6 Dosage Formulations and Routes of Administration

Sources of Drugs Natural drug sources Occur in nature and are naturally occuring Derived or extracted from plants, animals, and minerals

Sources of Drugs Natural drug sources Plant sources include: Acetylsalicyclic acid (aspirin) derived from white willow bark Cocaine derived from the coca plant Codeine and morphine derived from the opium poppy plant

Sources of Drugs Natural drug sources Animal sources include: Bovine insulin derived from cow pancreas Porcine insulin derived from pig pancreas Pepsin derived from cow stomach Thyroid hormones derived from pig thyroid gland

Sources of Drugs Natural drug sources Mineral sources include: Ferrous sulfate (iron) to treat iron deficiencies Gold used to treat arthritis Magnesium for milk of magnesia (laxative and antacid)

Sources of Drugs Natural drug sources Mineral sources include: Potassium to supplement low potassium levels Sodium chloride is common base solution for IV therapies Zinc for skin protectants and sunscreen

Sources of Drugs Synthetic drug sources Produced in a laboratory, not naturally occuring Semisynthetic: naturally occuring substance that has been chemically altered Synthesized: made in laboratory to imitate a naturally occurring drug

Sources of Drugs Synthetic drug sources Examples of synthetic drugs Adrenalin Synthesized epinephrine for treating hypersensitivity and asthma attacks Amoxicillin, ampicillin, and piperacillin Semi-synthetic pencillins to treat various infections

Sources of Drugs Synthetic drug sources Examples of synthetic drugs Barbiturates Synthetic CNS depressants OxyContin Synthetic opiate for pain management

Sources of Drugs Genetically engineered drug sources Recombinant DNA Combining two different DNA strands to produce a new strand of DNA or rDNA Human insulin created to treat diabetes Recombinant hepatitis B vaccine

Sources of Drugs Genetically engineered drug sources Monoclonal antibodies (MAbs) Hybrid cells created in laboratory from animals; used to treat tumors and diagnose various conditions Rituxan, Zevalin, Erbitux, Avastin: used in the treatment of various cancers

Drug Nomenclature Chemical name Reflects the chemical structure of the compound Often long and hard to remember and pronounce Named according to guidelines from the International Union of Pure and Applied Chemistry (IUPAC) Used primarily in research settings

Drug Nomenclature Generic name Convenient and concise Assigned by manufacturer in collaboration with the FDA Not capitalized May be used by anyone—not restricted by copyright or tradmark Used in the USP and the USP-NF

Drug Nomenclature Trade or brand name Registered or trademarked by a specific producer or manufacturer to identify its particular drug This name cannot be used by other manufacturers but a generic may be sold under more than one trade name. Usually capitalized Also called the "proprietary name"

Classification of Drugs Classifications based on: Chemical ingredients Method by which the drug is used Area of the body that is treated Two usual classification methods Therapeutic use Mechanism of action

Dosage Formulations Dosage forms How medication is prepared for administration to the patient Solid or liquid Single medication may be available in multiple dosage forms for use at various disease states, patient ages, and desired results.

Dosage Formulations Solid dosage forms Most widely available form Can be administered orally, rectally, vaginally, or topically Advantages and disadvantages

Dosage Formulations Solid dosage forms Tablets Small formed shapes usually taken by mouth Active and inert ingredients work together to ensure tablet is easy to swallow, taste, digestible, and releases drug at proper time.

Dosage Formulations Solid dosage forms Tablets Molded tablets made with mold and wet materials Compressed tablets formed by die-punching compressed, powdered, crystalline, or granular substances into a uniform shape, usually has a film, sugar coating, or enteric coating

Dosage Formulations Solid dosage forms Tablets Caplets are film-coated tablets in the shape of a capsule. Chewable tablets should be chewed for desired results. Effervescent tablets dissolve in liquid before administration. Fast dissolving tablets can be taken orally without water.

Dosage Formulations Solid dosage forms Tablets Sublingual tablets disintegrate and are absorbed under the tongue. Buccal tablets disintegrate in the buccal pouch, between the gums and the cheek. Vaginal tablets are dissolved and absorbed through the mucous lining of vagina.

Dosage Formulations Solid dosage forms Capsules have drug contained in a shell Soft gelatin shells are soft and elastic, flexible during administration, and can't be broken apart. Hard gelatin shells have two oblong halves joined together, which can be separated if necessary.

