Non-Parenteral Routes for Drug Delivery: Oral Drug Delivery

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What is one of the advantages of the oral route for drug delivery?

Larger surface area of the GI compared to other transmucosal routes (correct)

Inability to use CR dosage forms to simplify dosing schedules

Limited self-administration and invasiveness

Reduced blood supply in the GI tract

Why is the specialized columnar epithelium of the GI tract conducive to drug absorption?

It allows for rapid absorption of drugs with appropriate physicochemical characteristics (correct)

It is highly resistant to drug absorption

It has a poor blood supply, leading to slow drug absorption

It lacks absorptive properties, making it unsuitable for drug absorption

How does the rich blood supply of the GI mucosa contribute to drug delivery?

It delays drug absorption due to reduced vascular surface

It ensures rapid drug absorption and onset of action (correct)

It leads to decreased drug effectiveness

It has no impact on drug absorption

Why does the oral route allow for improved compliance?

It enables self-administration and is noninvasive Signup and view all the answers

How do controlled-release (CR) dosage forms impact dosing schedules?

They can eliminate the need for frequent daily-dosage regimens Signup and view all the answers

What characteristic makes the oral route usually the safest and least expensive route for drug delivery?

It allows for self-administration and is noninvasive Signup and view all the answers

What is a significant benefit of the oral route for drug delivery?

Amenability to immediate release (IR) Signup and view all the answers

What is a function of the pancreatic enzymes in the small intestine?

Digestion of proteins, carbohydrates, fats, and nucleic acids Signup and view all the answers

What is a role of the GI mucus layer in oral drug delivery?

Acts as a physical barrier hindering drug diffusion to the absorbing surface Signup and view all the answers

What is a limiting factor for oral drug delivery associated with the P-Glycoprotein Efflux Pump?

Functions as an energy-dependent, drug efflux pump at the apical surface of cells Signup and view all the answers

What pH range is observed in the duodenum along the GI tract?

4 to 5 Signup and view all the answers

What is one of the roles of the pH of fluids along the GI tract in oral drug delivery?

Affecting the ionization and absorption properties of the drug Signup and view all the answers

Which enzyme is found in the stomach?

Pepsin Signup and view all the answers

What is one function of the GI mucus layer?

Hinders drug diffusion to the absorbing surface Signup and view all the answers

According to the Noyes-Whitney Rule, what is the fundamental principle for evaluation of the kinetics of drug release?

The mass transferred with respect to time by dissolution from the solid particle of instantaneous surface Signup and view all the answers

What are the units in which the rate of dissolution dM/dt can be expressed for most solids?

g/(cm-2.s-1) Signup and view all the answers

In which conditions is the dissolution of the solid said to be occurring under 'sink' conditions?

When Ct is less than 15% of the saturated solubility Cs Signup and view all the answers

What is the effect of the prevailing concentration driving force (Cs - Ct) on the dissolution rate of the solid?

It has a negligible influence when Ct is less than 15% of Cs Signup and view all the answers

What was offered by Noyes and Whitney in 1897 as the fundamental principle for evaluation of the kinetics of drug release?

The Noyes-Whitney Rule Signup and view all the answers

What does M represent in the Noyes-Whitney equation: M = (S)(Cs - Ct)(dM/dt)?

The mass transferred with respect to time by dissolution from the solid particle Signup and view all the answers

What is the ideal condition for the surface in the Noyes-Whitney equation?

A linear concentration gradient is confined to the layer of solution adhering to solid surface Signup and view all the answers

Which model assumes that the drug is dissolved uniformly from all surfaces of the particles?

Noyes-Whitney equation Signup and view all the answers

What relationship did Nernst and Brunner establish in their film theory?

$D = gSh$ Signup and view all the answers

What type of methods are used to investigate the kinetics of drug release from controlled release formulations?

Statistical methods, model dependent methods, model independent methods Signup and view all the answers

What does the Noyes-Whitney equation assume about the particles?

They have uniform drug dissolution from all surfaces Signup and view all the answers

Which equation represents the relationship between the constant and the diffusion coefficient in Nernst and Brunner's film theory?

$D = gSh$ Signup and view all the answers

Which category of kinetic models describes the overall release of drug from dosage forms?

Zero order, first order, Higuchi model Signup and view all the answers

What are the number of kinetic models described for overall drug release?

Three kinetic models Signup and view all the answers

What assumption did Noyes-Whitney Equation make about the dissolution process?

The dissolution process corresponds to a first order reaction. Signup and view all the answers