Hoja de repaso: Pharmaceutical Formulation and Dosage Forms

📋 Course Outline

1. Pharmaceutical Forms Classification
2. Solid Dosage Forms
3. Liquid Dosage Forms
4. Semi-Solid Dosage Forms
5. Excipients and Their Effects
6. Active Principles vs Excipients
7. Storage Conditions for Medications
8. Preparation and Manufacturing
9. Special Tablet Types
10. Drug Formulation Definitions

📖 1. Pharmaceutical Forms Classification

🔑 Key Concepts & Definitions

• Pharmaceutical form: The association of active principles (active ingredients) and excipients to create a medication, designed to be suitable for specific routes of administration. It is also called forme galénique or forme médicamenteuse (source: provided content).

• Active principle: The component responsible for the therapeutic activity of the medication. It can originate from various sources such as plant, animal, microbial, mineral, synthetic, or biotechnological origins (source: provided content).

• Excipients: Substances other than the active principle included in a medication to provide consistency, taste, color, or aid in formulation and preservation. Some excipients have notable effects, such as lactose or peanut oil, which can cause allergic reactions or intolerance (source: provided content).

• Classification of pharmaceutical forms:

  • Solid forms: Include powders, granules, capsules, and tablets.
  • Liquid forms: Include syrups, suspensions, emulsions, ampoules, and solutions for injection.
  • Semi-solid forms: Include ointments, creams, gels, pastes, suppositories, and lyophilisates (Lyoc) (source: provided content).

📝 Essential Points

• The formulation involves combining active principles with excipients to produce a medication suitable for administration.
• Pharmaceutical forms are adapted to specific routes of administration, such as oral, rectal, or injectable.
• The pharmaceutical form is a fundamental concept that encompasses the physical state and presentation of the medication.
• Solid forms include powders, granules, capsules, and tablets, each with specific characteristics and uses.
• Liquid forms include solutions, suspensions, emulsions, and injectable solutions, prepared for various routes including oral and parenteral.
• Semi-solid forms are mainly for topical or mucosal application, such as ointments, creams, and gels.
• Excipients serve roles beyond active effects, such as aiding in manufacturing, stability, and patient acceptability.

💡 Key Takeaway

Pharmaceutical forms are categorized into solid, liquid, and semi-solid types, each created by combining active principles with excipients to produce medications tailored for specific routes and purposes, ensuring efficacy, stability, and patient compliance.

📖 2. Solid Dosage Forms

🔑 Key Concepts & Definitions

• Solid dosage forms: Pharmaceutical preparations in solid state, including powders, granules, capsules, and tablets, designed for oral or rectal administration.

• Powders: Particles of solid, dry, and more or less fine material containing one or more active principles. They can be used as active ingredients, excipients, or as a pharmaceutical form. They may be presented in multidose or monodose packaging.

• Granules: Prepared from grains of solid, dry material, each containing an aggregate of powder particles. They are small, vermiculated grains of relatively uniform size, used in multi-dose (in flasks with water to form solutions or suspensions) or single-dose forms (in sachets, small packages, or capsules).

• Capsules: Solid preparations with an envelope (hard or soft) of variable shape and capacity, generally containing a unit dose of active principle. Types include:

  • Hard capsules (gélules): Composed of two parts (body and cap), made of gelatin, with low water content.
  • Soft capsules: Thicker, flexible, single-part shells, often containing liquids or solids dissolved in a gel matrix.

• Comprimés (Tablets): Solid preparations formed by compressing a fixed volume of particles, containing active principles and excipients. They can be:

  • Naked (non-coated): Simple compressed tablets.
  • Enrobed (coated): Covered with a protective layer for protection or masking taste.
  • Special tablets: Effervescent, gastro-resistant, dispersible, or orodispersible, designed for specific release or administration.

• Effervescent tablets: Designed to dissolve rapidly (less than 5 minutes) in water, releasing carbon dioxide due to reaction between acids and carbonates.

• Gastro-resistant tablets: Coated to resist stomach acid, releasing the active in the intestines; they should not be crushed.

• Dispersible and Orodispersible tablets: Formulated to disperse or dissolve quickly in water or in the mouth, respectively, for rapid administration.

• Lyophilisates (Lyoc): Freeze-dried oral forms that dissolve instantly in the mouth upon contact with saliva, without needing water.

