Oral Drug Absorption: GI Tract Overview

Which scenario would MOST likely decrease the dissolution rate of a drug with limited aqueous solubility in the gastrointestinal (GI) tract?

A pharmaceutical scientist is formulating an ophthalmic suspension. Why might they choose to micronize the drug?

A patient consistently achieves subtherapeutic levels of a weak base drug. Knowing the drug's absorption is dissolution rate-limited, which strategy is LEAST likely to improve bioavailability?

A formulator is developing a topical cream containing a sparingly soluble drug. What is the MOST probable reason for choosing micronized drug particles?

Which statement BEST explains the mechanism by which salt formation enhances the dissolution rate of a weakly acidic drug?

Which of the following scenarios would LEAST favor the oral route of drug administration?

The gastric residence time of a drug is least likely to be affected by which of the following factors?

Naproxen sodium is preferred over naproxen for treating toothache due to its:

Which of the following is a primary function of the mucus layer in the gastrointestinal (GI) epithelium that directly impacts drug absorption?

A drug is formulated as a hydrochloride salt to improve its dissolution rate. What is the MOST likely property of the parent drug?

A scientist aims to formulate a sustained-release oral suspension. Which salt form would be most suitable?

How does Phase III of the migrating motor complex (MMC), also known as the 'housekeeper wave,' primarily influence drug absorption?

Which factor associated with food intake is MOST likely to decrease the rate of dissolution of a drug in the GI tract?

Which of the following scenarios would LEAST likely result in altered drug absorption in the gastrointestinal tract?

Consider a drug that is a weak base with a pKa of 6.0. Where would this drug be expected to exhibit the highest rate of passive diffusion across the GI membrane?

In the context of the Noyes-Whitney equation, if the effective surface area of a drug particle in contact with GI fluids is doubled, and all other parameters remain constant, the dissolution rate is:

A novel drug is found to be a substrate for P-glycoprotein (P-gp). How would you expect this to affect the oral bioavailability of the drug?

Which statement best characterizes the 'sink conditions' in the context of drug absorption via passive diffusion across the GI membrane?

Which scenario would MOST likely result in 'sink conditions' for a drug in the bloodstream?

A novel drug is found to be absorbed via active transport. Which characteristic would MOST likely be associated with its absorption?

A drug is absorbed into the body via facilitated diffusion. Which statement accurately describes this process?

Researchers are investigating a new method for delivering macromolecular drugs orally. Which mechanism would MOST likely be involved in the absorption of these large molecules?

A drug is known to be poorly lipid-soluble with a low molecular weight. By which pathway would this drug MOST likely be transported across the intestinal epithelium?

A drug's oral bioavailability is significantly reduced due to extensive efflux in the small intestine. Which protein is MOST likely responsible for this effect?

Which factor has the MOST significant impact on the transit time of materials through the small intestine?

How does the presence of food in the gastrointestinal (GI) tract affect drug absorption?

According to the Noyes-Whitney equation, if the diffusion coefficient of a sparingly soluble drug decreases in the presence of food, how is the dissolution rate MOST likely affected?

An increase in gastric and intestinal motility typically affects the dissolution rate of a sparingly soluble drug by influencing which factor described by the Noyes-Whitney equation?

Why is the amorphous form of a drug sometimes preferred over the crystalline form when formulating a medication, particularly for drugs with dissolution rate-limited absorption?

A pharmaceutical company is developing a new drug. During pre-formulation studies, they identify that the drug exhibits polymorphism. Which of the following considerations regarding polymorphism is MOST crucial for ensuring consistent drug performance and bioavailability?

During the crystallization process of a new drug, a scientist aims to produce a specific polymorph known for its enhanced bioavailability. Which factor is MOST influential in directing the formation of the desired polymorph?

A pharmaceutical formulation scientist is developing a suppository using cacao butter as the base. Why is it important to avoid complete melting of the stable polymorph of cacao butter during the manufacturing process?

For a drug that exhibits polymorphism, what is the primary rationale for a pharmaceutical company to choose the stable polymorph over a metastable polymorph in the formulation of a suspension?

A drug is known to exhibit polymorphism, with a significant difference in bioavailability between its polymorphs. Under what circumstances is this difference in bioavailability MOST likely to be clinically significant?

A pharmaceutical scientist discovers a new metastable polymorph of an existing drug with significantly enhanced solubility compared to the stable polymorph. What is the MOST important consideration when deciding whether to develop a drug product using this metastable polymorph?

A drug's bioavailability is observed to significantly decrease when administered with certain antidiarrheal medications. Which of the following mechanisms is most likely responsible for this interaction?

A researcher is investigating the use of cyclodextrins to improve the bioavailability of a poorly water-soluble drug. Which statement best describes the expected interaction and outcome?

A pharmaceutical scientist aims to enhance the stability of a drug that is prone to acid hydrolysis in the stomach. Which of the following strategies would be most effective?

Erythromycin, a drug known for its instability in the stomach, is being formulated for oral administration. Which approach would most effectively delay its release until it reaches the intestine?

In the development of a new oral suspension, a formulator must consider the solid-state properties of the drug. For which of the following dosage forms are the crystal properties and solid-state form of the drug most critical?

A drug substance can exist in multiple solid-state forms. Which of the following statements accurately describes the prevalence of these forms in pharmaceutical preparations?

Which of the following statements accurately differentiates crystalline and amorphous solid states?

A pharmaceutical scientist aims to produce an amorphous form of a drug to enhance its dissolution rate. Which method is most likely to yield an amorphous solid?

A research team is investigating methods to increase the amorphous content of a crystalline drug substance post-crystallization. Which technique is most likely to achieve this?

For a drug exhibiting dissolution rate-limited absorption, which solid-state form is expected to demonstrate substantially better absorption and bioavailability, and what is the underlying reason?

Oral Route Advantages

GI Mucus Role

Stomach Characteristics

Factors Affecting Absorption

Gastric Motility Patterns

Gastric Residence Time

Drug Absorption Barriers

Passive Diffusion

Dissolution Rate

Diffusion Coefficient (D)

Effective Surface Area (A)

Saturation Solubility (Cs)

Influence of Food

Particle Size Reduction

Weak Electrolyte Solubility

Salt Forms of Drugs

Factors Beyond Bioavailability

Influence of Agitation

Sink conditions

Active transport

Saturable mechanism

Facilitated diffusion

Endocytosis

Paracellular pathway

Drug efflux

Noyes-Whitney equation

Effects of food on drug absorption

Transporters for nutrients

Complexation

Adsorption

Chemical stability

Micellar solubilization

Enteric coating

Crystalline state

Amorphous state

Semi-crystalline materials

Milling

Bioavailability

Amorphous Drug Form

Crystalline Drug Form

Dissolution Rate Limited Absorption

Polymorphism

Stable vs. Metastable Polymorph

Impact of Polymorphs on Bioavailability

Crystallization Conditions for Polymorphs