university of limpopo b.pharm 2: pharmaceutics: dosage forms

RED GROUP.• Ali H. 201110680• Khoza M.C 201304139 • Bopape M.S 201417054• Malatji T.O 201414940• Mabika N.P 201407212• Mahlane K 201410009• Mashaba T.L 201000285• Madali N 2014 20006• Mahlatji M.D. 201400934• Marima R.C. 201323610• Seepe M.E 201307066• Swana M 201307253

Route of administration

Oral, Topical, Rectal and Parenteral.

Oral route of administration

Types of oral dosage forms • Solutions• Syrups• Suspensions• Emulsions

• tablets• Capsules• Granules• Powders

Method of administration

• Ingestion of a drug by mouth and into the GI tract

• Drug mouth esophagus GIT• Most medicines administered by the oral route provide

“immediate-release” drug delivery or “convenience” drug delivery.

Oral administration

Tablets and capsules

Advantages • Convenient .• Easy to handle and identify.

Disadvantages • Slow onset of action.• Difficulty in swallowing in children.

Solutions

Advantages • Easy to swallow.• Medicament is dispersed

homogeneously throughout the preparation.

Disadvantages • Bulky ( not convenient to carry).• Less microbiological and chemically

stable.

Suspensions

Advantages • It is most suitable for drugs having

unpleasant taste and odor.• Exhibits a high rate of bioavailability.

Disadvantages• Since it is a bulky product ,

transportation cost is high.• Microbial contamination easily takes

place.

Powders and granules

Advantages • It has a fast dissolution ability and

absorption.• Manufacturing is cheap.

Disadvantages • Dose inaccuracy.• It has an undesirable taste.

Emulsions

Advantages • Increased route of absorption• It is possible to include two

incompatible ingredients one in each phase of the emulsion.

Disadvantages • Preparation needs to be shaken well

before use.• Bulky(difficult to transport and

pronged to container breakage).

Application of suspensions

• Used in patients with difficulty in swallowing solid dosage forms.

• Used for conversion of soluble drug to insoluble form with pleasant taste.

• It is also applied for the process of prolonging drug action.

Applications of emulsions

• They are used in formulations of oil and water soluble drugs together.

• Used to increase the absorption of oils and oil soluble drugs through intestinal walls

• They enhance palatability of oils when given orally by distinguishing both taste and oiliness

• Used in TPN that help in delivering oily nutrients

Applications

• Can also be used in patients who are allergic to topical dosage forms, such as creams etc.

Topical administration• Application of the drug to the surface of the skin includes

administration of the drug to the mucus membrane of the eye, vagina, nose and ears.

Topical route: Dosage Forms• Ointments • Creams• Gels (Jellies)• Poultice• Pastes• Dusting powders• Transdermal patch:• Plasters• Liniments• Lotions• Paints• Pressurized dispensers (aerosol sprays)

Ointment Ointments are semi-solid, greasy preparations for application to the skin, rectum or nasal mucosa.Application: Ointments – bacterial skin infections. E.g. fucidin.

Advantages • Prolonged contact time between

the drug and the affected area• Odourless

Disadvantages• Bulkier than solid dosage forms• Greasy

Gels

Gels are semisolid emulsions in an alcohol base . Some will melt in body temperature and they tend to be drying Application:Gels (Jellies)-pain reliever e.g diclofenec sodium .

Advantages • Less greasy• Maximum absorption

Disadvantages • Not for drugs with larger particle

size.

Lotions

Are fluid preparations (aqueous) for external application without friction. They are usually oil mixed with water .Application: Lotions- skin rash. e.g. calamine.

Advantages• Compliance• No first-pass metabolism

Disadvantages• Denatured by dermis enzymes• Poor permeability of the drug to

deeper skin layers

Creams

Creams are semi-solid emulsions, that is mixtures of oil and water. They are divided into two types: oil- in- water (O/W) and water-in-oil (W/O).Application: Creams- vaginal candidiasis e.g. clotrimazole.

Advantages• Cost effective• Non invasive

Disadvantages• Easily contaminated• Reduced compliance due to

increased frequency of application

Paints

Paints are liquids for application to the skin or mucous membranes.Application: Paints- skin & nail infections. e.g. phenol 4.5%.

Advantages• Evaporates quickly to leave a dry

resinous film of medicament • High content of glycerol for

prolonged contact of the drug and the affected site

Disadvantages• Stains• Frequent application

Transdermal patch

A medicated adhesive patch that is placed on the skin to deliver a specific dose of medication through the skin and into the bloodstream.Application: Transdermal patch- contraceptives e.g. norgestrel.

Advantages • No pH variation, which seen in

GIT transit.• Can be removed easily and

quickly in cases of adverse reaction.

• Increased compliance.

Disadvantages • Leaves adhesive residue on the

skin surface.• Can be irritating to the skin as it

may be placed for up to 7 days.

Aerosols

Pressurised dosage form in which a drug is dissolved, dispersed or suspended in compressed or liquified gas to expel the drug from the container in a spray form.Application: Pressurized dispensers (aerosol sprays)- Pain: sunburn. Lidocaine.

Advantages • Readily absorbed• Dose can be removed without

contamination

Disadvantages• Flammable• Reduced effectiveness with

incorrect use

Application of other Topical dosage forms• Poultice- inflammation e.g. Kaolin poultice• Pastes - minor skin irritation. i.e. cuts and burns. e.g. zinc oxide.• Dusting powders- cutaneous candidiasis. e.g. fluconazole• Plasters – s.t corns and warts. e.g. salicylic acid. • Liniments- muscle or joint pain- chilli.

