Drug Classification and Dosage Forms

Drug Classification

• Drugs are categorized based on physical state, route of administration, site of application, and uses.
• Physical forms include solid (e.g., tablets, capsules, pills), semi-solid (e.g., ointments, creams, gels, pastes), liquid (e.g., syrups, elixirs, suspensions, emulsions), and gaseous (e.g., inhalers, aerosols).
• Routes of administration include oral, parenteral, sublingual, intranasal, intraocular, intra respiratory, rectal, vaginal, and urethral.
• Sites of application can be skin, eye, tooth, hand, foot, hair, nasal.
• Uses can be internal or external.

Dosage Form Classification

• Dosage forms are physical preparations of drugs for administration.
• Key factors considered in selecting a suitable dosage form include patient age/condition, route of administration, drug substance properties, and product stability.

Liquid Dosage Forms

• Elixirs are liquid preparations containing drugs and excipients for oral administration.
• Emulsions are water-based suspensions of oils and fats, stabilized by emulsifying agents.
• Suspensions are liquid preparations where active components are dispersed in a suitable medium, typically requiring shaking for uniform distribution.
• Gargles are concentrated aqueous solutions used for external application, typically to treat throat infections.
• Gels are dispersions of medicaments in water, often used as antacids
• Other liquid dosage forms include lotions, liniments (applied with friction), and mixtures (containing multiple medications).

Solid Dosage Forms

• Powders are finely fragmented solid particles.
• Tablets are solid medication forms, often with excipients.
• Granules are aggregated particles.
• Capsules are gelatin or other materials used to enclose drugs.
• Pills are small tablets containing excipients.
• Lozenges are solid, sugar or gum-based formulations used for mouth and throat issues.
• Suppositories are solid medications placed in body cavities other than the mouth (e.g., rectum, vagina).

Semisolid Dosage Forms

• Ointments are semisolid preparations for external use, possibly containing medications.
• Creams are semisolid preparations, with or without medications, and typically contain fatty bases.
• Pastes are semisolid preparations with a significant proportion of finely powdered medicaments.
• Gels (external use) contain hydrophilic or hydrophobic bases and gelling agents.

Gaseous Dosage Forms

• Aerosols are particles of solid or liquid substances dispersed in gas for application to the respiratory tract.
• Inhalations are liquid preparations intended for internal use and dispersed/suspended in a propellant.
• Sprays are medication aerosols utilizing an atomizer or nebulizer for application in the nose or throat, often alcohol-containing.

Adverse Reactions

• Adverse reactions can be allergic (hives, itching, edema) or anaphylactic (respiratory distress, cardiovascular collapse).

Drug Interactions

• Drugs can interact with other drugs, foods, or juices.

Six Rights of Medication Administration

• The six rights of medication administration are right drug, right time, right dose, right patient, right route, and right documentation.

Factors Influencing Drug Action

• Factors influencing drug action include patient age, weight, metabolic rate, illness, psychological aspects (placebo effect), tolerance/dependence, and cumulative effect.

Drug Action

• Drugs typically have a desired effect but can also have adverse effects (side effects).

Pharmaceutical Dosage Forms

• Pharmaceutical dosage forms are the physical forms in which medications are prepared for administration to patients.
• Examples include tablets, capsules, syrups, suspensions, creams, ointments, inhalers, injections, and patches.

Advantages of Different Dosage Forms

• Topical: Target delivery, reduced side effects, easy application.
• Parenteral: Suitable for non-orally absorbable drugs, avoids first-pass metabolism, rapid onset, complete bioavailability, and prolonged action.
• Liquid: Easy swallowing, suitable for elderly and children, improved taste, and flexible dosing.
• Solid: Stability, accurate dosing, easy administration, sustained release options, and combination therapy potential.

Considerations in Selecting a Dosage Form

• Patient age/condition, route of administration, drug properties, and product stability are considered when selecting a dosage form.