W2L1 Dosage forms PPT

Course Information

• Course Title: PHAR1035

• Subject: Dosage Forms

• Instructor: Katherine Baverstock

Learning Outcomes

• After completing this lecture, you should be able to:

  • Define what a medicine is and understand its main components.

  • Explain why active pharmaceutical ingredients (APIs) are rarely used alone for administration to patients.

  • Outline the main functions of excipients during pharmaceutical formulation.

  • Recognize some commonly used types of excipients.

  • Define what dosage forms are and describe the benefits of various dosage forms.

  • Describe the two main ways dosage forms are categorized.

  • Recognize different types of dosage forms: solid, semi-solid, and liquid.

  • Compare and contrast the uses, advantages, and disadvantages of different dosage forms.

What is a Medicine?

• A medicine consists of:

  • Active Ingredient: therapeutic molecule providing pharmacological effect.

  • Drug Delivery System: made of non-medicinal, inactive ingredients.

• Roles of inactive ingredients include:

  • Assisting in the manufacturing process

  • Delivering the therapeutic molecule to the target site

  • Ensuring dosage accuracy, especially for small doses

  • Stabilizing the medicine

  • Improving convenience for administration

Why Not Use Active Ingredients Alone?

• Active pharmaceutical ingredients (APIs) are rarely used alone due to:

  • Potency requiring very small quantities which can be unsafe from bulk material

  • Unpleasant smell or taste of some APIs

  • Chemical instability when exposed to unfavorable conditions (light, moisture, air)

  • Breakdown before reaching absorption site (e.g., acidic stomach environment)

Excipients

• Excipients are inactive ingredients that:

  • Have no pharmacological activity in the body

  • Serve as carriers for APIs

  • Act as manufacturing adjuvants

  • Regulate API release

• Selection of excipients is based on:

  • API's chemical stability

  • Required manufacturing processes

  • Body's metabolism of the API

Types of Excipients

• Fillers/Diluents: enhance size of tablets/capsules

• Binders: hold ingredients together in tablets

• Lubricants: prevent adherence to machinery

• Glidants: improve powder flow during manufacturing

• Coatings: improve appearance and protect ingredients

• Disintegrants: ensure breakdown in GI tract

• Preservatives: extend shelf life

• Flavours/Sweeteners: mask unpleasant tastes

• Colours: enhance aesthetic appeal

What is a Dosage Form?

• Definition: Physical form of a pharmaceutical product containing an API and excipients intended for patient administration.

• Dosage forms are categorized to deliver APIs to specific body areas.

• Area of study related to dosage forms: Pharmaceutics

Benefits of Dosage Forms

• Advantages include:

  • Accurate dosing and convenience without the need for measuring

  • Protection of APIs from environmental factors

  • Taste and odour masking

  • Allow targeted/localized delivery

  • Modify release profiles for sustained action

  • Tailor formulations to maximize benefits and minimize side effects

Classification of Dosage Forms

• Categorized by:

  • Physical Form: solids, semi-solids, liquids, gases

  • Route of Administration: multiple dosage forms can be used per route (oral, topical, inhaled, ophthalmic, otic, rectal, vaginal, parenteral)

Types of Dosage Forms by Physical Form:

• Solids: e.g., tablets

• Semi-solids: e.g., creams

• Liquids: e.g., suspensions

• Gases: e.g., inhalers

Solid Dosage Forms

• Tablets:

  • Most common, compact, and long shelf-life

  • Can include excipients for lubrication, disintegration, and taste masking

  • Disadvantages: local irritation, first pass metabolism impacts absorption, not viable for unconscious patients

• Sublingual and Buccal Tablets:

  • Dissolved in the mouth for rapid absorption; bypass stomach acid

  • Examples: angina treatments, nicotine therapy

  • Disadvantages: potential for oral irritation; not all drugs suitable for this route

• Chewable Tablets:

  • Designed for easy ingestion; good for those who struggle with swallowing

  • Examples: vitamins, antacids

  • Disadvantages: taste issues; risk of mistaken use for non-chewable tablets

• Capsules:

  • Easier to swallow, available in hard or soft shells

  • Excellent for taste masking or sustained release

  • Challenges in manufacturing

• Effervescent Tablets:

  • Dissolve in liquid before consumption; rapid onset of action

  • Disadvantages: larger size; complex manufacturing processes

• Lozenges:

  • Slow-dissolving for prolonged local effect; used for throat issues

• Powders:

  • Dry mixtures either for internal (to dissolve) or external use (dusting)

  • Include bulk powders and divided doses for unique needs.

Semi-Solid Dosage Forms

• Creams:

  • Emulsions for skin or mucous membranes; contain both oil and water phases

  • Advantages: localized effects, reduced systemic side effects

  • Disadvantages: local irritation, limited dose accuracy, storage challenges

• Ointments:

  • Greasy base with active ingredient for serious skin conditions

  • Not suitable for face; sticky texture

• Gels:

  • Water-based for applying soluble ingredients

• Suppositories:

  • Inserted rectally; melts at body temp for local/systemic effects

  • Advantages include systemic absorption without stomach inactivation

  • Disadvantages: inconvenient, local irritation, slow onset

• Pessaries:

  • Similar to suppositories but for vaginal insertion; distinctive shape and larger size for treatment.

Liquid Dosage Forms

• Liquid dosage forms for various administration routes; can be orally, topically, or injected

• Advantages include:

  • Aid for swallowing difficulties, faster absorption, tailored doses

• Disadvantages include:

  • Shorter shelf-life, requires measurement for dosing, may need special storage

• Simple Solutions:

  • Clear mixtures of active ingredients in solvent

• Linctus:

  • Viscous for cough relief; sweet but limited in diabetic conditions

• Suspensions:

  • Cloudy mixtures of insoluble particles; require shaking before use.

  • Examples: antibiotics, analgesics

• Lotions:

  • Thin applications for skin, either suspensions or creams.