Dosage Forms and Routes of Administration

Home , Dosage form, Inhalation, Inhaler, Intrauterine device, Liniment, Nebulizer

Chapter 4

• A dosage form is the physical manifestation of a drug: – Solid – Liquid – Gas • Drug delivery system affects how the drug is released in the body.

drug delivery system a design feature of the dosage form that affects the delivery of the drug; may protect the stomach or delay the release of the active drug

Safety Note Although tablets and capsules may have distinctive markings and colors, the pharmacy technician should rely on the drug label and the NDC (National Drug Code) number, not the look of the medication, when confirming the identity of a drug.

• Tablets • Capsules • Lozenges, Troches, or Pastilles • Powders and Granules

• Available in a variety of sizes and shapes • Produced by compression • Contain one or more active ingredients plus inactive ingredients (see Table 4.1)

Multiple compression tablet (MCT) is either a – Tablet on top of another tablet, or – Tablet within a tablet – Core and shells or layers each contain different medicine

© Paradigm Publishing, Inc. 8 Terms to Remember tablet the solid dosage form produced by compression and containing one or more active and inactive ingredients multiple compression tablet (MCT) a tablet formulation on top of a tablet or a tablet within a tablet, produced by multiple compressions in manufacturing

• Caplet just tablet shaped like capsule • Solid interior, unlike capsule • Advantages – Easier to swallow than large tablet – Longer shelf-life than capsule – More tamper-proof than capsule

• Chewable tablets contain a flavored and/or colored base: – Antacids – Antiflatulents – Vitamins – Children’s tablets • Oral disintegrating tablets (ODT) melt in the mouth; preferred for those who have difficulty swallowing

© Paradigm Publishing, Inc. 12 Terms to Remember chewable tablet a solid oral dosage form meant to be chewed; readily absorbed; commonly prescribed for school-age children oral disintegrating tablet (ODT) a solid oral dosage form designed to dissolve quickly on the tongue for oral absorption and ease of administration without water Tablets

Coatings can be used to improve – Appearance – Flavor – Ease of swallowing

Common tablet coatings – Sugar-coated tablet (SCT): improves taste and appearance; harder to swallow – Film-coated tablet (FCT): improves appearance; can lessen side effects – Enteric-coated tablet (ECT): designed to bypass stomach and be absorbed in small intestine

© Paradigm Publishing, Inc. 16 Terms to Remember film-coated tablet (FCT) a tablet coated with a thin outer layer that prevents serious GI side effects enteric-coated tablet (ECT) a tablet coated in a way designed to resist destruction by the acidic pH of the gastric fluids and to delay the release of the active ingredient

Safety Note

ECT or delayed-release tablets should not be split.

• Consist of a gelatin shell that encloses the drug • Contain powders, granules, or liquids • May also contain – Inert filler (diluent) – Disintegrants – Solubilizers – Preservatives

© Paradigm Publishing, Inc. 19 Terms to Remember capsule the dosage form containing powder, liquid, or granules in a gelatin covering diluent an inactive ingredient that allows for the appropriate concentration of the medication in the tablet or capsule; also used to reconstitute parenteral products

• Most tablets and capsules are immediate-release. • Some are not immediate-release: – Controlled-release: intended to regulate the rate at which a drug is released – Sustained-release (SR): dosing reduced from immediate-release – Extended-release : dosing reduced from immediate-release and most sustained- release forms

© Paradigm Publishing, Inc. 22 Terms to Remember sustained-release (SR) dosage form a delayed-release dosage form that allows less frequent dosing than an immediate-release dosage form extended-release (XL) dosage form a tablet or capsule designed to reduce frequency of dosing compared with immediate-release and most sustained- release forms Capsules

Safety Note

Watch drug labels very carefully! A sustained-release (SR) dosage form is not the same as an extended- release (XL) dosage form of the same drug.