Dosage Formulations Solid dosage forms Lozenges (also called pastilles or troches) Hard, disk-shaped solid form in a sugar base Remains in the patient's mouth until has been completely dissolved and all medication releases

Dosage Formulations Solid dosage forms Powders Usually produced in large supplies for bulk compounding Can be used internally or externally Individual doses packaged in a powder paper

Dosage Formulations Solid dosage forms Granules Made from wetted then dried powders ground into course, nonuniform particles Commonly used in pediatric antibiotic suspensions Dissolved in distilled water

Dosage Formulations Solid dosage forms Medicated sticks For topical application of local anesthetics, sunscreens, antivirals, antibiotics, and cosmetics

Dosage Formulations Semisolid dosage forms Suppositories Administer medication via rectum, vagina, or urethral tract Melt or dissolve at body temperature Used for babies and other instances where oral dosing may not be practical Creams may or may not contain medication; oil-in-water or water-in-oil bases.

Dosage Formulations Semisolid dosage forms Ointments are applied externally to the skin or mucous membranes. Oleaginous ointments: emollients to soothe and cool. Hydrophobic, meaning not easy to wash off.

Dosage Formulations Semisolid dosage forms Ointments are applied externally to the skin or mucous membranes. Water-soluble ointments: contain no fat or water, easily wash off. Can be mixed with nonaqueous or solid medication Anydrous ointments: absorb water, turning into a water-in-oil emulsion

Dosage Formulations Semisolid dosage forms Ointments are applied externally to the skin or mucous membranes. Emulsions Emollient bases made of water-in-oil (occlusive) or oil-in-water (nonocclusive) Pastes Stiff or very viscous ointments that do not melt or soften at body temperature; usually contain at least 20% solids

Dosage Formulations Liquid dosage forms Solutions Medication is completely dissolved and evenly distributed (homogeneous) and quickly absorbed Aqueous solutions use purified/sterile water as vehicle for douches, irrigating solutions, enemas, washes, and sprays.

Dosage Formulations Liquid dosage forms Solutions Viscous aqueous solutions use purified/sterile water; thick, sticky—either liquid or semisolid; syrups, jellies, and mucilages.

Dosage Formulations Liquid dosage forms Solutions Nonaqueous solutions don't use water, usually alcohol, glycerin, or propylene glycol.

Dosage Formulations Liquid dosage forms Solutions Hydro-alcoholic solutions use alcohol and water as vehicle or dissolving agent. Example: Elixirs: liquid preparations with flavored water and alcohol mixtures for oral administration. Many drugs dissolve more easily this way. Range of alcohol contents varies from 2–30%.

Dosage Formulations Liquid dosage forms Solutions Hydro-alcoholic solutions use alcohol and water as vehicle or dissolving agent. Example: Aromatic elixirs are nonmedical, used to mask unpleasant medicine taste.

Dosage Formulations Liquid dosage forms Solutions Alcoholic solutions use no water, usually ethyl or ethanol alcohols. Collodions contain pyroxylin, applied to skin, can carry an added medication Spirits contain volatile and aromatic substances, administered internally or inhaled.

Dosage Formulations Liquid dosage forms Solutions Alcoholic solutions use no water, usually ethyl or ethanol alcohols. Glycerite contains medication dissolved in glycerin, then is mixed into a water or alcohol vehicle, often has viscous, jelly-like consistency, rarely used today.

Dosage Formulations Suspensions Contain very fine solid particles mixed with gas, liquid, or solid Break down faster than tablets or capsules Must be shaken well before use

Dosage Formulations Suspensions Usually intended for oral ingestion where large amount of medication is needed. Other routes Ophthalmic, parenteral, otic, and rectal

Dosage Formulations Suspensions Magmas and milks Lotions Suspensions of undissolved medications in water Lotions For external use only

Dosage Formulations Suspensions Gels Extractives Similar to magmas and milks but particles are smaller, used for oral or topical administration Extractives Drug extracted by soaking dried plant or animal tissue in solvent

Dosage Formulations Suspensions Tinctures Fluidextracts Extractive alcoholic and hydro-alcoholic solutions; each mL of tincture = 100 mg of crude ingredient Fluidextracts More potent than tinctures; each mL = 1,000 mg of crude drug

Dosage Formulations Suspensions Extracts Similar to tinctures and fluidextracts but potency of crude drug is 2–6 times stronger

