Fiche de révision : Medicinal Product Knowledge

📋 Course Outline

1. Medicinal Product Definitions
2. Pharmaceutical Legal Categories
3. Drug Discovery Strategy
4. Molecular Modeling Applications
5. Me-too Drugs and NSAIDs
6. Clinical Drug Development
7. Clinical Trial Phases
8. Pharmacokinetic Pathway
9. Drug Quality Control
10. Dosage Forms and Administration
11. Prescription Rules

📖 1. Medicinal Product Definitions

🔑 Key Concepts & Definitions

• Active ingredient : the natural, chemical, or biotechnological substance responsible for the therapeutic action of a medicinal product
• Excipient : a natural or synthetic substance that facilitates administration, formulation, and preservation of the active ingredient and must be inert toward the organism and the active ingredient
• Medicinal product : Code de la Santé Publique — A medicinal product is a substance or composition presented as having curative or preventive properties, or capable of diagnosing, restoring, correcting, or modifying physiological functions through pharmacological, immunological, or metabolic action.

📝 Essential Points

📌 A medicinal product may be defined by presentation, by function, or by composition, including certain dietary products containing chemical or biological substances that confer therapeutic-dietetic properties.

💡 Memory Hook

Presentation identifies what a product appears to be, whereas function identifies what it does.

📖 2. Pharmaceutical Legal Categories

🔑 Key Concepts & Definitions

• Pharmaceutical specialty : a medicine prepared in advance by the pharmaceutical industry, presented in specific packaging, given a special name, and requiring marketing authorization for commercialization
• Magistral preparation : a medicine prepared according to a prescription for a specific patient because no suitable authorized pharmaceutical specialty is available
• Pharmacy for internal use : supplies hospitalized patients, manages and controls medicines, prepares and dispenses them, and may manage sterile medical devices and experimental medicines

★ Must-know

📌 A generic medicine has the same active-ingredient composition as the reference specialty and must demonstrate bioequivalence, whereas a me-too medicine has a modified but similar structure.

Further detail

• A pharmaceutical establishment manufactures and wholesales medicines under the responsibility of a pharmacist responsible for compliance with the Code de la Santé Publique.

💡 Memory Hook

Reference product → generic → magistral, officinal, hospital preparation

📖 3. Drug Discovery Strategy

🔑 Key Concepts & Definitions

• Hit : a first molecule with promising biological activity that is not sufficiently optimized to become a medicine
• Lead : an optimized molecule presenting an improved biological-activity profile and suitable for progression toward preclinical development

📝 Essential Points

• 🔄 Drug discovery proceeds through these stages:

  1. target selection
  2. bioactive-molecule design
  3. compound-library synthesis
  4. structure-activity analysis
  5. structural optimization of a hit

• Drug targets include:

  • receptors
  • enzymes
  • transport molecules
  • ion channels
  • idiosyncratic targets
  • nucleic acids

📌 In vitro experiments are performed outside a living organism, whereas in vivo experiments are performed in a living organism.

💡 Memory Hook

Target → design → library → screening → optimization

📖 4. Molecular Modeling Applications

🔑 Key Concepts & Definitions

• Molecular modeling : investigates molecular structures and properties using computational chemistry and graphical visualization to produce a plausible three-dimensional representation under defined conditions
• Pharmacophore : a spatial arrangement of chemical functions necessary for a molecule's biological activity

★ Must-know

• Homology modeling searches for a structurally known sequence analogue, aligns the sequences, builds a model by replacing different amino acids, then performs energy minimization and model validation.

Further detail

• UniProt is a database of protein or nucleic-acid sequences, whereas the Protein Data Bank is a database of three-dimensional structures.

• The seven pharmacophore functions are:

  • aromatic hydrophobic function
  • aliphatic hydrophobic function
  • positive charge
  • negative charge
  • ionizable group
  • hydrogen-bond donor
  • hydrogen-bond acceptor

💡 Memory Hook

Receptor-based modeling starts from the target, whereas receptor-free modeling starts from molecular structure.

📖 5. Me-too Drugs and NSAIDs

🔑 Key Concepts & Definitions

• Me-too drug : a new active pharmaceutical ingredient structurally close to an original medicine, acting through a similar mechanism but differing sufficiently in structure to be patentable

★ Must-know

• Salicylic acid, the lead of the arylcarboxylic-acid series, contains a benzene ring, a carboxylic-acid function, and a hydroxyl function.

Further detail

• The common international nonproprietary-name suffixes -olol and -azepam group beta-blockers and benzodiazepines, respectively.

• To develop a me-too, an industrial company monitors competitors' patents, synthesizes uncovered analogues, selects one using preclinical studies, files a patent, conducts clinical studies, requests marketing authorization, and markets the product.

• Acetylsalicylic acid, or aspirin, is obtained by adding acetic acid to the hydroxyl group of salicylic acid through an ester bond.

💡 Memory Hook

A generic is identical to the reference product, whereas a me-too is structurally similar but distinct.

📖 6. Clinical Drug Development

★ Must-know

• Drug research and development lasts approximately 10 years, costs more than one billion euros overall, and is protected by a patent lasting 20 years.

• 🔄 Drug development includes:

  1. in vitro research and development
  2. in vivo preclinical development
  3. clinical development in humans
  4. marketing authorization

Further detail

• Preclinical development costs approximately 10 to 20 million euros, whereas the early preclinical stage described in the course costs approximately 1.5 million euros and has 90% failures.

