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Questions and Answers
Pinocytosis is a mechanism where drugs or particles are engulfed by a cell without the need for energy expenditure.
False
Pinocytosis plays a significant role in the transport of all types of drugs, including protein drugs.
False
Most orally administered medications are absorbed primarily by the stomach due to its larger surface area compared to the intestine.
False
The thicker mucus layer in the stomach compared to the duodenum and jejunum enhances drug absorption in the stomach.
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Paracellular transport is a mechanism that involves drug transport through cells' interior.
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Transcellular transport is a mechanism more suitable for nanomedicines compared to paracellular transport.
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Oral drug administration is the most favored route to target systemic diseases.
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The main limitations of oral drug administration include high solubility and high permeability of drugs.
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Using excipients, salts, and lipids can decrease the bioavailability of drugs.
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Micro/nano fabrication and nano-device strategies are not helpful in overcoming the limitations of oral drug administration.
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Oral drug administration is not suitable for targeting gastrointestinal tissues such as colorectal cancers or bowel diseases.
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Effective oral dosage forms can easily target specific disease tissues without causing systemic side effects.
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The Biopharmaceutics Classification System (BCS) differentiates drugs based on their color and taste.
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Drugs classified under BCS Class III have high solubility and high permeability.
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In oral drug delivery, the released drug dose must be in a solid form to enhance absorption.
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High aqueous solubility of drugs is not important for gastrointestinal (GI) absorption.
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Permeability refers to the diffusion of drugs across the basal membrane of enterocytes.
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The Biopharmaceutics Classification System (BCS) does not consider drug permeability in its classification.
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Surfactants can decrease the transport of hydrophilic drugs by altering their paracellular permeability.
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EDTA is a paracellular permeation enhancer that increases the permeability of drugs but does not affect the permeability of toxic molecules.
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Eu-DTPA is an example of a hydrophobic fluorophore.
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Excipients can modulate the function of efflux transporters to decrease drug bioavailability.
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Cytochrome P450 3A4 is mainly found in the liver and has no role in drug metabolism.
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Co-administration of metabolism and efflux pump inhibitors can help overcome multidrug resistance.
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Stimuli-responsive materials can respond to only one type of stimulus.
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The most relevant stimuli for oral drug delivery are pH- and heat-sensitive systems.
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Acetalated dextran is a hydrophilic polymer.
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Multi-stimuli-responsive polymers in oral delivery only respond to one stimulus.
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Enzyme-sensitive systems are not relevant for oral drug delivery.
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Polymeric carriers are not used in oral dosage forms.
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Study Notes
Pinocytosis
- Pinocytosis is a mechanism of drug transport where drugs or particles are engulfed by a cell, requiring energy expenditure.
- This process involves the cell membrane invaginating, enclosing the drugs or particles, fusing again to form a vesicle, and detaching to move to the cell interior.
Barriers in Oral Drug Delivery
- Biological barriers: the epithelial lining of the intestines is a major barrier to drug absorption in the GI tract.
- Physicochemical barriers: low solubility, low permeability, and degradation (low stability) hinder oral drug delivery.
Oral Drug Administration and Its Limitations
- Low targeting: orally administered drugs travel through GI tissues, making it challenging to target specific disease tissues.
- Barriers in oral drug delivery: physicochemical barriers, including low solubility and permeability, and metabolic and biochemical barriers.
Biopharmaceutics Classification System (BCS)
- Class I: high solubility and high permeability.
- Class II: low solubility and high permeability.
- Class III: high solubility and low permeability.
- Class IV: low solubility and low permeability.
Strategies to Overcome Barriers
- Using excipients, salts, lipids, and polymers to increase solubility, permeability, and efficacy of drugs.
- Micro/nano fabrication and nano-device strategies to overcome limitations.
Oral Dosage Forms
- Co-crystals and coformers.
- Metabolism and efflux pump inhibitors to overcome multidrug resistance and increase oral bioavailability.
- Nano/micro-based oral dosage forms using stimuli-responsive materials.
- pH-responsive hydrogels and multi-stimuli-responsive polymers in NanoDDS.
Nano/Micro-Based Oral Dosage Forms
- Gastric retention time and GI pH vary between patients and organs, making multi-stimuli-responsive materials important.
- pH- and enzyme-sensitive systems are most relevant to oral drug delivery.
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Description
Learn about the limitations of oral drug administration, such as low solubility and permeability, and how excipients and nanotechnology can overcome these challenges to improve drug bioavailability and efficacy.
