Routes of Drug Administration and Dosage Formulations Created by Jennifer Majeske, Mineral Area...

Created by Jennifer Majeske, Mineral Area College

CHAPTER 4Routes of Drug Administration and

Dosage Formulations


LEARNING OBJECTIVES Differentiate between the terms route of

administration, dosage form, and drug delivery system.

Explain the properties of oral, topical, and parenteral dosage forms.

Identify inactive ingredients and the various coatings of tablets and their functions.

Differentiate between a suspension and an emulsion liquid dosage form.

Identify dosage formulations utilizing the transmucosal route of administration.


LEARNING OBJECTIVES Define the emulsion characteristics of

topical products such as ointments, creams, lotions, and gels.

Explain the advantages and disadvantages of oral, topical, and parenteral dosage formulations.

Discuss the importance of syringe selection for a diabetic patient.

Contrast the advantages and disadvantages for insulin in multi-dose vials and prefilled insulin syringes.


LEARNING OBJECTIVES Understand the stability and expiration

dates of insulin at room and refrigerated temperatures.

Demonstrate correct techniques for administration of eyedrops, eardrops, metered-dose inhalers, and various parenteral injections.

Differentiate among enteric-coated, sustained-release, and extended-release dosage formulations.


INTRODUCTION There exists many pharmacological agents

with a variety dosage forms available to customize patient treatment.

Pharmaceutics – the study of the release characteristics of various dosage forms or drug formulations.

Medications can be taken: orally, inhaled, injected, inserted, applied to the skin, and each route affects the drugs’ onset and duration of action.

Pharmacokinetics – the study of how drugs are absorbed, distributed, metabolized, and eliminated.


ROUTES OF ADMINISTRATION Route of administration – a way to get a

drug into or onto the body. What are the major routes of

administration? Dosage form – the physical manifestation

of a drug – such as a tablet, capsule, suspension, ointment, cream, patch or injection – that is designed to deliver the medication by one or more routes of administration.

Systemic effect – the series of steps to get a drug into the bloodstream to exert its therapeutic effect.


ROUTES OF ADMINISTRATION Delayed systemic effect:

Tablets, capsules, and oral liquids Immediate systemic effect:

Parenteral injections, IV bolus and infusions Localized effect – when a drug exerts

its pharmacological action at or near the site of administration.Drugs administered by the

transmucosal, topical and inhalation route

Example: eardrop in the ear


ORAL ROUTE OF ADMINISTRATION Oral route of administration –

medication administered for absorption along the gastrointestinal (GI) tract into the systemic circulation.

Oral can also refer to applying medication to the mouth.

The abbreviation po – from the Latin term per os, meaning “by mouth”, is used to indicate the oral route of medication on a prescription.


ORAL DOSAGE FORMS Tablets, capsules, solutions,

suspensions, syrups and elixirs. Tablets and capsules are the two most

common types and are inexpensive to manufacturer.

The active ingredient in many tablets, capsules and suspensions are sometimes powders or granules.

Drugs available in salt forms add shelf life to the product and/or to affect the release characteristics of the drug.


TABLETS Tablet – a solid dosage form produced

by compression. Tablets contain one or more active

ingredient along with inert or inactive ingredients (excipients).

Tablets are available in a variety of shapes, sizes, surface markings and coatings.


TYPES OF TABLETS Tablets can be designed to be easy to

swallow, mask taste or exert an immediate pharmacological effect.

Compression tablets are the most inexpensive and common dosage form. Acetaminophen (Tylenol)

Multiple compression tablet (MCT) is made by multiple compression cycles and is a tablet on top of a tablet or a tablet within a tablet.

Caplet – a hybrid of a capsule and tablet; shaped like a tablet, coated like a capsule.


TABLET COATINGS Most compression tablets are not coated. Coatings improve flavor, appearance, or ease

of swallowing. Sugar-coated tablet (SCT) – contains an

outside layer of sugar that protects the medication and improves appearance and flavor.

Sugar coating makes tablets larger and heavier thus more difficult to swallow.

Film-coated tablet (FCT) – contains a thin outer layer of a polymer that can either be soluble or insoluble.

Film coating are colored for an attractive appearance; taste-masking benefits can be lost if crushed.


