Routes of Medication Administration Bladen Community College Pharmacy

Routes of Medication Administration Bladen Community College Pharmacy Technician Summer 2011

Routes & Forms Introduction • The way the body absorbs and distributes drugs varies with the route of administration and the dosage form used. • Routes of administration are usually classified by application location • Dosage routes are classified as enteral or parenteral. • For each route of administration, there are various formulations used to deliver the drug via that route.

Local effect: when drug activity is at the site of administration. Systemic effect: when a drug is introduced into the venous (circulatory) system and carried to the site of activity.

Enteral refers to anything involving the alimentary tract, i. e. , from the mouth to the rectum. This tract is involved with digesting foods, absorbing nutrients, and eliminating unabsorbed wastes. There are four enteral routes of administration: 1. Oral 2. Sublingual 3. Buccal 4. Rectal

Enteral Routes • • Oral Sublingual Buccal Rectal • Stomach and intestine • Under the tongue • Inside the cheek • Rectum

Dosage Forms Enteral Route • Oral • Buccol • Sublingual • Rectal Dosage Form • Tablets * capsules * Bulk powder * solutions suspensions * elixirs * syrups* emulsions • Tablets * solutions • Tablets * lozenges • Solutions * ointments * suppositories

Intraocular v. The EYE v. Drugs are administered to the eye for LOCAL TREATMENT of various eye conditions and for anesthesia. v. A major problem of ophthalmic administration is the immediate loss of a dose by nature spillage from the eye.

Intraocular v. Tips for Using v Avoid eye make-up Ophthalmic Drops: Keep while using eye in mind that this is a solutions. sterile solution. v Use a mirror when Contamination of the applying the drops, or eye dropper or eye have someone help solution can lead to a instill the eye drops. serious eye infection. v. If irritation persists or increases, discontinue use immediately.

Intraocular Dosage Forms v. Solutions v. Suspensions v. Ointments v. Inserts

INTRANASAL • The adult nasal cavity has a capacity of about 20 ml, a very large surface area for absorption, and a very rich blood supply. • The intranasal absorption of some drugs produces blood concentrations similar to when the drug is intravenously administered. • Most intranasal formulations are used for their decongestant activity on the nasal mucosa

Continue Intranasal • Intranasal formulations include solutions, suspensions, ointments, and gels. • If the drug is sufficiently volatile, it can be administered in a nasal inhaler. • Intranasal dosage forms should not be used for prolonged periods.

Intranasal Devices Included: Nasal Spray Nasal Aerosol Nasal Inhaler

Buccal

v Buccal is an enteral route…………… v Dosage forms… • Tablets: Hard formulations in which drug and other ingredients are machine compressed under high pressure into shape. • Solutions: A clear liquid made up of one or more ingredients dissolved into a solvent

Buccal tablets and lozenges are placed in the pouch between the cheeks and the teeth to dissolve v

SUBLINGUAL Sublingual is derived from Latin and literally means ‘under the tongue. ’ It refers to the route of administration by which drugs can be taken. Drugs are placed underneath the tongue so that they can be absorbed directly into the small blood vessels that lie there.

The sublingual route has certain advantages over other routes of administration because it is often faster as the drug is absorbed directly into the bloodstream. It also ensures that the drug is only broken down by salivary enzymes. If a drug were to be taken orally, it would have to survive the acid, bile, and enzymes of the stomach, liver, and intestines before finally entering the bloodstream. However, many drugs cannot be taken sublingually because they are not absorbed completely or are absorbed too quickly.

Dermal • The skin is the largest and heaviest organ in the body and accounts for about 17% • Most dermal dosage forms are used for local effects on or within the skin • Dermal administration has a number of advantages • Ease of administration not found in other routes • Continuous drug delivery • Easily removed if necessary • Disadvantage; amount of drug that can be absorbed is limited to about 2 mg/hour.

Dermal Formulations • The skin is composed of 3 layers; Øepidermis Øsubcutaneous tissue • The absorption of drugs through the skin is called “Percutaneous Absorption. ”

Dermal Formulations • • • Solutions, Tinctures, Collodions, and Liniments Ointments, Creams, Gels, and Lotions Pastes, Plasters, and Powders Transdermal Patches, Tapes, and Gauzes Aerosols

Inhalation • Inhalation dosage forms are intended to deliver drugs to the pulmonary system (lungs). • Gaseous or volatile anesthetics are the most important drugs administered via this route. • Most inhalation dosage forms are MDI aerosols that depend on the power of compressed or liquefied gas to expel the drug from a container. • Particle size is the critical factor with these dosage forms.

