Physical Pharmacy Lecture 10: Adsorption

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What is the effect of additives on the properties of plastics?

They may have a pronounced effect on the sorption characteristics (correct)

They always make the plastics stronger

They have no effect

They reduce the sorption characteristics

What happens to the sorption of sorbic acid in aqueous solution by cellulose acetate and cellulose triacetate?

It shows pH dependence when the drug is in ionized form (correct)

It increases with pH

It is pH-independent

It decreases with pH

What is the condition for significant sorption of local anesthetics by polyamide and polyethylene?

When the drug is in ionized form

When the drug is in unionized form (correct)

When the pH is high

When the temperature is low

What kind of molecules adsorb at interfaces?

Macromolecules Signup and view all the answers

What is the purpose of adding albumin to prevent insulin adsorption?

To occupy the surface and reduce insulin adsorption Signup and view all the answers

What is the effect of adsorption on insulin administration?

It reduces the amount of insulin delivered Signup and view all the answers

What is the problem with using adsorbents to remove toxic substances from the gut?

They are non-specific and can adsorb nutrients, drugs, and enzymes Signup and view all the answers

What can be a consequence of administering adsorbents with drugs?

Decreased absorption of the drug Signup and view all the answers

What is the primary difference between adsorption and absorption?

Adsorption is a surface effect, whereas absorption involves penetration. Signup and view all the answers

What is the term used to describe the process of both adsorption and absorption?

Sorption Signup and view all the answers

What type of bond is involved in chemical adsorption?

Strong chemical bonds Signup and view all the answers

What is the term used to describe the reverse process of adsorption?

Desorption Signup and view all the answers

What is the primary factor that affects the solubility of an adsorbate?

Solubility of the adsorbate Signup and view all the answers

What is an example of a process that involves both physical and chemical adsorption?

Adsorption of toxins in the stomach by attapulgite and kaolin Signup and view all the answers

What is the characteristic of physical adsorption?

Not very specific and reversible Signup and view all the answers

What is the term used to describe the binding of an adsorbate to the surface of an adsorbent?

Adsorption Signup and view all the answers

What is the result of a drug being adsorbed when it reaches the absorption site?

A slow rate of absorption Signup and view all the answers

What is the effect of administering promazine with activated charcoal?

A reduced rate of absorption of promazine Signup and view all the answers

What is the effect of taking antacids with digoxin?

A decreased bioavailability of digoxin Signup and view all the answers

What is the effect of bentonite on the absorption of rifampicin?

A delayed absorption of rifampicin Signup and view all the answers

What is the effect of adsorption onto solids on preservatives?

A loss of activity of preservatives Signup and view all the answers

What is the effect of talc on the absorption of cyanocobalamin (Vitamin B12)?

A delayed absorption of cyanocobalamin (Vitamin B12) Signup and view all the answers

What is the effect of plastic tubes and connections on certain drugs?

A significant loss of certain drugs Signup and view all the answers

Which of the following drugs is not affected by adsorption onto plastic?

Aspirin Signup and view all the answers

What effect does increased temperature have on adsorption?

Decreases adsorption Signup and view all the answers

Why is adsorption important in the treatment of drug overdoses?

It removes the toxic drugs from the body Signup and view all the answers

How does magnesium trisilicate function as an antacid?

It adsorbs excess H+ acid in the stomach Signup and view all the answers

Which factor is NOT mentioned as influencing charcoal adsorption in treating poisonings?

Blood pressure Signup and view all the answers

What is the typical effectiveness of charcoal tablets compared to powdered charcoal?

Half as effective Signup and view all the answers

In the context of adsorption, what is the function of the 'universal antidote' used for poisoning?

Adsorbs poisons to reduce their effects Signup and view all the answers

Why might activated charcoal be less effective in vivo compared to in vitro for aspirin adsorption?

Influence of biological factors like GI motility and pH Signup and view all the answers

What role does adsorption play in the treatment of flatulence?

Adsorbs gases in the GIT Signup and view all the answers

What is essential for taste masking to be effective in vivo?

Desorption of the drug Signup and view all the answers

Which substrate showed reduced efficacy when diazepam was adsorbed onto it?

Microcrystalline cellulose (Avicel) Signup and view all the answers

What is a possible consequence of the adsorption of medicines onto container walls?

Reduced potency and stability Signup and view all the answers

What is the effect of Poloxamer 407 on the drug phenylbutazone?

Increases its dissolution rate Signup and view all the answers

What term is often used with plastic containers to describe the penetration of drugs into the polymer matrix?