• Suppositories: Solid, single-dose preparations designed for rectal administration, containing active principles dispersed or dissolved in a suitable excipient that melts or dissolves at body temperature.

📝 Essential Points

• Solid dosage forms include powders, granules, capsules, and tablets, each with specific preparation methods and characteristics.
• Tablets are produced by compression of particles; they can be non-coated or coated for protection, taste masking, or targeted release.
• Special tablets like effervescent, gastro-resistant, dispersible, and orodispersible are designed for specific administration routes or release profiles.
• Lyophilisates dissolve rapidly in the mouth, providing quick onset of action.
• Suppositories are solid, rectally administered forms, containing active principles in a suitable excipient that melts or dissolves at body temperature.

💡 Key Takeaway

Solid dosage forms are versatile and tailored to specific administration needs, with various types designed to optimize drug stability, release, and patient compliance.

📖 3. Liquid Dosage Forms

🔑 Key Concepts & Definitions

• Syrups: Liquid preparations characterized by a high concentration of sugar, which provides viscosity, preserves the medication, and masks unpleasant tastes of active principles. Example: a syrup containing active medication dissolved in a sugary solution.

• Suspensions: Liquid formulations consisting of very small insoluble solid particles dispersed uniformly in a liquid medium. They require agitation before use to maintain homogeneity.

• Emulsions: Mixtures of two immiscible liquids where one liquid is dispersed in the other with the help of a surfactant (tensioactive). Comprise a phase of water and a phase of oil.

• Injectable solutions: Liquid preparations intended for parenteral administration, available as solutions, suspensions, or emulsions. They are sterile, ready-to-use, or require reconstitution before use.

• Ampoules: Small sealed vials made of glass containing a single dose of liquid medication, typically for parenteral use. They are hermetically sealed to preserve sterility.

• Vials: Containers for liquid medications, made of glass or plastic, designed to hold multiple doses or a single dose. They can be sealed with a stopper and are used for storing injectable solutions.

📝 Essential Points

• Preparation of syrups, suspensions, and emulsions involves dissolving or dispersing active principles in appropriate vehicles, with sugars for syrups, insoluble particles for suspensions, and immiscible liquids for emulsions.

• Uses of syrups: Mainly for oral administration, especially suitable for children due to masking of taste and ease of swallowing.

• Uses of suspensions and emulsions: Also for oral use, but require shaking before administration to ensure uniformity.

• Types of injectable solutions: Include solutions, suspensions, and emulsions, all sterile and suitable for parenteral routes.

• Containers: Ampoules are used for single-dose sterile solutions, while vials can contain multiple doses and are sealed with stoppers to maintain sterility.

💡 Key Takeaway

Liquid dosage forms such as syrups, suspensions, emulsions, and injectable solutions are essential for diverse therapeutic needs, with specific preparation characteristics and container types like ampoules and vials ensuring proper administration and stability.

📖 4. Semi-Solid Dosage Forms

🔑 Key Concepts & Definitions

• Semi-solid dosage forms are preparations designed for topical or mucosal application, intended to exert local effects or facilitate absorption of active principles. They include ointments, creams, gels, and pastes.

• Ointments are monophase preparations, either lipophilic or hydrophilic, in which one or more active principles are dispersed or dissolved. They are used mainly for topical application on the skin or mucous membranes.

• Creams are multi-phase preparations combining lipophilic and hydrophilic components, forming a semi-solid emulsion suitable for topical use. They are less greasy than ointments and often have a lighter texture.

• Gels are liquids gellified with a sensation of refreshment, either hydrogels (water-based) or alcohol-based, used for topical or mucosal application. They are characterized by their gelled, often transparent, structure.

• Pastes are preparations containing high proportions of finely dispersed powders within a base, providing a thick, pasty consistency suitable for topical application.

📝 Essential Points

• Semi-solid forms are primarily used for topical and mucosal applications, allowing localized treatment or absorption of active principles.

• Uses and Characteristics:

  • Ointments are lipophilic or hydrophilic, suitable for occlusive, protective, or medicated purposes.
  • Creams are multi-phase, combining lipophilic and hydrophilic elements, offering a less greasy alternative to ointments.
  • Gels provide a refreshing sensation, often used for mucosal or skin application, with quick absorption.
  • Pastes contain high powder content, providing a thick, adherent layer on the skin or mucosa.