• After identification of a lead, galenic, pharmacokinetic, pharmacodynamic, and toxicological studies are performed to prepare the medicine and establish patient-safety rules.

💡 Memory Hook

Discovery → preclinical → clinical phases → marketing authorization

📖 7. Clinical Trial Phases

★ Must-know

• Clinical development progresses from phase I to phase IV, with progressively larger numbers of subjects, from fewer than 100 in phase I to several thousand in phase III.

• Phase I studies the maximum tolerated dose, pharmacokinetics, and pharmacodynamics when possible in fewer than 100 healthy volunteers.

• Phase II evaluates potential efficacy and toxicity, the dose-effect relationship, and the optimal dose in fewer than 500 volunteer patients.

• Phase III evaluates the benefit-risk ratio, defines the indication and special populations, and can support marketing authorization in fewer than 5000 ill patients.

Further detail

• Phase IV occurs after marketing and studies comparison with existing treatments, usefulness, pharmacoeconomics, tolerance, and marketing, only within the indication defined in phase III.

💡 Memory Hook

Phase I tolerability → Phase II dose → Phase III benefit-risk → Phase IV real-world use

📖 8. Pharmacokinetic Pathway

★ Must-know

📌 Pharmacokinetics describes what the organism does to the medicine through the dose-concentration relationship, whereas pharmacodynamics describes what the medicine does to the organism through the concentration-effect relationship.

• The ADME sequence comprises absorption, distribution, metabolism, and elimination.

📌 Passive diffusion follows a concentration gradient, uses no energy or transporter, and is not saturable, whereas facilitated diffusion uses saturable transporters and can involve competition between medicines.

• Distribution separates the active free fraction from the protein-bound reserve fraction, whose weak reversible binding can compete and is reduced during hypoalbuminemia.

• Drug metabolism mainly occurs in the liver and includes phase I functionalization by oxidation, reduction, or hydrolysis followed by phase II conjugation with endogenous polar molecules.

Further detail

• Active transport moves molecules against their concentration gradient through influx proteins such as OAT/OCT or efflux proteins such as P-glycoprotein and MRP.

💡 Memory Hook

ADME: Absorption, Distribution, Metabolism, Elimination.

📖 9. Drug Quality Control

🔑 Key Concepts & Definitions

• Good Manufacturing Practices : OMS — quality-assurance elements ensuring that products are manufactured and controlled uniformly according to standards appropriate to their use and specified in the marketing authorization

★ Must-know

• Medicine quality requires quality, safety, and efficacy, which are assessed through quantitative and qualitative analytical studies based on physicochemical methods.

• The World Health Organization acts internationally, the Council of Europe acts at the European level through the European Pharmacopoeia, and the ANSM applies the framework nationally in France.

📌 Analytical controls qualify what is present, quantify how much is present, identify substances, and detect impurities or related substances that should be absent or below defined limits.

Further detail

• European Pharmacopoeia monographs cover:
  • active ingredients
  • excipients
  • reagents
  • pharmaceutical forms
  • containers
  • analytical methods

💡 Memory Hook

Raw materials → formulation → packaging → finished-product control

📖 10. Dosage Forms and Administration

🔑 Key Concepts & Definitions

• Galenic form : the concrete pharmaceutical appearance of a medicine, such as a tablet, eye drop, gel, capsule, lotion, patch, or ointment

★ Must-know

• The main parenteral routes are:
  • intravenous
  • intramuscular
  • subcutaneous
  • intradermal

Further detail

• Galenic forms can be classified by physical appearance as solid, liquid, semisolid, or gaseous, or by administration route as oral, parenteral, or cutaneous.

• A syrup is an aqueous preparation with a sweet taste and viscous consistency, containing at least 45% m/m sucrose or another specified polyol or sweetener.

• An emulsion disperses liquid globules in another immiscible liquid, with either a lipophilic phase in a hydrophilic phase or a hydrophilic phase in a lipophilic phase.

• Gastro-resistant tablets resist gastric juice and release their active substances in intestinal juice.

💡 Memory Hook

Oral administration uses the digestive route, whereas parenteral administration crosses the skin.

📖 11. Prescription Rules

★ Must-know

• Prescribers include physicians and, within their scope of practice, midwives, dental surgeons, and physiotherapists for certain medical devices; since 2019, pharmacists can dispense and prescribe certain vaccines but generally do not prescribe medicines.

📌 Prescribing should follow the marketing authorization and the Summary of Product Characteristics, account for benefit-risk, and use explicit information adapted to the patient's pathology, history, allergies, previous treatments, and expectations.

• An ordonnance must include the date, prescriber identification, patient identification, medicine name, form, dose, route, duration, renewal instruction, and the prescriber's signature immediately below the last line.

• The four types of ordonnance are:

  • simple ordonnance
  • secured ordonnance
  • two-zone ordonnance
  • exceptional-medicine ordonnance

📌 A hospital-prescription medicine must be prescribed in a health establishment but may be dispensed in the community, whereas a hospital-initial-prescription medicine may be renewed by any prescriber after the initial hospital prescription.

Further detail

• For a medicine reserved for certain specialists, the initial prescription is restricted to specialist physicians, but subsequent renewal may be performed by any physician when only the initial prescription is restricted.

💡 Memory Hook

Patient → medicine → dose → route → duration → signature

📊 Synthesis Tables

Clinical Development Phases

Prescription Categories