Dosage Formulations Emulsions Mixtures of water and oil (which normally do not mix) Internal phase: one liquid broken into small elements External (or continuous) phase: the other liquid remains liquid Emulsifying agent added to keep two liquids from seperating

Dosage Formulations Liniments Applied to skin with friction and rubbing Can be solutions, suspensions, or emulsions Contain medication that mildly irritates skin, producing counterirritation or inflammation to relieve inflammation of deeper tissues or muscles Ben-Gay most common OTC liniment today

Dosage Formulations Transdermal patches Sprays Medicated adhesives that deliver medication directly into bloodstream through the skin Prescription and OTC applications Sprays Pump-type dispenser delivers medication nasally or translingually for quick absorption and onset

Dosage Formulations Inhalants Fine powder or solution delivered as mist into nose or mouth, immediately entering respiratory tract Asthma inhalers and allergy nasal sprays

Dosage Formulations Aerosols Very fine liquid or solid particles mixed in vehicle, packed with gas and pressure, administered via respiratory tract or topically

Delayed and Extended Releases Medications released over a period of time Extended release (ER) Long acting (LA) Sustained release (SR) Time release (TR) Controlled release (CR)

Routes of Administration Method by which medication is introduced into the body for absorption and distribution Varies from patient to patient Factors include patient's age, consciousness, medical condition, time to achieve results, and side effects.

Routes of Administration Oral Abbreviation: PO (per os, Latin for "by mouth") Advantages Safe, convenient, easy to store; readily available; lower cost, immediate release or extended release; easy to self-administer

Routes of Administration Oral Disadvantages Hard to swallow for those who are children, elderly, unconscious, ventilated, or having digestion problems Take longer to absorb and distribute

Routes of Administration Oral Sublingual Tablets administered under the tongue, bypassing the digestive system and diffusing directly into the blood supply Buccal Tablets and lozenges/troches administered between the gum and cheek, absorbed into bloodstream through mucous membranes

Routes of Administration Transdermal (percutaneous) Generally uses patch applied to skin Delivers medication to bloodstream Two kinds of patches One controls rate of delivery to skin and bloodstream One lets skin control rate of delivery

Routes of Administration Inhalation Medication inhaled through mouth directly into lungs Effective for lung conditions when immediate relief is needed Nasal Inhaled through nose and absorbed into the bloodstream Sprayed into nose for local effects

Routes of Administration Parenteral Medication does not pass through the gastrointestinal system. Quicker absorption and distribution Convenient for those who cannot take medicine orally Varied rate of delivery Dosage must be correct because action is immediate and unreversable.

Routes of Administration Parenteral Intradermal (ID) Injection into top layers of skin Subcutaneous (SC) Injection into tissue under the skin

Routes of Administration Parenteral Intramuscular (IM) Injection into large muscle masses, such as upper arm, thigh, buttock Intravenous (IV) Medication administered directly into vein

Routes of Administration Parenteral Other parenteral routes include: Implant Device inserted into the body to slowly release medication Intra-arterial Injection into artery Intra-articular Injection within joint

Routes of Administration Parenteral Other parenteral routes include: Intracardiac Injection into heart Intraperitoneal Injection into abdominal or peritoneal cavity Intrapleural Injection into sac (pleura) surrounding lungs

Routes of Administration Parenteral Other parenteral routes include: Intrathecal Injection into cerebrospinal fluid around spinal cord Intraventricular Injecting antibiotics or chemotherapy agents into brain cavities (ventricles)

Routes of Administration Parenteral Other parenteral routes include: Intravesicular Injection into urinary bladder Intravitreal Injection into vitreous body of the eye

Routes of Administration Topical Administered externally to the skin Absorbed into the mucous membrane, preventing particles from being absorbed into the bloodstream Rectal Administered through the rectum for local or systemic effects

Routes of Administration Vaginal Medications inserted into vagina for absorption and distribution for local or systemic conditions Ophthalmic Solutions, ointments, suspensions, or gels administered through the eye Treats conditions of the eye directly

Routes of Administration Otic Medications administered in the ear to treat infections, inflammation, and severe wax buildup Solutions and suspensions absorbed in the ear canal for immediate relief

Summary Drug sources, nomenclature, common dosage forms, routes of administration

Summary Important to: Dispense proper dosage form of medication Dispense proper dosage amount, especially for parenteral ROAs Pharmacy technician must understand drug names, the meaning and use of each dosage form and ROA.