• Differences in Composition and Application:

  • Ointments are monophase, either lipophilic or hydrophilic.
  • Creams are emulsions with distinct phases, offering a lighter texture.
  • Gels are gelled liquids, often transparent and quick-drying.
  • Pastes are powder-rich, thick, and adhesive.

• These forms are designed to optimize drug delivery, protection, or local action, with their choice depending on the desired effect, site of application, and patient comfort.

💡 Key Takeaway

Semi-solid dosage forms such as ointments, creams, gels, and pastes are tailored for topical and mucosal use, differing mainly in composition and texture to suit specific therapeutic and application needs.

📖 5. Excipients and Their Effects

🔑 Key Concepts & Definitions

• Excipients: Substances in a medication, other than the active principle, intended to provide properties such as consistency, taste, and color, while avoiding interaction with the active ingredient. Some excipients have notable effects, which can influence safety and efficacy (source: Dr. CHABANE).

• Excipients with notable effects: Certain excipients, such as lactose or peanut oil, can cause adverse reactions like allergies or intolerances. Their presence requires specific precautions, especially in generics or formulations for sensitive populations (source: Dr. CHABANE).

• Difference between active principles and excipients:

  • Active principles: Responsible for the pharmacological action, with origins that can be plant, animal, microbial, mineral, synthetic, or biotechnological.
  • Excipients: Do not possess therapeutic effects but are essential for preparation, manufacturing, and preservation of the medication (source: Dr. CHABANE).

📝 Essential Points

• Excipients serve to improve the physical and sensory properties of medications, such as providing consistency, taste, and color.
• Some excipients have notable effects that can lead to allergic reactions or intolerance, necessitating careful selection and labeling.
• The presence of excipients with notable effects influences the safety profile and specific precautions for certain patient groups.
• The primary role of excipients is to facilitate the formulation, manufacturing, and stability of medications, not to contribute to therapeutic activity.
• The difference between active principles and excipients lies in their origin, function, and pharmacological activity: active principles are responsible for therapeutic effects, while excipients are inert carriers or additives.

💡 Key Takeaway

Excipients are vital non-active components that enhance the physical and sensory qualities of medications, but some possess notable effects that require careful consideration to ensure safety and efficacy.

📖 6. Active Principles vs Excipients

🔑 Key Concepts & Definitions

• Active Principles (AP): Substances responsible for the pharmacological activity of a medication. They are the core components that produce the therapeutic effect.
• Excipients: Substances in a medication that are not responsible for therapeutic activity but serve purposes such as formulation, preservation, or improving taste, color, and consistency. They help in preparing, manufacturing, and maintaining the stability of the medication.
• Sources of Active Principles: Active principles can originate from various sources including plant, animal, microbial, mineral, synthetic, and biotechnological origins. These sources determine the nature and properties of the active principles used in medications.
• Function of Active Principles: Responsible for the pharmacological activity, meaning they produce the intended therapeutic effect in the patient.
• Function of Excipients: Used for formulation purposes such as providing consistency, taste, color, and aiding in preservation. Some excipients may have effects not related to pharmacology, known as excipients with effects notoire (noted effects).

📝 Essential Points

• Active principles are the core therapeutic agents in medications, responsible for the pharmacological effect.
• Excipients are added to medications to facilitate formulation, stability, and administration, but do not have a direct therapeutic effect.
• Active principles have diverse origins: plant, animal, microbial, mineral, synthetic, and biotechnological sources.
• Excipients are chosen for their roles in formulation and preservation, and some may have notable effects (excipients à effet notoire), such as lactose or peanut oil.
• The difference between active principles and excipients lies in their origin, function, and therapeutic effect: APs produce pharmacological activity, while excipients support formulation and stability without direct pharmacological action.

💡 Key Takeaway

Active principles are the pharmacologically active components responsible for therapeutic effects, whereas excipients are inert substances that support the formulation, stability, and administration of medications without contributing to their pharmacological activity.

📖 7. Storage Conditions for Medications

🔑 Key Concepts & Definitions

Storage conditions refer to the specific environmental parameters required to maintain the stability, efficacy, and safety of medications. These include temperature, light exposure, and humidity levels, which are critical for preserving the integrity of pharmaceutical products.

Temperature requirements specify the optimal temperature range for storing medications:

• Refrigerator storage: +2°C to +8°C
• Freezer storage: below -15°C
• Room temperature: 15°C to 25°C
• Frais (cool): +8°C to +15°C

Light exposure considerations involve protecting medications from light, which can degrade certain active principles, especially in multi-dose containers. Storage in opaque or light-resistant packaging is often recommended.