© Paradigm Publishing, Inc. 24 Lozenges, Troches, or Pastilles • Contain active ingredients and flavorings that are dissolved in the mouth • Usually have a local therapeutic effect • Examples include – OTC lozenges for sore throat – Prescription drugs such as nystatin or clotrimazole – Some narcotic medications

• Powders are milled and pulverized by machines. • Examples include – Bacitracin zinc – Antacids – Brewer’s yeast – Laxatives

• Granules are larger than powders. • Granules are formed by adding small amounts of water to powders. • Granules can be compressed into tablets or enclosed in capsules. • Granules generally have – An irregular shape – Excellent flow characteristics – Greater stability than powders

• Effervescent salts are coarse powders or granules containing both – Medicinal agent(s) – Sodium bicarbonate with an acid • When dissolved in water, effervescent salts release carbon dioxide gas, causing distinctive bubbling.

powders fine particles of medication used in tablets and capsules

© Paradigm Publishing, Inc. 30 Terms to Remember granules a dosage form larger than powders that is formed by adding very small amounts of liquid to powders effervescent salts granular salts that release gas and dispense active ingredients into solution when placed in water Semisolid Dosage Forms

• An emulsion is a mixture of two unblendable substances. • An oil-in-water emulsion contains a small amount of oil dispersed in water as a cream or lotion. • A water-in-oil emulsion contains a small amount of water dispersed in oil as an ointment.

emulsion the dispersion of a liquid in another liquid varying in viscosity

© Paradigm Publishing, Inc. 33 Terms to Remember oil-in-water (O/W) emulsion an emulsion containing a small amount of oil dispersed in water, as in a cream water-in-oil (W/O) emulsion an emulsion containing a small amount of water dispersed in an oil, such as an ointment Semisolid Dosage Forms

• Ointments • Creams • Gels • Suppositories

• Can be medicated or nonmedicated • May contain various bases – Oleaginous, such as mineral oil or petroleum jelly – W/O emulsions such as lanolin or cold cream – O/W emulsions such as hydrophilic ointment – Water-soluble bases such as polyethylene glycol

• A paste is like an ointment but with more solids, such as zinc oxide paste. • A plaster is a preparation that adheres to the body and contains a backing material.

liniment a medicated topical preparation for application to the skin, such as Ben Gay

© Paradigm Publishing, Inc. 39 Terms to Remember paste a water-in-oil (W/O) emulsion containing more solid material than an ointment plaster a solid or semisolid, medicated or nonmedicated preparation that adheres to the skin Creams

• Creams are a O/W emulsion and are usually invisible once applied. • Lotions are topical O/W emulsions that are easily absorbed: – Calamine lotion (to relieve itching) – Benzoyl peroxide (for acne)

© Paradigm Publishing, Inc. 41 Terms to Remember cream a cosmetically acceptable oil-in-water (O/W) emulsion for topical use on the skin lotion a liquid for topical application that contains insoluble dispersed solids or immiscible liquids

• A gel contains solid particles in liquid. • A jelly is a type of gel that contains a higher proportion of water. • A glycerogelatin is a topical preparation made with gelatin, glycerin, water, and medicine.

© Paradigm Publishing, Inc. 44 Terms to Remember jelly a gel that contains a higher proportion of water in combination with a drug substance, as well as a thickening agent glycerogelatin a topical preparation made with gelatin, glycerin, water, and medicinal substances

Suppositories

• Have a base of cocoa butter or glycerin • Are designed to melt when inserted into a body orifice, such as the rectum or vagina

suppository a solid formulation containing a drug for rectal or vaginal administration

• Consist of one or more active ingredients in a liquid vehicle • Often less stable than solids • Allow easier dosage adjustments • Often used for children’s medication – can be flavored to improve compliance

• Solutions • Dispersions

• Active ingredients are completely dissolved in liquid vehicle: – Aqueous (water-based) – Alcoholic (alcohol-based) – Hydroalcoholic (water-and-alcohol- based) • Solute is the active ingredient. • Solvent is the liquid vehicle.

© Paradigm Publishing, Inc. 50 Terms to Remember solution a liquid dosage form in which the active ingredients are completely dissolved in a liquid vehicle solute an ingredient dissolved in a solution or dispersed in a suspension solvent the vehicle that makes up the greater part of a solution

• Aromatic water is a solution of water and oils that are easily released into the air (e.g., rose water). • An elixir is a clear, sweetened, flavored solution containing ethanol and an active ingredient (phenobarbital elixir). • A syrup is an aqueous solution thickened with sugar and often used to mask taste of pediatric medications.

© Paradigm Publishing, Inc. 52 Terms to Remember aromatic water a solution of water containing oils or other substances that have a pungent, and usually pleasing, smell and are easily released into the air

© Paradigm Publishing, Inc. 53 Terms to Remember elixir a clear, sweetened, flavored solution containing water and ethanol syrup an aqueous solution thickened with a large amount of sugar (generally sucrose) or a sugar substitute such as sorbitol or propylene glycol

Safety Note

Syrups should be used cautiously in diabetic patients because of high sugar content.