SPECIAL DOSAGE FORMS Most tablets are designed to be

swallowed whole and dissolve in the GI tract.Chewable tablet – contains a base that is

flavored and/or colored. It is designed to be chewed (masticated) and absorbed quickly for slightly faster onset.

Oral disintegrating tablet (ODT) – designed to melt in your mouth. ODT’s are useful for pediatric and geriatric patients who may have difficulty swallowing or for patients with nausea.


CAPSULES The active ingredient of a capsule is in

the form of a granular powder (liquid gel) enclosed by a gelatin shell.

The body and cap may be sealed to prevent tampering.

Diluent – pharmacologically inert filler used in capsules.

Some capsule formulations are designed to provide better absorption of drugs, with less side effects.

Some medications that come in capsule form are substitutable with a tablet, others are not.


POWDERS AND EFFERVESCENT SALTS Powders and effervescent salts are used

less frequently by patients, but offer some advantages over tablets and capsules.

Powders – preparations in the form of fine particles. Goody’s headache powders

Effervescent salts – granules or coarse powders containing one or more medicinal agents, as well as some combination of sodium bicarbonate with citric acid, tartaric acid or sodium bisphosphate.Alka-Seltzer


LIQUIDS Liquids – consist of one or more active

ingredient in a liquid vehicle such as a solution or suspension.

Most liquids are commercially available as solutions (elixirs and syrups), suspensions or emulsions.


COMMON SOLUTIONS Solution – a liquid in which the active

ingredients are completely dissolved in a liquid vehicle.

Solutions can be classified as aqueous, alcoholic, or hydroalcoholic.

Solvent – the vehicle that makes up the greater part of the solution.

Solute – the ingredient dissolved in a solution.


COMMON SOLUTIONS Solutions are often classified by their

ingredients; elixirs and syrups are the most common dosage forms of solutions.

Elixir – a clear, sweetened, flavored solution containing water and ethanol.

Syrup – an aqueous solution thickened with a large amount of sugar – sucrose – or sugar substitute.

Syrups can contain additional flavors, colors or aromatics.

Most pediatric formulations are syrups or elixirs.


LESS COMMON SOLUTIONS Aromatic water – a solution of water containing

oils or other substitutes that have a pungent, and usually pleasing smell.

Extract – potent dosage form derived from plant or animal sources which most or all of the solvent has evaporated to produce a powder, an ointment like form, or a solid.

Fluidextract – a liquid dosage form prepared by extraction from plant sources and commonly used in the formulation of syrups.

Tincture – alcoholic or hydroalcoholic solution of extractions from plants.

Spirit – alcoholic or hydroalcoholic solution containing volatile, aromatic ingredients.


SUSPENSIONS Suspension – the state of a substance

when its solid particles are mixed with but undissolved in a liquid.

Dispersion – the medication is simply dispersed or distributed throughout the vehicle, creating an incomplete mixture of solid and liquid.

Suspensions contain inactive ingredients such as colorings, flavorings and coatings.

Some suspensions are commercially available, others come in the form of powders that must be reconstituted prior to dispensing.


EMULSIONS Emulsion – another type of dispersion;

a mixture of two immiscible or unblendable substances.

What is an example of an emulsion? Emulsions contain an emulsifying agent

that renders the emulsion stable and less prone to separate.


COLLOIDS Colloid – a mixture having physical

properties between those of a solution and a fine suspension.

Magma – or milk like liquid, is an example of a dispersion containing ultrafine colloidal particles that remain distinct in a two-phase system.

Microemulsion – another type of colloidal dispersion; a liquid that is dispersed in another.


ADVANTAGES AND DISADVANTAGES OF CERTAIN ORAL DOSAGE FORMS

What are some common advantages and disadvantages to administering a drug using the oral route?

Tablets Capsules Liquids


DISPENSING AND ADMINISTRATION OF ORAL DOSAGE FORMS

Patients should be counseled by the pharmacist what drinks and foods to take or not take with medications.

Patients should be counseled by the pharmacist on behaviors to avoid while taking medications.

Auxiliary labels are affixed to drug containers to ensure that patients are taking medications in the correct manner.

