Podcast
Questions and Answers
What term is used to describe the external shape of a crystal?
What term is used to describe the external shape of a crystal?
Which property can be influenced by crystal morphology or habit?
Which property can be influenced by crystal morphology or habit?
What term is used to describe the non-crystalline nature of materials?
What term is used to describe the non-crystalline nature of materials?
Which type of form is thermodynamically unstable due to its disordered structure?
Which type of form is thermodynamically unstable due to its disordered structure?
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What factor can influence the chemical stability of compounds with a low degree of crystallinity?
What factor can influence the chemical stability of compounds with a low degree of crystallinity?
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Which form of novobiocin was found to be more soluble and therapeutically active compared to the crystalline form?
Which form of novobiocin was found to be more soluble and therapeutically active compared to the crystalline form?
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What are pharmaceutical excipients?
What are pharmaceutical excipients?
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Why are pharmaceutical excipients included in drug products?
Why are pharmaceutical excipients included in drug products?
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Which of the following is NOT considered an excipient in a drug product?
Which of the following is NOT considered an excipient in a drug product?
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How are drug dosage forms classified based on route of administration?
How are drug dosage forms classified based on route of administration?
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Which type of dosage forms are absorbed through various epithelia and mucosa of the gastrointestinal tract?
Which type of dosage forms are absorbed through various epithelia and mucosa of the gastrointestinal tract?
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Which of the following is NOT an example of an oral dosage form?
Which of the following is NOT an example of an oral dosage form?
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Why are chelating agents used in preparing stable solutions of oxidizable drugs?
Why are chelating agents used in preparing stable solutions of oxidizable drugs?
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What effect can light have on oxidizable drugs in solution?
What effect can light have on oxidizable drugs in solution?
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How does racemization affect the stability of optically active compounds in solution?
How does racemization affect the stability of optically active compounds in solution?
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Why is it advised to keep oxidizable drugs in a cool place?
Why is it advised to keep oxidizable drugs in a cool place?
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What is the main characteristic of polymerization reactions?
What is the main characteristic of polymerization reactions?
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How can pH affect the stability of an oxidizable drug in solution?
How can pH affect the stability of an oxidizable drug in solution?
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What is polymorphism in the context of drug substances?
What is polymorphism in the context of drug substances?
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How do molecules arrange themselves in different polymorphs?
How do molecules arrange themselves in different polymorphs?
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What properties can vary between different polymorphic forms of drug substances?
What properties can vary between different polymorphic forms of drug substances?
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What is a solvate in the context of drug substances?
What is a solvate in the context of drug substances?
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Why is knowledge of polymorphism important at the pre-formulation stage?
Why is knowledge of polymorphism important at the pre-formulation stage?
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What is the general relationship between stability and polymorphism in drug substances?
What is the general relationship between stability and polymorphism in drug substances?
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Which factor limits the bioavailability of a drug for oral doses?
Which factor limits the bioavailability of a drug for oral doses?
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How is bioavailability calculated in pharmacokinetic studies?
How is bioavailability calculated in pharmacokinetic studies?
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Why are studies on bioavailability critical in drug research and development?
Why are studies on bioavailability critical in drug research and development?
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What path does a route of administration define in pharmacology and toxicology?
What path does a route of administration define in pharmacology and toxicology?
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What governs the choice of routes of drug administration?
What governs the choice of routes of drug administration?
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Why is oral administration commonly employed for drugs?
Why is oral administration commonly employed for drugs?
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Study Notes
Polymorphism
- Drug substances can exist in more than one crystalline form with different internal lattice arrangements
- Polymorphic forms can vary in properties such as solubility, hygroscopicity, diffusivity, dissolution rate, melting point, or stability
- Different polymorphic forms can influence therapeutic efficacy, stability, and manufacturing ability of a dosage form
- Solvates (pseudopolymorphs) contain entrapped solvent within their structure, affecting their properties
- Aqueous solubility of hydrate compounds can be significantly less than their anhydrous forms
- The most stable polymorph typically has the highest melting point and lowest solubility
Stability of Oxidizable Drugs
- Trace metals can catalyze oxidation reactions, affecting drug stability
- Light can also act as a catalyst for oxidation reactions
- Temperature, pH, and chelating agents can affect the stability of oxidizable drugs
- Packaging in light-resistant or opaque containers can help maintain stability
Racemization
- Racemization is the conversion of an optically active compound into its inactive, racemic mixture
- This can affect the pharmacological activity of the drug
- For example, levo-adrenaline is 15-20 times more active than dextro-adrenaline
Polymerization
- Polymerization is a continuous reaction between molecules, resulting in a polymer
- This can affect the flow properties of drug powders
- Methods such as angle of repose, flow through an orifice, compressibility index, and shear cell can measure flow properties
Crystallinity
- Crystallinity refers to the internal structure of a crystal
- Crystal morphology (habit) can influence properties such as powder flow properties, compaction, and stability
- A single internal structure can have multiple habits, depending on the environment during crystal growth
Amorphous Form
- Amorphous forms are non-crystalline, possessing no long-range order
- These forms are thermodynamically unstable and tend to revert to a more stable form
- Amorphous compounds can have a decrease in chemical stability
- Stable amorphous compounds can have better bioavailability, such as the stabilized amorphous form of novobiocin
Pharmaceutical Excipients
- Pharmaceutical excipients are inactive, non-medicinal substances intentionally included in a drug product
- Examples include bulking agents, disintegrants, stabilizers, solvents, lubricants, binders, and preservatives
- Excipients ensure the drug product is acceptable to regulatory authorities and patients in terms of manufacturability, appearance, and therapeutic efficacy
Classification of Dosage Forms
- Dosage forms can be classified based on the method or route of administration or physical form
- Classification based on route of administration includes oral, parenteral, topical, and other routes
Bioavailability and Pharmacokinetics
- Bioavailability is determined by measuring pharmacokinetics in subjects following intravenous doses for reference and the intending dosing route
- Bioavailability is calculated as the ratio of the dose-normalized AUCs from the extravascular and intravenous routes
- Bioavailability may differ between species, making these studies critical in preclinical and clinical stages of drug research and development
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Description
Learn about pharmaceutical excipients, which are inactive substances intentionally included in drug products for various pharmaceutical purposes during manufacture, storage, or use. Explore the role of excipients alongside the Active Pharmaceutical Ingredient (API) in ensuring the effectiveness and safety of medications.
