Pharmaceutical Dosage Form

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Block C4 - Adolescence and Adulthood



Pharmacology
Office:3rd floor, Radiopoetro
Lab:3rd floor, Radiopoetro
Work-plan:On provided sheet.
Pre-test:10 MC.
Post-test:None.
Lab Report:On provided sheet.


Terms[edit]

Routes of Administration[edit]

An example of enteric-coated capsules

The route of administration refers to the way that a drug is introduced into the body. Parenteral is any route of administration which is not enteral (via the GIT) or taken topically or via inhalation. So, injections fall under the parenteral category of routes. Routes of administration can also be classified by whether they have a systemic (i.e. all over the body) or a local effect.

  • Systemic effect: oral, sublingual, buccal, rectal, parenteral, transdermal, and inhaled.
  • Local effect:
    • Topical: onto skin or mucosa, into eye, nose, ear, oral cavity, vagina, rectum, and bronchi.
    • Local parenteral: local anesthetic.
    • Oral: local effect within the GIT: antacid.

Dosage Form[edit]

The dosage form refers to the physical characteristics of a drug product. The dosage form (e.g. lotion) depends on the route of administration (e.g. topical) indicated. One way to categorize dosage forms is by their state:

  • Gaseous: vaporized administration by inhalation.
  • Solid: powder, tablet, capsule, transdermal patches.
  • Liquid: solutions, emulsions, suspensions.
  • Semisolid: cream, gel, ointment.

Dosage Forms[edit]

Topical Route
Dosage Form Characteristics Suitability/Advantages Disadvantages

Lotion

Cetaphillotion.png
  • Application to skin without rubbing.
  • Cools skin by evaporation of solvents, leaving thin coat.
  • Dries on the skin soon after application. Most lotions are aqueous or hydroalcoholic; small amounts of alcohol are added to aid solubilization of the active ingredient(s) and to speed up evaporation of the solvent from the skin.
  • Less oily than creams. Usually around 70-80% water.
  • Suitable for hairy area (e.g. hair on the head, for dandruff treatment) and lesions with minor exudate.
  • Suitable for sensitive, oily, dry, or facial skin (e.g. areas prone to acne or folliculitis).
  • Suitable for folded skin areas (e.g. groin, creases of the neck, and armpit).

Less potent than creams and ointments as they are not as occlusive for long periods.