Patients should be reminded of proper storage conditions.


ORAL SYRINGES Oral syringe – measures and delivers

oral liquid medications to pediatric patients.

This type of syringe is a calibrated device consisting of a plunger and cannula, and is used without a needle to administer medications to the mouth.

Oral syringes can be used to slowly administer liquid medications.

Very small doses (less than 1 mL) can be administered with a tuberculin syringe (without a needle).


MEDICATION CUPS & DROPPERS Manufacturers often provide a medication

cup for OTC liquids. These are plastic cups that contain specific

dose demarcations in different units of measure.

Droppers offer the ability to deliver the correct dosage of smaller volumes of medication.

Dropper – contains a small squeezable bulb at one end and a hollow glass or plastic tube with a tapering point.

Viscosity – the thickness and flow characteristics of fluids.


TRANSMUCOSAL ROUTE OF ADMINISTRATION Transmucosal route of administration –

allows the drug to be absorbed through or across the “sieve-like” or permeable mucous membranes of the mouth, eyes, ears, nose, rectum, vagina and urethra.

What advantages are there to using a transmucosal route of administration?

Transmucosal dosage forms include: tablets, gum, and lozenges (sublingual); ointments, solutions, suspensions, and sprays (eyes, ears, and nose); suppositories and solutions (rectum, urethra, and vagina).


SUBLINGUAL MEDICATIONS Sublingual route of administration –

sub meaning “under” and lingua meaning “tongue”; the tablet is placed under the tongue, where it is rapidly absorbed by blood vessels.


BUCCAL MEDICATIONS Buccal route of administration – a

drug absorbed by the blood vessels in the lining of the mouth.

What are some examples of drugs administered via this route?

Lozenge – troche, solid dosage form containing active ingredients and flavorings, that are dissolved in the mouth.


OPHTHALMICS, OTICS, AND NASAL SPRAYS/SOLUTIONS All can be delivered to a specific site with

a minimum of systemic side effects. Irrigating solution – a solution for

cleansing or bathing an area of the body, can be used both topically as well as instilled.

OphthalmicsOcular route of administration –

application of a drug into the eye.Conjunctival route of administration –

the application of a drug to the conjunctival mucosa.


OPHTHALMICS, OTICS, AND NASAL SPRAYS/SOLUTIONS Otics

Otic route of administration – the application of a drug into the ear canal.

Eardrops can never be used in the eye, but eyedrops can be used in the ear.

Nasal sprays/solutions Intranasal route of administration – the

application of a drug into the passages of the nasal cavity.

Spray – a dosage form that consists of a container having a valve assembly unit, when activated, emits a fine dispersion of liquid.


SUPPOSITORIES AND SOLUTIONS Suppository – an example of a

semisolid dosage form that is created from an inactive ingredient and formulated to melt at body temperature and release an active drug.


SUPPOSITORIES AND SOLUTIONS Rectal suppositories/solutions

Rectal route of administration – used to deliver drugs into the rectum.

Enema – a water-based solution administered rectally for cleansing or evacuating the bowel before a GI procedure.

Vaginal suppositories/solutionsVaginal route of administration – the

application of any drug within the vagina. Urethral suppositories/solutions

Urethral route of administration – the application of a drug within the urethra.


ADVANTAGES AND DISADVANTAGES OF CERTAIN TRANSMUCOSAL DOSAGE FORMS Sublingual medications

Advantage: rapid onsetDisadvantage: short duration

Buccal medicationsAdvantage: faster onsetDisadvantage: “dose dumping”

Ophthalmics, otics, and nasal sprays/solutionsAdvantage: fast onsetDisadvantage:


ADVANTAGES AND DISADVANTAGES OF CERTAIN TRANSMUCOSAL DOSAGE FORMS Suppositories and Solutions Rectal suppositories/solutions

Advantage: used in both old and youngDisadvantage: patient inconvenience

Vaginal suppositories/solutionsAdvantage: self-treatmentDisadvantage:


DISPENSING AND ADMINISTRATION OF TRANSMUCOSAL DOSAGE FORMS

Sublingual medications – storage requirements; nitroglycerin.

