Drug Dosage Forms - Pharmacy Test Prep Study Guide NAPLEX, PTCB, NCLEX
Summary
This video explains drug dosage forms, detailing their necessity for accurate and effective drug delivery. It classifies them by physical form (solid, liquid, semi-solid) and provides examples for each. Solid forms include capsules and tablets with various sub-types. Liquid forms cover solutions, suspensions, syrups, emulsions, elixirs, and tinctures. Semi-solid forms discussed are ointments, pastes, creams, and gels. The video also highlights special labeling requirements for certain dosage forms.
Key Insights
Dosage forms are necessary to overcome challenges in delivering pure drugs.
Dosage forms are necessary because there are challenges to easily and accurately delivering a drug in its pure form. They facilitate accurate dosing, optimal drug action, protect the drug from the environment or stomach acid, allow for placement in specific body areas, enable sustained release, and mask bad tastes or odors, while also addressing solubility issues.
Liquid dosage forms offer quicker action and are easier to swallow, especially for certain populations.
Liquid dosage forms have a quicker onset of action than solids as dissolution is not required. They are easier to swallow, making them suitable for pediatrics or geriatrics, and allow for alternate administration sites like injections or drops.
Elixirs and tinctures are hydroalcoholic solutions requiring caution due to alcohol content.
Elixirs and tinctures are non-aqueous hydroalcoholic solutions where alcohol aids drug dissolution. Caution is advised due to potential interactions with other medications, especially for pediatric and geriatric patients. Tinctures have a higher alcohol concentration than elixirs.
Specific labels guide the safe and effective use of certain dosage forms.
Certain dosage forms require specific labels for safe and effective use: 'do not crush or chew' for extended-release tablets, 'shake well' for suspensions, 'caution contains alcohol' for elixirs and tinctures, and 'for external use only' for creams, ointments, and gels.
Sections
Introduction to Dosage Forms
Dosage forms are the formulated delivery methods for drugs presented in the market.
Dosage forms are the way drug products are formulated for delivery to the body and presented in the market. Examples include tablets, capsules, solutions, and creams.
Dosage forms contain active ingredients and inactive excipients.
Dosage forms contain the active ingredient (the drug) and chemically inactive or inert ingredients. These inactive ingredients include additives, diluents, excipients (as carriers), and preservatives to prevent bacterial growth.
Dosage forms are necessary to overcome challenges in delivering pure drugs.
Dosage forms are necessary because there are challenges to easily and accurately delivering a drug in its pure form. They facilitate accurate dosing, optimal drug action, protect the drug from the environment or stomach acid, allow for placement in specific body areas, enable sustained release, and mask bad tastes or odors, while also addressing solubility issues.
Dosage forms are classified by route or physical form.
Dosage forms can be classified by route of administration (oral, topical, rectal, parenteral, vaginal, inhaled, otic, ophthalmic) or by physical form (solid, liquid, semi-solid). This video will focus on classification by physical form.
Solid Dosage Forms
Solid dosage forms offer ease of packaging, storage, transport, and accurate dosing.
Solid dosage forms are easy to package, store, transport, and dispense. They offer very accurate dosing and typically have little or no taste or smell.
Capsules contain drugs within a gelatin shell that dissolves in the stomach.
Capsules consist of an enclosed drug within a gelatin shell. After 10-30 minutes in the stomach, the gelatin dissolves, releasing the drug. They minimize bad tastes/odors, are available in various colors/sizes for easy identification, and come in hard and soft gelatin types.
Tablets are the most popular dosage form, made by molding or compression.
Tablets are the most popular dosage form, formed in molds or by mechanical compression. Dissolution is required for the drug's pharmacologic effect. Types include chewable, enteric-coated (dissolve in intestine), extended-release (don't crush/chew), buccal (dissolve between cheek/gum), sublingual (dissolve under tongue), film-coated (mask taste/odor/protect from elements), pellets (subdermal implant), and effervescent (dissolve in water).
Lozenges dissolve slowly in the mouth for prolonged throat or mouth contact.
Lozenges are hard, flavored dosage forms that dissolve slowly in the mouth, keeping the drug in contact with the throat or mouth longer. Also known as troches or pastilles, examples include cough drops.
Suppositories are solid forms for insertion into body cavities to release drugs.