Cream
Musclecream.png
  • Viscous liquid or semisolid emulsion of either water-in-oil or oil-in-water.
    • Oil-in-water (o/w) creams are more comfortable and cosmetically acceptable.
    • Water-in-oil (w/o) creams are moisturizing.
  • Usually 50% water and 50% oil.
  • Easily water washable. Easy to wipe away.
  • Less greasy compared to ointment.
  • Easy to spread on the skin's surface (i.e. easy to apply).
  • Suitable for sensitive, dry, and fair skin.
  • Suitable for acute lesions.
  • Stability is not as good as ointment.
Ointment
Article-2630794-1DEC87C900000578-917 634x389.jpg
  • Contains emollients (moisturizers) for skin hydration and to form a protective barrier.
  • Ointments have a higher concentration of oil (80%), compared to creams and lotions. Not unusual if 0% water.
  • Also known as "balm", "salve", and "unguent".
  • Occlusive. Prevents the escape of moisture.
  • Retained on the skin for prolonged periods.
  • Suitable for hyperkeratotic lesions, scaling, and eczematous lesions.
  • Very greasy.
  • Stains.
  • Difficult to wash off.
  • Contraindicated in exudative lesions.
Gel/Jelly
Diclofeniacgeltube.png
  • Transparent preparations containing cellulose ethers or carbomer in water or a water-alcohol mixture.
  • Based on aqueous polyethylene glycol.
  • Miscible with water.
  • Gels liquify on contact with the skin, dry and leave a thin film of active medication.
  • Much less greasy compared to ointment.
  • Gives cooling sensation.
  • Suitable for oily or dark skin.
  • Sticky.
Powder
Zeabsorbpowder.png
  • Mixture of finely divided drugs in dry form.
  • Suitable for obese patients, especially those with excessive sweating.
  • Suitable for folded skin areas (e.g. neck, belly, groin, and armpit).
  • Prevents reinfection.
Paste
Topicalpaste.png
  • Mixture of powder and ointment.
  • Contains a high proportion of finely powdered solids such as starch, zinc oxide, calcium carbonate, and talc.
  • Less greasy than ointments. Pastes are indicated for ulcerated lesions.
  • Less occlusive than ointments (can be a benefit depending on indication)
Transdermal patch
Wpc aug 2012 6b transdermal patch.jpg
  • Supports passage of drug through skin into systemic circulation.
  • Slow, controlled release of drug over time.
  • Suitable for patients that cannot tolerate oral dosage forms, nauseated, or unconscious.
  • Easy to terminate drug effect rapidly.
  • Good compliance.
  • Easy to identify the medication in emergency situations.
  • Local irritation. Local edema, erythema, or itching can be caused by the active ingredient, the adhesive, or other substances in the patch.
Oral Route
Dosage Form Characteristics Suitability/Advantages Disadvantages
Solution
461 1.png
  • Clear in appearance.
  • Prepared by dissolving one or more solutes in solvent.
  • Rapid absorption.
  • Suitable for children, adults, and geriatrics.
  • Requires administration of large volume.
Emulsion
Fishliveroilemulsion.png
  • Consists of two immiscible liquids.
  • Oil in water or water in oil.
  • Cloudy appearance. Shake before using.
  • Sometimes with sweetener.
Suspension
Tylenolinfants.png
  • Consists of solid particles that are dispersed in liquid.
  • Consists suspensator/stabilizer.
  • Absorption depends on particle diameter.
  • Cloudy appearance. Shake before using.
  • Suitable for children, adults, and geriatrics.
Compressed Tablets
Numark-500mg-paracetamol-tablets-.jpg
  • Oval or flat and round.
  • Contains one or more dry medicinal substances, and also pharmacutical adjuncts such as colorant and flavoring.
  • Simple and convenient to use.
  • Easily absorbed compared to tablets.
  • Difficult to swallow by children and the elderly.
Hard Capsule
Kapseln.JPG
  • Contains one or more dry medical substances.
  • Dissolves in gastric juices.
  • Used to mask the taste and odor of the active ingredient.
  • The capsule itself is tasteless.
  • Highly moisture sensitive.
  • Difficult to swallow by children and the elderly.
Slow-Release Tablets
Melatonintimerelease.png
  • Also known as retard and extended release tablets.
  • Dissolves slowly and releases drug over time.
  • Suitable for sustaining drug levels in the blood.
  • Requires less frequent drug administration. Improved patient compliance.
  • Risk of overdosing.
  • Should not be broken, crushed, or chewed. These tablets contain a high drug load and must be absorbed slowly.
  • Expensive.
Inhalation
Salbutamolinhaler.png
  • Also known as aerosol inhalation (pressurized dosage form) or metered dose inhalers.
  • Administered by nasal or oral respiratory route.
  • Local action or bronchial tree.
  • Rapid action.
  • No first-pass metabolism.
  • Ability to precisely target diseased area.
  • Inaccurate in dosage intake.
  • Difficult to handle.
  • Expensive.
Sublingual tablets
Nitroglycerintabletssublingual.png
  • Generally flat, oval tablets, that easily melt in the mouth, dissolve rapidly, with little or no residue.
  • Dissolve in oral mucosa beneath the tongue and enter venous flow via capillaries.
  • Rapid drug effect.
  • Bypass first-pass metabolism by the liver.
  • Indicated for drugs that, if swallowed, may be destroyed by gastric juice or poorly absorbed in stomach and intestine.
  • Tooth discoloration or decay caused by long-term use with acidic or caustic drugs and fillers.
  • Drug may not work as intended if accidentally chewed or swallowed.
Syrup
Cough syrup.jpg
  • Concentrated but contains sugar or sugar substitute.
  • Suitable for children.
  • Pleasant taste.
  • Faster acting than solid dosage form.
  • Inaccuracy in dosage intake.
  • More expensive than tablet.
Oral Drops
Amoxoraldrops.png
  • Also known as guttae oral.
  • Suitable for babies.
  • Requires administration of small volume.
  • Often with sweetener or flavoring.
Gargling liquid
Betadinekumurgargle.png
  • Aqueous (water or alcohol/water based) solutions used to prevent or treat throat infections.
  • Local effect.
  • Usually contains antiseptic for treating the throat.
Mouthwash
Listerinewash.png
  • Mouthwashes are aqueous solutions with a pleasant taste and odour used to clean and deodorize the mouth.
  • Usually contains local antiseptic.
  • Used for freshening and cleansing the oral cavity.
Lozenge
Strepsilslozenges.png
  • Disk-shaped solid dosage form.
  • Contains local anesthetic, local antiseptic, antibacterial, flavoring, and sweetener.
  • Used for minor mouth or throat pain (e.g. sore throat).
  • Practical and easy to obtain and use.
Sugar-coated Tablet
Sugarcoatedtablet.png
  • Compressed tablet coated with a colored or uncolored sugar.
  • The coating is water-soluble and dissolves quickly after swallowing.
  • The sugar coating protects against airborne active particles, moisture, and sunlight.
  • The sugar coating covers up unpleasant taste.
  • The colorful coating appeals visually.
  • Slow action.
Film-coated Tablet
Viagra-pills.jpg
  • Compressed tablet covered with a thin layer of water-insoluble polymer.
  • The film coating masks unpleasant tastes.
  • Easy to swallow.
  • Good appearance.
  • Slow action.
Enteric-coated Tablet
Omeprazole capsule.jpg
  • Tablets covered with a layer that is resistant to the acidic (i.e. pH ~3) environment of the stomach.
  • Dissolves in the alkaline (i.e. pH 7-9) environment of the intestine.
  • Protects stomach from potentially irritating drug.
  • Protects the drug from (partial) degradation in the stomach.
  • Slow action.
Other Routes
Dosage Form Characteristics Suitability/Advantages Disadvantages
Suppositories
GWS05030.jpg
  • Solid dosage form that is inserted into an orifice in the body where they soften, melt, and then dissolve.
  • Rectal suppositories can provide local and also systemic effect.
  • They come in different sizes, for adults and children.
  • Suitable when administration via oral route is difficult (e.g. nausea, intolerance, vomiting, or gastric pain) or when patients are uncooperative or have low consciousness. Also suitable when IV route is difficult.
  • Rapid action.
  • No first-pass metabolism.
  • Uncertain absorption.
  • Local irritation.
Vaginal suppositories
Handvaginalsuppositoryappl.png
  • Local effect.
  • Rapid action.
  • Local irritation.