Buccal medications – chewing differences between regular gum and nicotine gum

Ophthalmics, otics, and nasal sprays/solutionsOphthalmics – administered at or near room

temperature; Fig. 4.2Otic – store at room temperature; Fig. 4.3Nasal medications – used for relief of nasal

congestion or prevention of allergy symptoms


DISPENSING AND ADMINISTRATION OF TRANSMUCOSAL DOSAGE FORMS

Suppositories and solutions – certain preparatory steps and administrative techniquesRectal medications – proper storage and

administrationVaginal medications – use medication for

prescribed time period; Table 4.4 Proper Technique for Administration of Vaginal Medications, pg. 126


TOPICAL ROUTE OF ADMINISTRATION Topical route of administration –

application of a drug directly to the surface of the skin; exert local effects; side effects are minimal.

Ointments, pastes, and plastersOintment – a dosage form that is a water-in-oil

(W/O) emulsion – a formulation that contains a small amount of water dispersed in oil.

Liniment – a medicated topical preparationPaste – like an ointment that contains more solid

materials, creating a dense consistency.Plaster – a solid or semisolid that adheres to the

body and contains backing material such as paper, cotton, linen, silk, moleskin, or plastic.


TOPICAL ROUTE OF ADMINISTRATION Creams, lotions, and gels

Cream – an oil-in-water (O/W) emulsion – a small amount of oil dispersed in water.

Lotion – another O/W emulsion for topical application. Gel – contains solid particles in a liquid, but the

particles are fine or ultrafine. Jelly – a gel that contains a higher portion of water in

combination with a drub substance and a thickening agent.

Glycerogelatin – a topical preparation made with gelatin, glycerin, water, and medicinal substances.

Colloid – a mixture with physical properties that fall between a solution and a fine suspension.

Irrigating solutions – douche, is often reconstituted from a powder and introduced into the vaginal cavity for local cleansing.


ADVANTAGES AND DISADVANTAGES OF CERTAIN TOPICAL DOSAGE FORMS

Major advantage of topicals is they have a fast onset of action with relatively few systemic side effects.

OintmentsAdvantage: especially good for extremely

dry areas of skinDisadvantage: appearance and greasy

residue Creams, lotions and gels

Advantage: apply more smoothly to the skin and leave a very thin film

Disadvantage:


DISPENSING AND ADMINISTRATION OF TOPICAL DOSAGE FORMS

Ointments – risk of increased absorption; careful application of topical medications; nitroglycerin; corticosteroid ointments.

Creams, lotions, and gels – specific precautions that patients should follow during application.


INHALATION ROUTE OF ADMINISTRATION Inhalation route of administration –

the application of a drug through inhalation into the lungs, typically through the mouth.

Inhalation Dosage Forms: Aerosols and MDIs

Aerosol – a spray in a pressurized metered-dose container that contains a propellant

Metered-dose inhaler (MDI) – a handheld, propellant-driven device, an MDI provides a specific measured amount of medication with compressed gas.


INHALATION DOSAGE FORMS Sterile Solutions and Nebulizers

Nebulizer – atomizing machine that delivers medication as a mist

Volatile Medications and VaporizersUsed to deliver moisture to the air for relief

of cold systems Micronized Powders and Nonaerosolized

InhalersBreath-activated powder for inhalation to

avoid propellantsAdministers a higher concentration of drug

as a micronized powder into the lungs


ADVANTAGES AND DISADVANTAGES OF CERTAIN INHALATION DOSAGE FORMS

Major advantage of inhalation dosage forms is the rapid onset of action, which is only second to the IV route of administration.

Major disadvantage is poor inhalation technique, with all MDIs; higher risk of side effects with larger amounts of medication.


DISPENSING AND ADMINISTRATION OF INHALATION DOSAGE FORMS

The more immediate-acting drug when using multiple MDIs should be used first, followed by the second 5-10 minutes later.

Table 4.5 Proper Technique for Administration of an MDI, pg. 132

Spacer device – the medication is released into a “storage chamber” where it can be more easily inhaled by the patient.

The patient should be sure to rinse their mouth after administration of an MDI to prevent an oral fungal infection.


PARENTERAL ROUTE OF ADMINISTRATION Parenteral solution – a sterile or microbial-

free solution (w/ or w/o medication) that is administered via a hollow needle or catheter inserted through one or more layers of skin.