• An extract is a potent dosage derived from animal or plant sources, with most of the solvent having been evaporated. • A fluidextract is a liquid dosage extracted from plants and commonly used in syrups (such as vanilla). • A tincture is an alcoholic or hydroalcoholic solution of plant extractions (such as iodine).

© Paradigm Publishing, Inc. 56 Terms to Remember extract a potent dosage form derived from animal or plant sources from which most or all of the solvent has been evaporated to produce a powder, an ointment-like form, or a solid

© Paradigm Publishing, Inc. 57 Terms to Remember fluidextract a liquid dosage form prepared by extraction from plant sources and commonly used in the formulation of syrups tincture an alcoholic or hydroalcoholic solution of extractions from plants

Other solutions include – Spirits, such as camphor or peppermint spirit – Irrigation solutions, used to cleanse the ear, eye, or wounds and incisions

© Paradigm Publishing, Inc. 59 Terms to Remember spirit an alcoholic or hydroalcoholic solution containing volatile, aromatic ingredients irrigating solution any solution used for cleansing or bathing an area of the body, such as the eyes or ears

© Paradigm Publishing, Inc. 60 Solutions Solutions are sometimes classified by their site or method of administration: – Topical (local) – Systemic (throughout the body) – Epicutaneous (on the skin) – Percutaneous (through the skin) – Oral (by mouth) – Otic (by ear) – Ophthalmic (by eye) – Parenteral (by injection) – Rectal (by rectum) – Urethral (by urethra) – Vaginal (by vagina)

• In a dispersion, medication is distributed throughout the vehicle but is not totally dissolved. • A suspension is the dispersion of an undissolved solid in a liquid. • Suspensions are useful for those who may have difficulty swallowing solid forms.

Safety Note

The drug stock bottles of liquid suspensions and emulsions for oral use should always be shaken well by pharmacy technicians before being poured into smaller medication bottles.

• Colloids have properties between a solution and a fine suspension. Milk of magnesia and Aveeno (with colloidal oatmeal) are examples. • Microemulsion contains one liquid dispersed in another, such as Haley’s M-O and Compound W.

© Paradigm Publishing, Inc. 67 Terms to Remember magma a milklike liquid colloidal dispersion in which particles remain distinct, in a two- phase system (e.g., milk of magnesia) microemulsion a clear formulation that contains one liquid of extremely fine sized droplets dispersed in another liquid (e.g., Haley’s M-O) Inhalation Dosage Forms

• Inhalations are inhaled through the nose or mouth. • Dosages can be delivered via spray or aerosol. • Inhalations are often used to treat allergies and asthma.

© Paradigm Publishing, Inc. 69 Terms to Remember spray the dosage form that consists of a container with a valve assembly that, when activated, emits a fine dispersion of liquid, solid, or gaseous material aerosol a pressurized container with propellant used to administer a drug through oral inhalation into the lungs

• Delivers drug to the bloodstream by absorption through the skin • Transdermal patch consists of – Backing – Drug reservoir – Control membrane – Adhesive layer – Protective strip

• Absorption occurs slowly. • Effects last 24 hours to 1 week. • Used to deliver – Nicotine (smoking cessation) – Nitroglycerine (chest pain) – Narcotic analgesics (chronic pain) – Scopolamine (motion sickness)

© Paradigm Publishing, Inc. 72 Terms to Remember transdermal dosage form a formulation designed to deliver a continuous supply of drug into the bloodstream by absorption through the skin via a patch or disk

• Route of administration is a way to get a drug into or onto the body. • Routes can produce a systemic effect or a local effect.

© Paradigm Publishing, Inc. 74 Terms to Remember route of administration a way of getting a drug onto or into the body, such as orally, topically, or parenterally oral route of administration the administration of medication through swallowing for absorption along the GI tract into systemic circulation

Some routes produce a systemic effect: – Oral (by mouth) – Sublingual (under the tongue) – Buccal (between gum and cheek)

systemic effect the distribution of a drug throughout the body by absorption into the bloodstream

© Paradigm Publishing, Inc. 77 Terms to Remember sublingual route of administration oral administration in which a drug is placed under the tongue and is rapidly absorbed into the bloodstream buccal route of administration oral administration in which a drug is placed between the gum and the inner lining of the cheek; also called transmucosal route of administration

