Podcast
Questions and Answers
What is the primary characteristic of hydrophilic matrices in drug formulation?
What is the primary characteristic of hydrophilic matrices in drug formulation?
How do osmotic pumps regulate drug release?
How do osmotic pumps regulate drug release?
What role does tortuosity play in the release rate of drugs from an insoluble polymer matrix?
What role does tortuosity play in the release rate of drugs from an insoluble polymer matrix?
What commonly used material is an example of an insoluble polymer matrix?
What commonly used material is an example of an insoluble polymer matrix?
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Which of the following describes the mechanism of a membrane-controlled system?
Which of the following describes the mechanism of a membrane-controlled system?
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What is the primary purpose of the viscous gel structure formed in hydrophilic matrices?
What is the primary purpose of the viscous gel structure formed in hydrophilic matrices?
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What defines a multi-particulate system in drug formulation?
What defines a multi-particulate system in drug formulation?
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In polymer-coated formulations, what typically serves as the rate-controlling step?
In polymer-coated formulations, what typically serves as the rate-controlling step?
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Which of the following is a benefit of extended release formulations in pain management?
Which of the following is a benefit of extended release formulations in pain management?
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Which characteristic is crucial for the effectiveness of sublingual delivery of drugs?
Which characteristic is crucial for the effectiveness of sublingual delivery of drugs?
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What can interfere with the control of release and absorption in oral extended release formulations?
What can interfere with the control of release and absorption in oral extended release formulations?
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What is a primary advantage of intravenous drug administration for analgesia?
What is a primary advantage of intravenous drug administration for analgesia?
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Which factor limits the maximum period of an extended release product in the gastrointestinal tract?
Which factor limits the maximum period of an extended release product in the gastrointestinal tract?
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What risk is associated with an overdose of oral extended release medications?
What risk is associated with an overdose of oral extended release medications?
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What mechanism primarily governs drug absorption in transdermal delivery?
What mechanism primarily governs drug absorption in transdermal delivery?
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Which definition accurately describes extended release formulations?
Which definition accurately describes extended release formulations?
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What can potentially happen if a patient chews an extended release tablet?
What can potentially happen if a patient chews an extended release tablet?
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Which of the following describes an issue with formulating high drug load extended release tablets?
Which of the following describes an issue with formulating high drug load extended release tablets?
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What is a significant disadvantage of extended release formulations?
What is a significant disadvantage of extended release formulations?
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Which route of administration is least likely to be affected by first pass metabolism?
Which route of administration is least likely to be affected by first pass metabolism?
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What is a critical characteristic for an ideal extended release formulation?
What is a critical characteristic for an ideal extended release formulation?
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What materials are commonly used in a hydrophilic matrix for sustained drug release?
What materials are commonly used in a hydrophilic matrix for sustained drug release?
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How does oral controlled release enhance patient comfort?
How does oral controlled release enhance patient comfort?
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What is a key factor in the formulation of transdermal drugs for optimal absorption?
What is a key factor in the formulation of transdermal drugs for optimal absorption?
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Which dosage form uses water diffusion through a semi-permeable membrane for drug delivery?
Which dosage form uses water diffusion through a semi-permeable membrane for drug delivery?
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What key characteristic affects the absorption of low permeability drugs in extended release formulations?
What key characteristic affects the absorption of low permeability drugs in extended release formulations?
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What is the primary purpose of using buprenorphine in sublingual tablets?
What is the primary purpose of using buprenorphine in sublingual tablets?
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Why might some modified release products differ in effectiveness even if intended to be the same?
Why might some modified release products differ in effectiveness even if intended to be the same?
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What primary limitation does the oral route have regarding drug administration?
What primary limitation does the oral route have regarding drug administration?
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Which of the following leads to improved patient compliance with oral extended release formulations?
Which of the following leads to improved patient compliance with oral extended release formulations?
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Why is osmotic pumping used in drug delivery systems?
Why is osmotic pumping used in drug delivery systems?
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What role does lipid solubility play in the formulation of transdermal drugs?
What role does lipid solubility play in the formulation of transdermal drugs?
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What is a common characteristic of drugs used in buccal delivery?
What is a common characteristic of drugs used in buccal delivery?
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Study Notes
Drug Delivery for Analgesia: Opioid Focused
- The lecture focuses on drug delivery routes and formulations, especially for opioids used in analgesia.
- Delivery routes include oral, intravenous, transdermal, epidural, intrathecal, sublingual/buccal, nasal, and rectal.
Routes of Delivery/Dosage Forms for Analgesia
- Intravenous: Rapid delivery directly to the circulation, eliminating lag time between administration and action, leading to more predictable responses.
- Sublingual/Buccal: Absorption through oral mucosa (beneath the tongue) results in rapid onset and high blood levels. It bypasses first-pass metabolism.