Parenteral comes from the Greek roots para meaning “beside” and enteron meaning “intestine.”

This route bypasses – or goes “beside” rather than through – the alimentary canal or GI tract.

Parenteral route of administration – the injection of any drug or fluid into the bloodstream, muscle, or skin.


PARENTERAL DOSAGE FORMS IV Route – one of the more common

parenteral routes of drug and fluid administration. Intravenous (IV) infusion – a method for

delivering a large amount of fluid and/or high concentration of medication directly into the bloodstream over a prolonged period and at a slow, steady rate.

IM Route – used to administer antibiotics, narcotics, medications for migraine headaches…and vaccines. Injection – administration of a parenteral

medication into the bloodstream, muscle or skin


PARENTERAL DOSAGE FORMS Subcutaneous route – administer

medications below the skin into the subcutaneous tissue.

What are some common medications administered subcutaneously?

ID route – used for diagnostic and allergy skin testing, local anesthesia, and various diagnostic tests and immunizations.

What ID administrations mentioned in your text?


ADVANTAGES AND DISADVANTAGES OF CERTAIN PARENTERAL DOSAGE FORMS

The parenteral route is used for medications that contain molecules that are unstable, to large for absorption, or broken down to quickly in the stomach or liver.

IV route – preferred route of administration in an emergency situation; rapid action to control and treat symptoms.

IV bolus injection – administration of a drug all at once.

IV infusion – continuous amount of needed medication over a given period.


ADVANTAGES AND DISADVANTAGES OF CERTAIN PARENTERAL DOSAGE FORMS

Pyrogens – fever-producing by-products of microbial metabolism.

Embolism – blockage of a vessel. Phlebitis – a severe painful reaction at

the injection site. IM route – offers a more convenient way

to deliver injectable medications; slower onset than IV administration; duration of action is much longer, making it more practical for use outside of a hospital setting; unpredictable rate of absorption.


DISPENSING AND ADMINISTRATION OF PARENTERAL DOSAGE FORMS

Parenteral preparations contain ingredients that are dissolved or reconstituted with solutions.

Most parenteral preparations are made up of ingredients place in a sterile water medium.

Administration of IV, IM, subcutaneous or ID must be sterile because they introduce medication directly into the body.

Only trained professionals and healthcare providers are legally allowed to give parenteral injections.


DISPENSING AND ADMINISTRATION OF PARENTERAL DOSAGE FORMS Parenteral injections are administered via a

syringe and/or needle. Syringe – a calibrated device used to

accurately draw up, measure, and deliver medication to a patient through a needle.

Common syringes Insulin syringe Tuberculin syringe

Cannula – bore area inside the syringe Hypodermic syringe

Needle – attached to the tip of a syringe and is used to either draw fluid into or push fluid out of the syringe; the larger the gauge the smaller the opening.


DISPENSING AND ADMINISTRATION OF PARENTERAL DOSAGE FORMS

IV Route – IV medications can be administered via two routes: IV bolus and IV infusions.

Patient-controlled analgesia (PCA) infusion device – a programmable machine that delivers a small amount of painkillers upon patient demand.


DISPENSING AND ADMINISTRATION OF PARENTERAL DOSAGE FORMS IM Route – IM injection doesn’t work as fast

as an IV injection

infusion, but the

pharmacological effect

will last longer.

Subcutaneous Route –

injections

typically

administered on the

outside of the upper arm, top of the

thigh, or lower portion of each

side of the abdomen.


DISPENSING AND ADMINISTRATION OF PARENTERAL DOSAGE FORMS Administration of Insulin – most commonly

used medication that is administered subcutaneously is insulin.

Insulin Product Selection – syringe size, needle length and needle gauge. Insulin vials are 10mL (containing 1,000 units of insulin); prefilled syringes contain 3mL.

Insulin vials – Syringes sizes 0.3mL, 0.5mL, 1mL; size is determined by dose of insulin; insulin vials should never be shaken.

Insulin Pens – a portable device in which the prescribed dose of medication is “dialed up” to administer insulin.