Other routes produce a local effect: – Topical (on the skin) – Intrarespiratory (inhaled into the lungs) – Ocular (to the eye) – Conjunctival (to the lining of the eyelid) – Otic (to the ear canal) – Nasal (to the nose) – Rectal (to the rectum) – Vaginal (to the vagina) – Urethral (to the urethra)

© Paradigm Publishing, Inc. 79 Terms to Remember topical route of administration the administration of a drug on the skin or any mucous membrane such as the eyes, nose, ears, lungs, vagina, urethra, or rectum; usually administered directly to the surface of the skin local effect the site-specific application of a drug

© Paradigm Publishing, Inc. 80 Terms to Remember intrarespiratory route of administration the administration of a drug by inhalation into the lungs; also called inhalation ocular route of administration the placement of ophthalmic medications into the eye

© Paradigm Publishing, Inc. 81 Terms to Remember conjunctival route of administration the placement of sterile ophthalmic medications in the conjunctival sac of the eye(s) otic route of administration the placement of solutions or suspensions into the ear

© Paradigm Publishing, Inc. 82 Terms to Remember nasal route of administration the placement of sprays or solutions into the nose rectal route of administration the delivery of medication via the rectum Terms to Remember vaginal route of administration the administration of a drug by application of a cream or insertion of a tablet into the vagina urethral route of administration the administration of a drug by insertion into the urethra

• Some medications must administered via the parenteral route because their molecules are too large or are broken down too quickly. • Drugs are distributed systemically by injection or catheter.

© Paradigm Publishing, Inc. 85 Terms to Remember parenteral route of administration the injection or infusion of fluids and/or medications into the body, bypassing the GI tract injection the administration of a parenteral medication into the bloodstream, muscle, or skin

• Advantages and Disadvantages of the Oral Route • Dispensing and Administering Oral Medications • Advantages and Disadvantages of the Topical Route • Dispensing and Administering Topical Medications • Advantages and Disadvantages of the Parenteral Route • Dispensing and Administering Parenteral Medications

Advantages – Convenient – Easy to tolerate – Safe – Simple to administer – Fractional doses can be taken by splitting scored tablets

Careful tablet splitting may reduce medication costs, but it is not recommended for all drugs.

© Paradigm Publishing, Inc. 89 Advantages and Disadvantages of the Oral Route Disadvantages – Delayed onset – Destruction of the drug by GI fluids – Delayed absorption due to food and drink in the stomach – For liquids, potential unpleasant taste – For controlled-release formulations, cannot be split or crushed

The oral route is not appropriate for patients who are experiencing nausea or vomiting.

© Paradigm Publishing, Inc. 91 Dispensing and Administering Oral Medications Pharmacists should tell patients – What foods to take or not take – What behaviors to avoid (sun, driving) – Methods for swallowing pills – How to store medications

Always check the manufacturers’ recommendations for storage and expiration dating of reconstituted products.

© Paradigm Publishing, Inc. 93 Dispensing and Administering Oral Medications Measuring utensils are often dispensed with the medications: – Spoons – Cups – Oral syringes (for pediatric meds) – Droppers (for infant meds)

© Paradigm Publishing, Inc. 94 Terms to Remember oral syringe a needleless device for administering medication to pediatric or older adult patients unable to swallow tablets or capsules dropper a measuring device used to accurately dose medication for infants

© Paradigm Publishing, Inc. 95 Advantages and Disadvantages of the Topical Route Generally, the topical route – Works quickly – Produces a therapeutic effect that is localized – Provides fast relief – Has fewer side effects than with a systemic medication

© Paradigm Publishing, Inc. 96 Advantages and Disadvantages of the Topical Route • Ointments – Good for extremely dry areas – Greasy feel • Transdermal – Steady level of drug, good compliance – Costly, occasional skin irritation

© Paradigm Publishing, Inc. 99 Terms to Remember diskus a nonaerosolized powder used for inhalation nebulizer a device used to deliver medication as a mist to the lungs; often used in treating asthma Advantages and Disadvantages of the Topical Route • Vaginal and urethral – Higher concentration of medication – Inconvenient and messy to use • Rectal – Bypasses digestive system, good for nauseous patients – Inconvenient to use, may cause discomfort

Ointments, creams, lotions, and gels – Might require use of gloves to avoid too much drug absorption (nitroglycerin gel) or to avoid irritation (capsaicin) – Might need to be applied sparingly to avoid side effects (corticosteroids)

Transdermal patches – Site must be relatively free of hair and scar tissue. – Rotate application site. – Follow patch replacement schedule.