Inhalation Devices • • Metered Dose Inhaler (MDI) Aerosols Adapters and Spacers Dry Powder Inhalers Atomizers and Nebulizers

Oral Formulations • Oral administration is the most frequently used route of administration. • When formulations are orally administered, they enter the stomach, which is very acidic. • Drugs administered in liquid dosage forms generally reach the circulatory system faster than drugs formulated in solid dosage forms.

Gastrointestinal action • The disintegration and dissolution of tablets, capsules, and powders generally begins in the stomach, but continue to occur when the stomach empties into the intestine. • Enteric coated tablets are used when the drug can be degraded by the stomach acid. • The enteric coating will not let the tablet disintegrate until it reaches the higher p. Hs of the intestines.

Solid formulations • Tablets are hard formulations in which drug and other ingredients are machine compressed under high pressure into a shape. • Capsules contain drug and the other ingredient packaged in a gelatin shell. • Bulk powders contain the active drug in a small powder paper or foil envelope.

Liquid formulations • Solution is a clear liquid made up of one or more ingredients dissolved in a solvent. • Syrups are concentrated or nearly saturated solutions of sucrose in water. • No aqueous solutions are those solutions which predominately contain solvents other than water, either alone or addition in water. • Elixirs are clear, sweetened, hydro alcoholic liquids intended for oral use. • Spirits or essence are alcoholic or hydro alcoholic solutions of volatile substances with alcohol substances ranging from 62%-85%. • Tinctures are alcoholic or hydro alcoholic solution of nonvolatile substances. • Suspensions are formations in which the drug does not completely dissolve in the solvent.

Intravenons • Intravenous dosage forms are administerd directly into a vein and therefore the circulating blood. Eulsions are formulations that contain both aqueous, nonaqueos componets. it takes about 20 secounds for intravenous administerddrugs to circulate throughout the body.

Devices • • SYRINGES INFUSION PUMPS ELASTOMERIC PUMPS

Intramuscular • Intramuscular injections are often given to patients who are unable to take there medications by mouth. • Intramuscular injections are also used as a route for medications that are poorly absorbed by the gastrointestinal tract. • Intramuscular drugs are often considered less harmful and easier to use than the intravenous route. • Drugs for intramuscular injections are often formulated as: – – – Solutions Suspensions Colloids Oil-in-water emulsions Water-in-oil emulsions

Intramuscular Injuries • • • Abscesses Cysts Embolism Hematoma Skin Sloughing Scar Formation

Intramuscular Injection Sites • Needles used for injection sites are generally 1 in. To 1. 5 inches long and are generally 19 to 22 gauge in size. • Generally only limited volumes can be given IM. – 2 ml in the deltoid and thigh muscles – 5 ml in the gluteus maximus • The principal sites for injections are: – Gluteal maximus (buttocks) – Deltoid (upper arm) – Vastus lateralis (thigh)

Vaginal • Both Enteral & Parenteral Route • Cylinder like organ that leads from the cerix and uterus to an external opening. • Most used for local effect. Long term systemic effect can be achieved with IUD’s • • Solutions Powders Ointments Creams Aerosol foams Suppositories Tablets IUD

Rectal • Drugs are administered to the rectum for local effect or to avoid degradation after oral administration. • Also if the patient is vomiting, unconscious, or incapable of swallowing oral formulations. • Local effects may include the soothing of inflamed hemorrhoidal tissues or promoting laxation. • Degradation comes from stomach acid or intestinal enzymes.

Rectal administration is used to achieve a variety of systemic effects including asthma control, antinausea, motion sickness, and antiinfective therapy. • The most common rectal administration dosage forms are suppositories, solutions, and ointments. • Suppositories are semisolid dosage forms that dissolve in the rectum. • Solutions are used as enemas. • Ointments are spread around the anal opening. • Disadvantages of rectal dosage forms are: • Not preferred by most patients. • They are inconvenient • Rectal absorption of most drugs are frequently erratic and unpredictable.

Subcutaneous • Subcutaneous means under the skin

Absorption • Subcutaneous administration usually provides slower absorption compared to intramuscular administration • Subcutaneous administration provides faster absorption compared to oral administration

Other drugs administered SC • Heparin • Vaccines • enoxaparin

Implants • Preferred route of administration for implants

Routes of Administration • • Solutions Suspensions Emulsions Implants