Humidity considerations involve storing medications in conditions that prevent moisture absorption, which can compromise stability, especially for powders, granules, and certain semi-solid forms. Medications should be kept in dry environments, away from humidity sources.

Labeling and expiration date considerations include:

• Clearly indicating the use before date (first day of the month).
• Marking the expiry or expiration date (last day of the month).
• Noting special instructions for storage conditions, especially after opening (e.g., "store in refrigerator," "use within 30 days after opening").

📝 Essential Points

• Medications must be stored according to manufacturer instructions, which are defined by the conditions in their packaging.
• Storage in refrigerators (+2°C to +8°C) is recommended for certain medications to prevent degradation.
• Freezer storage (< -15°C) is used for medications requiring very low temperatures.
• Room temperature storage (15°C to 25°C) is suitable for most medications not requiring special conditions.
• Medications sensitive to light should be stored in opaque containers or protected from exposure.
• Humidity must be minimized; medications should be kept in dry environments, away from moisture.
• Proper labeling includes expiration dates and storage instructions, ensuring safe and effective use.
• For multidoses, the expiration date after opening must be observed, as specified on the packaging or notice.

💡 Key Takeaway

Proper storage conditions—temperature, light, and humidity—are essential to maintain medication stability and efficacy, with clear labeling and expiration date management ensuring safe use over time.

📖 8. Preparation and Manufacturing

🔑 Key Concepts & Definitions

• Formulation: The process of associating active principles and excipients to create a medication, resulting in a specific pharmaceutical form suitable for administration (source: "Forme sous laquelle sont associés les principes actifs et les excipients pour constituer un médicament").
• Preparation process: The series of steps involved in creating a pharmaceutical form, including mixing, compression, coating, and sterilization, to ensure the final product meets quality standards.
• Manufacturing conditions: The specific environmental and technical parameters during production, such as temperature, humidity, and sterilization methods, which are crucial for maintaining medication quality and efficacy.

📝 Essential Points

• Formulation involves combining active principles with excipients to produce the desired pharmaceutical form, tailored to the route of administration.
• Preparation steps vary depending on the dosage form but generally include mixing ingredients, compressing powders into tablets, coating tablets for protection or controlled release, and sterilizing products to eliminate microbial contamination.
• Manufacturing conditions must be carefully controlled; for example, sterilization ensures microbial safety, and environmental controls prevent degradation of sensitive active principles.
• Different pharmaceutical forms require specific manufacturing processes: powders and granules involve mixing and possibly drying; capsules and tablets involve compression and encapsulation; coatings require specialized techniques; sterilization is essential for injectable forms and some semi-solid preparations.
• Quality assurance depends heavily on maintaining optimal manufacturing conditions, which directly influence the safety, stability, and efficacy of the final medication.

💡 Key Takeaway

Effective pharmaceutical manufacturing combines precise formulation, controlled processing steps, and strict environmental conditions to produce safe, effective, and high-quality medications.

📖 9. Special Tablet Types

🔑 Key Concepts & Definitions

• Effervescent tablets: Special tablets designed to dissolve rapidly in water, releasing carbon dioxide due to the reaction between acids and carbonates, leading to quick disintegration within 5 minutes.

• Gastro-resistant tablets: Tablets with an enrobing coating that resists dissolution in the stomach’s acidic environment, ensuring the release of the active principle in the intestines. They should not be crushed to maintain their protective properties.

• Dispersible tablets: Tablets intended to be dispersed in water before administration, facilitating easier swallowing and rapid disintegration in the liquid medium.

• Sublingual tablets: Tablets formulated to dissolve quickly under the tongue, allowing absorption directly into the bloodstream through the mucous membranes, bypassing the gastrointestinal tract.

• Design and purpose of special tablets: These tablets are tailored for targeted release and specific administration routes, such as protecting the active ingredient from gastric acid (gastro-resistant), enabling rapid onset (sublingual, dispersible), or ensuring quick dissolution (effervescent).

• Characteristics and handling of special tablets: Special tablets often have unique coatings or compositions that require careful handling, such as avoiding crushing gastro-resistant tablets to preserve their protective coating, or ensuring dispersible tablets are fully dissolved before ingestion.