Speed of Absorption via Oral Route[edit]

In order of fastest to slowest:

  1. Sublingual tablet
  2. Solution
  3. Suspension
  4. Powder
  5. Capsule
  6. Compressed tablet
  7. Sugar-coated tablet
  8. Enteric-coated tablet

Considerations when Prescribing Topical Medication[edit]

  • Always consider the effect of the vehicle. An occlusive vehicle enhances penetration of the active ingredient and improves efficacy. The vehicle itself may have a cooling, drying, emollient, or protective action. It can also cause side effects by being excessively drying or occlusive.
  • Match the type of preparation with the type of lesions. For example, avoid greasy ointments for acute weepy dermatitis.
  • Match the type of preparation with the site (e.g., gel or lotion for hairy areas).
  • Consider irritation or sensitization potential. Generally, ointments and w/o creams are less irritating, while gels are irritating. Ointments do not contain preservatives or emulsifiers if allergy to these agents is a concern.

WHO's 6-Steps to Good Prescribing[edit]

  • Step 1: Define the patient's problem.
  • Step 2: Specify the therapeutic objective.
  • Step 3a: Choose your standard treatment (P-drug).
  • Step 3b: Verify the suitability of your treatment (P-drug).
  • Step 4: Start treatment.
  • Step 5: Give information, instructions, and warnings.
  • Step 6: Monitor treatment and stop it if necessary.

Two additional steps have been proposed but they haven't been adopted by the WHO yet:

  • Step 7: Consider drug cost when prescribing.
  • Step 8: Use computers and other tools to reduce prescribing errors.


Indonesian Drug Classification[edit]

Bebas.jpg
Terbatas.jpg
Keras.jpg
Narkotika dan psikotropika.png
Free medicines or over-the-counter drugs. (Black outlined green dot)
Drugs freely available to the public (Obat Bebas).
Limited free medicines. (Black outlined blue dot)
Drugs available to the public only through Apotiks or licenced drug stores. Cautionary labelling required (Obat Bebas Terbatas).
Prescription drugs. (Black outlined red dot with "K")
Drugs available to the public on prescription only (Obat Keras).
Narcotic and Psychotropic Drugs. (Red outlined red cross)
Available to the public on prescription only and drugs in this list are under strict supervision by the Ministry of Health.

Pretest Questions[edit]

Batch 2011 lab session

Batch 2011[edit]

The most likely correct answer is bolded following the other (most likely wrong) choices.

  1. The best dosage form for applying on stomach folds is: powder, lotion, ointment, or cream?
  2. All these are advantages of transdermal patch except: local irritation, good adherence, long-term effect, or easy to stop?
  3. All of these provide a local effect except: rectal, vaginal, bronchal, or eye?
  4. The best dosage form for dandruff is: lotion, cream, ointment, or gel?
  5. A patient with no teeth must not be given: chewable tablets.
  6. The dosage form that allows absorption in the intestine is: enteric, film-coated, or sugar-coated?
  7. A solution is: homogenous, a solid in a liquid, or two liquids mixed together?
  8. An 8 month old baby must be given: oral drops.
  9. The advantage of ointment is that it is: occlusive, comfortable and best for cosmetic appearance.
  10. The advantage of lozenge is that it is: local.

See Also[edit]

Links[edit]