Module 2: Dissolution Methods

<For now> Cards done using sum up slides

Where are drugs usually absorbed after oral administration?

Small intestine

What happens in the dissolution process?

Transfer of molecules from a solid state into a solution

Main function of the small intestine

Digestion, pH regulation and absorption

Why is the small intestine the primary site of nutrient and drug absorption?

Large surface area

Why do we use in-vitro models

Simple, cheap, robust and no ethical concerns

What properties are included in the BCS (Biopharmaceutics classification system)

Permeability and solubility

Is temperature important to consider when designing a dissolution experiment?

Yes

Is type of medium important to consider when designing a dissolution experiment?

Yes

Is volume important to consider when designing a dissolution experiment?

Yes

Do DDS properties need to be considered when designing a dissolution experiment?

Yes

What is the biphasic dissolution model?

Combining dissolution and absorption profiles

Why do we use pharmacopoeial dissolution models

Simple, cheap and robust

Why do we use intestinal and gastric biorelevant media?

To simulate physiological conditions in the gastrointestinal tract

Purpose of pharmacopoeial dissolution model

Measure how a drug dissolves over time

Purpose of biphasic dissolution model

Simulate how poorly water-soluble drugs dissolve in the GI tract and pass through the body

Choosing/designing the right in-vitro model

• physicochemical characteristics of the drug

• excipient characteristics

• physiological considerations

In-vitro model options

• Mechanical digestion

• Enzymatic ingestion

  • Intestinal

  • Gastro-intestinal

Dissolution testing considerations

• Temperature

• Dissolution medium

• Media change

• Volume (sink/non-sink conditions)

• Drug delivery system (DDS)

• Apparatus