Oral Controlled Release
- Modified-release formulations (extended-release) manage drug release, differing from immediate-release that delivers the entire dose upfront.
- Extended-release mechanisms include hydrophilic matrix, insoluble polymer/lipid matrix, membrane-controlled, and osmotic pumps.
Buccal Delivery
- The oral mucosa shows significant variations in the epithelial tissue's keratinization across different mouth regions.
- Regions with less keratinization, like sublingual, are more permeable.
Sublingual Tablets
- Used for transmucosal delivery.
- Small, porous, fast-disintegrating tablets placed under the tongue, offering a rapid onset of action.
Transdermal Delivery
- Drug diffusion from a reservoir through epidermis and dermis to the bloodstream.
- Absorption mainly occurs through lipid channels in the stratum corneum, ideal for small lipophilic molecules.
Ideal Properties for Transdermal Drugs
- Lipophilic drugs with low molecular weight tend to be better for transdermal delivery.
- Log P (partition coefficient) values between 1-4
- Molecular weights below 500
- Daily dose of 10-20mg/20cm²
Transdermal: Rate Limiting
- Two types: rate limiting membrane or matrix systems.
- Maintains sustained drug plasma profile for several days within the therapeutic window, eliminating dips in dose throughout the night, a common problem with oral tablets.
- Convenient and high patient compliance.
Oral Extended Release: Definitions
- Immediate release: Whole dose releases promptly.
- Modified release: Time course and/or location of release are adjusted for therapeutic benefit.
- Two types: Delayed release (e.g., enteric-coated) and extended-release (modified release).
Oral Extended Release: Meaning for Patients (1)
- Extended-release formulations keep drug levels within a therapeutic range for an extended period.
- One dose can maintain therapeutic levels overnight, improving sleep quality, and fewer doses are used. This contrasts with immediate-release requiring multiple doses.
- Reduces peak drug concentrations and the frequency of drug administration, reducing the risk of side effects.
Oral Extended Release: Meaning for Patients (2)
- Extended release can help prevent breakthrough symptoms and side effects if plasma levels fall below the required level.
- Reduces the overall drug dose administered throughout the treatment period, minimizing exposure to drugs.
Oral Extended Release: Meaning for Patients (3)
- Reduced dosing frequency benefits those with drugs that require frequent dosing.
- Increased patient compliance.
- Reduction in time spent on health services
Oral Extended Release: Limitations
- Physiological factors like gut pH, enzyme activity, and transit rate can impact drug release and absorption.
- Drug passage along the GI tract restricts the duration of therapeutic release from 30 minutes to 72 hours.
- Overdosing risk.
- Potential for toxicity if therapeutic index is narrow.
- Extended-release formulations may be larger, posing difficulties for swallowing.
Oral Extended Release: Additional Limitations
- Risk of poisoning from chewing/consuming the whole release tablet.
- Non-bioequivalence – similar intent drugs may differ in their therapeutic reaction
- Differences in drug release mechanism and time of release profile.
Factors Influencing the Design of Extended Release Oral Formulations
- Gastrointestinal (GI) physiology and absorption mechanisms.
- Rate of drug molecule movement through the GI tract affects the maximum duration of therapeutic release.
- Aqueous solubility and permeability of the drug—essential properties influencing dissolution and absorption.
Oral Extended Release: Key Formulations
- Hydrophilic matrix tablets, insoluble polymer matrices, membrane-controlled release, and osmotic pumps.
- Different types of excipients (e.g., polymers, salts, fillers) form the base of the formulations.
Oral Extended Release: Polymer Matrices / Drug Delivery Systems
- Insoluble polymer matrices (e.g., ethylcellulose, polymethacrylates) embed the drug, which diffuses through channels as the matrix degrades.
- Hydrophilic polymer matrices (e.g., hydroxypropyl methylcellulose, HPMC) swell in water, increasing the drug release rate.
Membrane Controlled System: Release Mechanism
- Water diffuses into the tablet, causing drug dissolution and diffusion through a polymer membrane.
- Release is mostly controlled by membrane erosion.
Osmotic Pumps
- Water enters the core of an osmotic pump (tablet), creating pressure to release the drug through a small hole in a semipermeable membrane.
- Drug release is dependent on membrane properties, solution/suspension properties, and the hole's diameter.
Why should patients not chew extended release formulations?
- Chewing can release the entire drug dose immediately, potentially causing adverse effects from rapid absorption and exceeding the safe therapeutic levels.
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Description
This quiz covers various drug delivery routes and formulations specifically for opioids used in analgesia. Topics include intravenous, sublingual, and controlled-release oral formulations, along with their mechanisms of action and advantages. Test your knowledge on effective pain management strategies through drug delivery methods.
