Podcast
Questions and Answers
Poorly soluble drugs are typically absorbed quickly in the gastrointestinal tract.
Poorly soluble drugs are typically absorbed quickly in the gastrointestinal tract.
False
The surface charge of a particle can influence its interaction pattern with biological systems.
The surface charge of a particle can influence its interaction pattern with biological systems.
True
Downstream processing does not have any significant impact on the final dosage form of drug products.
Downstream processing does not have any significant impact on the final dosage form of drug products.
False
Eating food before taking an oral drug has no effect on its absorption.
Eating food before taking an oral drug has no effect on its absorption.
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The drug crystals used in approved nanoscale drugs are typically around 200 nm in size.
The drug crystals used in approved nanoscale drugs are typically around 200 nm in size.
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Receptor-mediated transport is not involved in the uptake of drug crystals at the nanoscale.
Receptor-mediated transport is not involved in the uptake of drug crystals at the nanoscale.
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There is no window of absorption for oral drugs, meaning they can be taken at any time.
There is no window of absorption for oral drugs, meaning they can be taken at any time.
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The D50 value represents the median particle size in a sample of drug crystals.
The D50 value represents the median particle size in a sample of drug crystals.
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Particle surface hydrophobicity does not play a role in determining the interaction pattern of particles with biological systems.
Particle surface hydrophobicity does not play a role in determining the interaction pattern of particles with biological systems.
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The hard and soft corona do not contribute to the modification of particle destiny in biological systems.
The hard and soft corona do not contribute to the modification of particle destiny in biological systems.
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Study Notes
Diffusion and Dissolution
- The diffusion constant is influenced by the thickness of the unstirred layer (h) and the mass of the substance (m).
- Saturation concentration is increased by higher dissolution pressure, as described by the Kelvin equation and the Freundlich-Ostwald equation.
Nanoparticles and Oral Absorption
- Conventional oral absorption of poorly soluble drugs is limited by the window of absorption, which is affected by the dissolution time and GI transit time.
- If the dissolution time is greater than the GI transit time, absorption is limited, but if the dissolution time is less than the GI transit time, absorption is enhanced.
- Examples of drugs that exhibit this behavior include Amoxicillin, Cefixime, Cefpodoxime, and Defuroxime axetil.
Challenges and Opportunities
- Food effects can impact oral uptake, and dosage forms require downstream processing, including nanoparticles, liposomes, and parenteral dosage forms.
- Stability and re-dispersibility are key challenges in downstream processing, and formulation-dependent parameters need to be optimized.
- Critical issues in nanoparticle development include reproducible production, sufficient specificity in targeting, and the dose to be delivered.
mRNA Delivery Systems
- mRNA delivery systems have large potential for diverse fields, including treatment, and benefit from different biological interactions.
- They support targeted delivery and have modified release profiles on shorter time frames.
- Precision Nanosystems has developed an mRNA delivery system for vaccination.
Drug Targeting
- After overcoming a barrier, distribution in the organism occurs through passive or active targeting.
- Active targeting involves ligands and receptors, and antibodies can be used for targeting.
- The fate of nanoparticles after uptake by ligands includes degradation by acidification, triggered release, and the proton sponge effect.
Production of Nanoparticles
- There are several approved drugs at the nanoscale, including D50 ~ 200 nm drug crystals.
- Production methods include grinding, precipitation, and coating, as well as controlled mixing time and nanosaar coating/complexation.
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Description
Test your knowledge on key factors affecting the oral absorption of poorly soluble drugs, such as diffusion constant, thickness of unstirred layer, mass, and Saturation concentration. Explore concepts like the Freundlich‐Ostwald equation, clearance time, nanoparticles, and examples of drugs with different dissolution and GI transit times.