Suppositories are solid dosage forms designed for rectal, vaginal, or urethral insertion. Rectal suppositories melt or dissolve after insertion, releasing the drug over time for local or systemic effect. Vaginal suppositories are sometimes called inserts.
Powders are finely ground drug mixtures for external or internal use.
Powders are finely ground mixtures of dry ingredients and drug. They can be used externally (dusted on) or internally (dissolved in water before use).
Granules are larger, irregular pieces derived from powders, offering better stability.
Granules are powders that have been wetted, dried, and ground into coarser pieces. They have a larger particle size than powders and are more stable. Water can be added at dispensing for a solution/suspension, or they can be added to soft food.
Liquid Dosage Forms
Liquid dosage forms offer quicker action and are easier to swallow, especially for certain populations.
Liquid dosage forms have a quicker onset of action than solids as dissolution is not required. They are easier to swallow, making them suitable for pediatrics or geriatrics, and allow for alternate administration sites like injections or drops.
Solutions are homogeneous mixtures where the drug is fully dissolved.
Solutions are homogeneous mixtures of one or more dissolved drugs (solute) in a liquid vehicle (solvent). No drug particles are seen, and they don't require shaking. They have internal and external uses. Aqueous solutions use water as the solvent, while non-aqueous solutions use other solvents like alcohol.
Suspensions contain undissolved drug particles that settle and require shaking.
Suspensions are mixtures of very small, undissolved drug particles in a liquid. Drug particles can be seen floating and settle to the bottom, requiring a 'shake well' label and use before shaking for a correct dose. They are used internally and externally.
Syrups are thick, sweet aqueous solutions commonly used for palatability.
Syrups are viscous, thick aqueous solutions containing a concentrated mixture of sugar or artificial sweetener and dissolved drug. Their sweetness aids compliance, especially in pediatrics. They are good for masking bitter tastes and do not require shaking.
Emulsions are mixtures of immiscible liquids (e.g., oil and water) stabilized by emulsifying agents.
Emulsions are mixtures of liquids that usually don't mix, like oil and water. One liquid is dispersed in the other in small particles, held together by an emulsifying agent (e.g., acacia) with hydrophilic and lipophilic properties. Examples include some hormone lotions and TPN.
Elixirs and tinctures are hydroalcoholic solutions requiring caution due to alcohol content.
Elixirs and tinctures are non-aqueous hydroalcoholic solutions where alcohol aids drug dissolution. Caution is advised due to potential interactions with other medications, especially for pediatric and geriatric patients. Tinctures have a higher alcohol concentration than elixirs.
Semi-Solid Dosage Forms
Semi-solid dosage forms are topical applications, thicker than liquids but softer than solids.
Semi-solid dosage forms are too thick to be liquid but too soft to be solid. They are intended for topical application to the skin, mucous membranes, or other body areas.
Ointments are smooth, oily preparations for external application and protection.
Ointments are smooth, oily semi-solid preparations for external application to skin or mucous membranes. They can act as vehicles for drugs, emollients, or skin protectants, typically for local effect, excluding specific exceptions like nitroglycerin ointment.
Pastes are stiffer, less greasy, and more water-based than ointments, suitable for oozing lesions.
Pastes are ointment-like preparations but stiffer, less greasy, and more water-based. They are used for application to oozing or weeping lesions because of their ability to absorb water.
Creams are semi-solid emulsions suitable for larger application areas, less greasy than ointments.
Creams are semi-solid emulsions (water and oil) containing drug suspensions or solutions for external use. They are a better choice for larger areas compared to ointments due to reduced greasiness.
Gels are viscous solutions with a solid diffused through a liquid, appearing sticky and transparent.
Gels are semi-solid solutions consisting of a solid diffused through a viscous liquid. They are sticky, transparent, and quickly absorbed by the skin.
Ointments, pastes, creams, and gels generally require an 'external use only' label.
Ointments, pastes, creams, and gels are typically for external use only and should bear that label.
Summary and Key Labels
Dosage forms are crucial for drug formulation and delivery.
Dosage forms are essential for formulating and delivering drugs effectively. Classification by physical form includes solid, liquid, and semi-solid types.
Specific labels guide the safe and effective use of certain dosage forms.
Certain dosage forms require specific labels for safe and effective use: 'do not crush or chew' for extended-release tablets, 'shake well' for suspensions, 'caution contains alcohol' for elixirs and tinctures, and 'for external use only' for creams, ointments, and gels.
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