Method of administration

• Clean the affected area well

• Pat skin dry

• Apply thinly and evenly to the affected area

• Gently massage / rub formulation into the skin until it has disappeared

• With lotions one can use a cotton to apply the medication, this is to avoid

bruising the skin

• Aerosol are sprayed evenly and thinly to the surface of the skin

Rectal route of administration

suppository

• A solid medical preparation in a roughly conical or cylindrical shape, designed to be inserted into the rectum or vagina,where it melts at body temperature and dissolves.

• E.g Dulcolax suppository

Applications

• Used in instances where the patient is unable to swallow oral dosage forms such as unconscious patients, young children, geriatrics, mentally disturbed patients and patients with dysphagia.

• Also used in cases when administrated orally, causes nausea and vomiting.

• GIT obstruction and impaired absorption

Method of administration

• The drug preparation is inserted into the rectum, which is the site of drug release, where it either brings about a local effect or is absorbed to act systemically.

• Remove suppository from its package.• Insert small tapered end first with index finger for the full

length of the finger. • May need to be lubricated with a water-soluble gel to ease

insertion.

Cont’d

Suppository

Advantages• Can be used for systemic

absorption of drugs and avoid first-pass metabolism

• When oral administration of a drug is not suitable as in infants or patients suffering from nausea, vomiting and gastrointestinal disturbances.

Disadvantages• Suppositories are not suitable for

patients suffering from diarrhoea• Incomplete absorption may be

obtained because suppository usually promotes evacuation of the bowel.

• Can cause local irritation on rectal mucosa

Enema

• An enema is the procedure of introducing liquids into the rectum and colon via the anus.

• There four types enema commonly administered: cleansing, return flow, medicated and oil retention.

• E.g. Neomycin enemaHydrocortisone enema

applications

• Constipation• Inflammatory bowel disease• Rehydration therapy in patients for whom intravenous therapy

is not applicable• To cleanse the colon before a surgical procedure or colon

examination.

Method of application

• Before administering the enema, position the patient on their left side and flex their right knee.

• The tube is then inserted into the rectum and the liquid is administered in small increments.

Enema

Advantages• Can be used when a local effect is

desired. • Can be used to bring about a

systemic effect, thus little to no first pass metabolism of the drug occurs.

Disadvantages• Barium enema generally is not as

accurate as colonoscopy or virtual colonoscopy

• Tap water, used in cleansing enemas, is hypotonic therefore causing electrolyte imbalance.

• Disliked by patients.

Parenteral Route of Administration

Parenteral Route of Administration

• They include dosage forms that are implanted, injected or infused directly into vessels, tissues, tissue spaces or body compartments.

• It is often used for drugs that cannot be given orally due to: Patient intolerance. Instability of the drug. Poor absorption if taken orally.

Pros and Cons

Advantages • Rapid onset of action. • No first pass metabolism. • Drug delivery to unconscious patients. Disadvantages • Irritation to site of administration. • Reduced patient compliance.

Route of Administration Definition Application

Intravenous They are administered into easily accessible veins near the surface of the skin.

Promethazine hydrochloride in acute anaphylaxis

Intramuscular They are administered directly into the muscles.

Adrenaline in Asthma attack

Intra-arterial Intra-arterial injections are administered into arteries

Streptokinase for Embolism

Subcutaneous They are administered into the fat layer directly beneath the skin.

Insulin for diabetic patients

Intradermal Drug is given within the skin layers. Drug sensitivity testing, e.g. penicillin

Intrathecal Injection of a drug into the spinal canal to reach the cerebrospinal fluid.

Methotrexate for Cancer

Dosage Forms

• Implants • Solutions

Dosage Forms cont’

• Suspensions • Emulsions

Dosage Forms cont’

• Dry powder

Dosage form Advantages Disadvantages

Dry powders • Easy formulation and development • Not marketed as ready-to-use

Suspensions • suitable for insoluble drugs• increase chemical stability

• Drug release is based on viscosity and solubility

• Difficult formulation and manufacture

Solutions • Used for rapid correction of electrolyte imbalance

• Reduced drug stability

Implants • Drug release can be traced and predictable

• Area of implantation can be infected

• Insertion requires specialized knowledge

emulsions • A vehicle for drugs intended for prolonged release

• Used to provide a concentrated source of calories and essential oil

• Liable to microbial contamination which can lead to cracking

• Storage conditions may affect stability

Method of Administration Wash your hands with a soap Wear sterile gloves Select and cleanse target area with an alcohol swab and allow alcohol to dry Prepare the syringe -remove needle guard -express any air bubbles from syringe -check amount of solution in the syringe Inject -place the needle close to the skin with the hole facing up -insert the needle at proper angle -slowly administer the medication Withdraw needle -place cotton above puncture site(not on the needle) -slowly remove the needle

References• Aulton M.E.2007.Pharmaceutics:The design and manufacture of

medicines.3rd Ed.Church Hill Livingstone.Elsevier:USA.• Aulton,M.E & Taylor,K.M.G,.2013.Pharmaceutics:The design and

manufacture of medicines.4th Ed.ChurchHill Livingstone.Elsevier.USA• Bentz,P.M.& Euis,J.R.2007.Modules for basic nursing skills.7th

Ed.Philadelphia:Lippincott williams&Wilkins.• Winfield A.J. Rees A.J. Smith I. 2009. Pharmaceutical practice. 4th Ed.

Churchill Livingstone: USA