© Paradigm Publishing, Inc. 103 Dispensing and Administering Topical Medications Ophthalmic medications – Should be at or near room or body temperature – Must be stored properly – Should be applied with clean hands – Should be applied with proper technique for dispensing drops or ointment into eye

© Paradigm Publishing, Inc. 104 Dispensing and Administering Topical Medications Otic medications – Should be at or near room or body temperature – Should be applied with proper technique to ensure medication reaches target

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

© Paradigm Publishing, Inc. 106 Dispensing and Administering Topical Medications Nasal medications – Nasal medications are applied by drops (instillation), sprays, or aerosols. – Proper technique is key to avoid sniffing medication into sinuses. – Patients must not overuse OTC nasal decongestants.

© Paradigm Publishing, Inc. 107 Dispensing and Administering Topical Medications Inhaled medications – Proper technique must be followed to ensure that medication reaches the lungs. – With cortisone MDIs, patient should rinse mouth after application to avoid fungal infections. – Spacer devices can be used with inhalers for children.

© Paradigm Publishing, Inc. 108 Dispensing and Administering Topical Medications Vaginal medications – The vaginal route is indicated for infections or hormone replacement. – Creams and ointments are often delivered via applicator tube. – For contraception, hormones can be delivered via a ring surrounding the cervix. – Intrauterine devices can deliver medication for contraception or cancer treatment.

© Paradigm Publishing, Inc. 110 Dispensing and Administering Topical Medications Rectal medications – Patients should be instructed to remove wrappers before using. – Patients should be instructed on proper orientation of suppository before insertion. – Proper technique should be followed when administering enemas.

Safety Note

Refrigeration is necessary to store most rectal medications.

© Paradigm Publishing, Inc. 112 Advantages and Disadvantages of the Parenteral Route Advantages – Can deliver high concentrations of medication at once or over long period of time – Can be administered to almost any organ or part of the body – Acts quickly

© Paradigm Publishing, Inc. 113 Advantages and Disadvantages of the Parenteral Route Disadvantages – Possible injury from needle insertion – Potential for introducing toxic agents into the body • Microbes • Pyrogens – Must be administered carefully to avoid introduction of air bubbles or particulates

© Paradigm Publishing, Inc. 114 Terms to Remember intravenous (IV) infusion the process of injecting fluid or medication into the veins, usually over a prolonged period of time pyrogen a fever-producing by-product of microbial metabolism

Safety Note

Do not use the abbreviations SQ or SC. Instead, write out subcutaneous to minimize potential medication errors.

• Parenteral medications consist of active ingredients dissolved in sterile water or saline. • Injections must be given by a trained healthcare professional.

© Paradigm Publishing, Inc. 118 Terms to Remember syringe a device used to inject a parenteral solution into the bloodstream, muscle, or under the skin cannula the barrel of a syringe or bore area inside the syringe that correlates with the volume of solution

Safety Note

Injections should be given by a trained healthcare professional, not by the pharmacy technician.

Intravenous injections or infusions – Can deliver a variety of medications or other substances – Usually administered in the superficial veins of the arm – Infusion pumps can deliver medication 24/7 or can be controlled by the patient

Safety Note

Only the patient should control the PCA pump button.

© Paradigm Publishing, Inc. 124 Dispensing and Administering Parenteral Medications Intramuscular injections – Can deliver a variety of medications or other substances – Volume limited to 2 to 3 mL – Injection site usually gluteus maximus (in adults) or deltoid (in children)

© Paradigm Publishing, Inc. 126 Dispensing and Administering Parenteral Medications Subcutaneous injections – Medications are administered below the skin to the subcutaneous tissue. – Insulin is the most common type of subcutaneous injection: • Insulin must be stored and prepared properly. • Patients must know proper method for injecting. – Subcutaneous injections are also used for epinephrine and heparin.

Safety Note

The patient should be instructed to agitate but not shake the insulin vial.

© Paradigm Publishing, Inc. 129 Dispensing and Administering Parenteral Medications Intradermal injections – Injected into the layer just below the epidermis – Used for • Local anesthesia • Immunizations • Diagnostic tests (tuberculosis, allergy testing)