DISPENSING AND ADMINISTRATION OF PARENTERAL DOSAGE FORMS What are some of the advantages of the

insulin pens? Disadvantages? Storage of insulin – insulin must be protected

against extreme temperatures. Open vials and pens can be stored at room temperature and discarded after one month. Unopened vials and pens should remain refrigerated.

Insulin Coverage for Insulin Supplies – insurance companies require a prescription for coverage of diabetic supplies.

ID Route – ID injections are given into the capillary-rich skin layer just below the epidermis.


DRUG DELIVERY SYSTEMS Drug delivery system – a design feature of

a dosage form that modifies the release of a drug by one or more pharmacokinetic parameters of the drug.

Improved efficacy and safety is a result of formulating medications based on the pharmacokinetic process.

Tablets or capsules have coatings to delay release and protect the stomach or extend their release.

Transdermal patches release medication slowly over a certain period of time.

Vaginal rings and intrauterine devices are inserted vaginally to prevent pregnancy.


DELAYED-RELEASE AND EXTENDED-RELEASE TABLETS AND CAPSULES

Most tablets and capsules are “immediate-release,” the medication is designed to activated or released shortly after the drug is taken.

Alphabet of release formulations: DR, CR, CD, XR, SR, XT, and XL.

Delayed-release (DR) formulations – have a special coating designed to delay absorption of the medication and to resist breakdown by acidic gastric fluids.Enteric-coated tablet (ECT) – delay-

release formulation.


DELAYED-RELEASE AND EXTENDED-RELEASE TABLETS AND CAPSULES

Extended-release (XL) formulations – allow a reduced frequency of dosing as compared with immediate-release medications.Sustained-release (SR) formulations:

two doses every 8-12 hours. Controlled-release (CR) formulations:

one dose


WAX MATRIX, OSMOTIC PRESSURE, AND TARGETED RELEASE SYSTEMS New drug delivery systems employ scientific

and biotechnologic processes to design medications to produce long-term effects.

Matrix-controlled release formulations – a reservoir-controlled release utilizing an osmotic pressure principle or an ion exchange resin. OxyContin (matrix-controlled release) Tussionex (ion exchange resin)

Wax matrix systems – the drug is embedded in a polymer matrix, release takes place by partitioning of the drug into the polymer matrix and surrounding medium.


WAX MATRIX, OSMOTIC PRESSURE, AND TARGETED RELEASE SYSTEMS Osmotic pressure system – the drug

is delivered to the body by slowly being “pushed out” into the bloodstream.

Target drug delivery systems – a drug is “carried” by a liposome, and released at a targeted organ site; increasing availability in the near future.


TRANSDERMAL PATCHES Transdermal dosage form – designed

to deliver a drug contained within a patch or disk to the bloodstream via absorption through the skin.

Therapeutic uses – effects last 24 hours to 1 week.

Administration – transdermal patches should be applied to a relatively hair-free area; localized heat speeds up the movement from the patch into the body.


MISCELLANEOUS DELIVERY SYSTEMS Vaginal ring delivery system and

intrauterine device continually deliver hormones to a female’s reproductive tract.

NuvaRing

Intrauterine device (IUD) – another way to prevent conception via a drug delivery device.


This workforce solution was funded by a grant awarded by the U.S. Department of Labor’s Employment and Training Administration. The solution was created by the grantee and does not necessarily reflect the official position of the U.S. Department of Labor. The Department of Labor makes not guarantees, warranties, or assurances of any kind, express or implied, with respect to such information, including any information on linked sites and including, but not limited to, accuracy of the information or tis completeness, timeliness, usefulness, adequacy, continued availability, or ownership.

This work by Mineral Area College is licensed under the Creative Commons Attribution 4.0 International License.

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RESOURCES Picture on slide 15

Capsule by Pixabay is licensed under CC BY Picture on slide 24

Female lips by Pixabay is licensed under CC BY Picture on slide 29

Human head anatomy with external and internal carotid arteries by Patrick J. Lynch licensed under CC BY

Picture on slide 33 Suppository by Eric Schulz licensed under CC BY

Picture on slide 64 Vaginal ring by Victor byckttor licensed under

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Routes of Drug Administration and Dosage Formulations Created by Jennifer Majeske, Mineral Area...

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