W2P1 Exploring Dosage forms

Introduction to Dosage Forms

  • Instructor: Katherine Baverstock

  • Course Code: PHAR1035 - Exploring Dosage Forms

Learning Objectives

At the conclusion of this workshop you will be able to:

  • Identify and explain different dosage forms and their administration in the body.

  • Discuss how modification of dosage forms influences the release of active ingredients.

  • Explore formulations that overcome physical barriers to medication administration.

  • Understand how different formulations protect active ingredients and patients from adverse outcomes.

  • Identify reasons for using various formulations.

Understanding Medicines and Formulations

Definition of a Medicine

  • Contains an active ingredient: The drug that affects body changes, also known as the therapeutic molecule.

  • Includes inactive ingredients: Assist in packaging the active ingredient for manufacturing and global distribution.

  • Importance for pharmacists: Consider diverse methods to effectively deliver the therapeutic molecule into the body.

Routes of Administration

  • Defines how medications are introduced into the body:

    • Oral

    • Buccal

    • Sublingual

    • Dermal

    • Parenteral

    • Rectally

    • Vaginally

  • Utilization of different formulations for optimal absorption depending on the route.

Skin and Formulations

Overview of the Skin Structure

  • Layers: Epidermis, Dermis, Fatty Tissue

  • Components: Sweat glands, nerve endings, hair follicles, and oil glands.

Types of Skin Products

  • Products can target local or systemic effects:

    • Local effects: Applied for immediate site-specific application.

    • Systemic effects: Active ingredients penetrate the skin to reach the bloodstream.

  • Types of formulations discussed: Pastes, Ointments, Creams, Lotions, Gels, Patches.

Formulation Types

Pastes

  • Composition: Fatty base (e.g., petroleum jelly) with 25% solid powder mixed in.

  • Characteristics: Thick, do not melt at body temperature, offer prolonged skin contact, protect damaged skin.

  • Example Formula for Zinc Paste:

    • Starch: 25 grams

    • Zinc Oxide: 25 grams

    • White Soft Paraffin (Vaseline): 50 grams

Activities with Pastes

  • Application and observation of paste characteristics.

  • Use cases for nappy rash treatment and as a sunscreen, explaining paste efficacy in both scenarios.

Ointments

  • Characteristics: Greasy base, thick consistency, sticky texture.

  • Application: Acts as a vehicle for medications (e.g., corticosteroids, salicylic acid) and moisturizes dry skin.

  • Demonstration of application and characteristic evaluation on surfaces.

Creams and Lotions

  • Composition: Emulsions of oil and water, achieved with emulsifying wax.

  • Differences: Creams are thicker than lotions; both deliver active ingredients and provide moisture.

  • Comparative activity to evaluate behavior on surfaces (cream vs. lotion).

Gels

  • Definition: Lightest form of skin product in an alcoholic base.

  • Characteristics: Easy to apply, cooling effect, quick drying, suitable for hairy skin.

  • Discussion on advantages and disadvantages of quick-drying properties.

Patches

  • Definition: Sticky bandages embedding therapeutic molecules.

  • Usage: Slow-release delivery of medication, such as for pain management or smoking cessation (e.g., nicotine patches).

Challenges in Medication Formulations

Reflux and Colic Treatment

  • Exploration of formulations for reflux and colic, with definitions and causes.

  • Reflux: Acidic stomach condition often treated with antacids to neutralize acidity.

  • Consideration of pharmaceutical forms (e.g., liquid vs. tablet) for effectiveness in treatment.

Protection of Active Ingredients

  • Some active ingredients are acid labile, at risk from stomach acid.

  • Formulations can provide protection:

    • Enteric coatings

    • Sublingual tablets

    • Injections/Patches

Patient Safety

  • Adverse effects of certain medications (e.g., NSAIDs) leading to stomach issues like ulcers.

  • Strategies for mitigation:

    • Use of enteric coatings

    • Behavior modifications (e.g., taking with food).

Addressing Physical Barriers

  • Considerations for patients with conditions affecting medication administration:

    • Dysphagia

    • Unconscious, etc.

  • Need for adaptive formulations to cater to such scenarios.

Enhancing Shelf-life of Medications

Stability and Packaging

  • Many liquid medications lack stability; solutions include powder forms for reconstitution.

  • Considerations in storage:

    • Light resistance: Techniques such as opaque packaging to protect active ingredients.

Dosage Forms of Paracetamol

  • Oral dosage forms:

    • Standard tablets, extended-release tablets, capsules, effervescent tablets, suspension.

  • Non-oral dosage forms:

    • Suppositories, injections; knowing when to use each formulation is crucial.