.

I-Liquid dosage forms

4) Certain chemical substances may cause

pain (e.g. potassium iodide) or gastric

irritation (e.g. aspirin) when

administered in a solid state.

5) Uniformity and flexibility of dosage are

easily obtained in liquid dosage form.

6) The dosage form of choice in certain

types of pathological condition.

Disadvantages:

1) They are liable to deterioration faster than

solid dosage forms.

2) They present many flavoring and

sweetening problems.

3) Many incompatibilities arise because of

interaction between dissolved species.

4) Provide excellent media for bacterial

growth.

5) Many interactions arise because of changes

in solubility produced by solvent alteration.

The major classes of liquid pharmaceutical dosage forms are:

A. Liquid dosage forms containing soluble matter:

Consist of one or several soluble substances (solute) dissolved in water (solvent).

Solute: solid, liquid or gas.

Solvent: water-miscible liquid.

B. Liquid dosage form containing insoluble matter:

Insoluble solutes may be suspended in a vehicle.

Examples: suspensions and emulsions.

Suspensions:Consist of a two-phase system in which

the internal phase is solid and the external phase is liquid.

The liquid phase in most pharmaceutical suspensions is aqueous.

Emulsions:Consist of a heterogeneous system of at

least one immiscible liquid dispersed in another in the form of droplets.

The system is stabilized by emulsifying agent.

Suspension Emulsion

Ear drops:

The drug, or mixture of drugs, is presented

as a solution or suspension in a suitable

vehicle such as water, glycerol or alcohol.

Ear drops containing antibiotics used to

treat or prevent infections in the outer ear

and ear canal.

Ear drops containing sodium bicarbonate

in water or (sodium bicarbonate + glycerin)

used to remove excess wax.

Eye drops:

These are sterile preparations.

Depending on the condition being treated,

they may contain

Antibiotics and steroids to treat eye infection

or used as prophylactic to prevent infections

after eye surgeries.

Antihistaminics and NSAI to treat eye allergy.

B-blocker to treat glaucoma.

Nasal drops:

These are isotonic solutions.

Nasal drops can have ingredients to

provide relief in conditions such as an

allergy, common cold, or a sinus problem.

Locally acting decongestants are

commonly presented as nose drops.

It works by contracting dilated blood

vessels in the nasal tissues and reducing

the flow of secretion.

Gargles:Used to treat infections of the throat.They are presented in concentrated form

and diluted at time of use.Should not be swallowed but held in the

throat while exhaling through the liquid.

Mouthwashes:Similar to gargles but are used to treat

conditions of the mouth.The active ingredients are usually

antiseptic or bactericidal agents.

Elixirs:

Is a solution of one or more drugs.

The vehicle generally contains a high

proportion of sucrose or , nowadays, a

“sugar-free” vehicle as sorbitol solution,

which is less likely to cause dental caries.

They include antihistamines, antibiotics,

decongestants and expectorant.

Liniments:

These are liquid for external use.

They are used to alleviate the discomfort of

muscle strain or arthritis.

Are formulated from alcohol, acetone, or

similar quickly evaporating solvents and

contain counterirritant aromatic chemical

compounds such as methyl salicylate and

turpentine oil.

Lotions:These are liquid of low-to-medium viscosity for

external use.May be solutions, suspensions or emulsions.Lotions can be used for the delivery to the skin of

medications such as: Antibiotics. Antiseptics. Antifungal. Corticosteroids. Anti-acne agents. Soothing, moisturizing or protective agents (such

as calamine).

Paints:

Are solutions for application to the skin or

mucous membrane.

Those used on the skin are often

formulated with a volatile vehicle which

evaporates on applications and leaves a

film of active ingredient on the skin

surface.

Paints used on the throat and mucous

surface include a viscous vehicle such as

glycerol, which enables the preparation

to remain contact with the affected area.

Paints are used for their antiseptic,

analgesic or astringent properties.

Should be applied with a brush to assist

application.