📝 Essential Points

• Effervescent tablets contain substances that react with water to produce gas, facilitating rapid dissolution and absorption.

• Gastro-resistant tablets are coated to withstand stomach acid, releasing their active in the intestines; crushing these tablets compromises their protective coating.

• Dispersible tablets are designed to be broken down in water, making them suitable for patients who have difficulty swallowing.

• Sublingual tablets dissolve quickly under the tongue, providing rapid absorption and onset of action.

• The design of these special tablets aims to optimize drug stability, targeted delivery, and patient compliance, with specific handling instructions to maintain their efficacy.

💡 Key Takeaway

Special tablet types are engineered to improve drug delivery and patient convenience through targeted release mechanisms and specific administration routes, requiring careful handling to preserve their unique properties.

📖 10. Drug Formulation Definitions

🔑 Key Concepts & Definitions

Pharmaceutical form
The specific form in which a medication is prepared by combining active principles and excipients to create a medicinal product. It is designed to suit the intended route of administration and ensure proper delivery of the active substance.

Galenic form
Synonymous with pharmaceutical form; it refers to the form of a medicinal product as prepared and designed for administration, based on galenic principles of drug formulation.

Medicament form
Another term for pharmaceutical or galenic form, emphasizing the physical presentation of the medication as a prepared dosage for therapeutic use.

📝 Essential Points

• A medicament is composed of active principles (PA) plus excipients, and its form is tailored to the route of administration (e.g., oral, rectal, injectable).
• The pharmaceutical form includes the association of active principles and excipients, which together constitute the medication.
• The galenic form is the specific physical form of the medication, such as powders, capsules, tablets, solutions, or semi-solids.
• The medicament form is used interchangeably with pharmaceutical and galenic forms, referring to the final prepared state of the drug.
• The formulation involves selecting the appropriate galenic form to optimize drug stability, bioavailability, and patient compliance.

💡 Key Takeaway

The pharmaceutical, galenic, and medicament forms are terms describing the physical presentation of a drug, created by combining active principles with excipients to ensure proper administration and therapeutic effect.

📊 Synthesis Tables

Category	Examples / Characteristics	Route of Administration	Key Features	Authors / References
Pharmaceutical Forms	Active principles + excipients; classified as solid, liquid, semi-solid	Oral, rectal, injectable, topical	Formulation adapts to route; ensures stability and efficacy	Provided content
Solid Dosage Forms	Powders, granules, capsules, tablets, lyophilisates, suppositories	Oral, rectal	Compression, coating, special release profiles	Provided content
Liquid Dosage Forms	Syrups, suspensions, emulsions, solutions, ampoules, vials	Oral, parenteral	Viscosity, sterility, dispersion, solubilization	Provided content

⚠️ Common Pitfalls & Confusions

1. Confusing pharmaceutical form with dosage form—the former encompasses the entire formulation concept, the latter refers to specific physical states.
2. Mistaking effervescent tablets for regular tablets; they dissolve rapidly and release CO₂.
3. Overlooking the importance of coatings like gastro-resistant or film coatings for targeted release.
4. Assuming all liquid forms are suitable for injection; many are oral only.
5. Misidentifying lyophilisates as standard tablets; they require reconstitution and dissolve instantly in the mouth.
6. Ignoring the role of excipients in causing allergies or intolerance, e.g., lactose or peanut oil.
7. Confusing suspensions with solutions; suspensions contain insoluble particles needing agitation.

✅ Exam Checklist

• Define pharmaceutical form and explain its significance in drug formulation.
• Describe the differences between solid, liquid, and semi-solid pharmaceutical forms, including examples.
• Know the classification and characteristics of solid dosage forms, including powders, granules, capsules, tablets, and suppositories.
• Understand the special types of tablets: effervescent, gastro-resistant, dispersible, and orodispersible, and their specific uses.
• Explain the preparation and characteristics of lyophilisates and their advantages.
• Describe the main liquid dosage forms: syrups, suspensions, emulsions, solutions, ampoules, and vials.
• Know the purpose and composition of excipients, including their effects and potential adverse reactions.
• Differentiate between active principles and excipients in formulations.
• State storage conditions necessary for medications to maintain stability.
• Outline basic principles of preparation and manufacturing of pharmaceutical forms.
• Recognize the importance of special tablet types for targeted release and patient compliance.
• Understand the definitions related to drug formulation, including forme galénique and forme médicamenteuse.