Page 99 - Interactive Theoritical Notes of Bioharmaceutics and pharamcokinetics.docx compressed

PharmD clinical pharmacy program Level 3, Semester 2 Biopharmaceutics & Pharmacokinetics (PT608(

3. Gastric emptying

 Gastric emptying rate, gastric residence time or gastric emptying time is the time a

dosage form takes to traverse the stomach.

 Generally, drugs are better absorbed in the small intestine (because of the larger

surface area) than in the stomach; therefore, quicker stomach emptying will increase

drug absorption.

 Normal gastric residence times usually range between 5 min and 2 hrs, although

much longer times (over 12 hrs) have been recorded, particularly for large single

units.

❖ Factors that retard gastric emptying include:

1. Food especially fat diet

2. High viscosity or bulk diet

3. High concentration of electrolytes

4. Depression

5. Lying on the left side

6. Diseases like gastric ulcer, gastroenteritis, and gastrointestinal reflux.

7. Drugs like atropine, narcotic analgesics and chlorpromazine.

❖ Factors that promoted gastric emptying include:

1. Fasting or hunger
2. Alkaline buffer solution

3. Anxiety

4. Lying on the right side

5. Diseases like hyperthyroidism.

6. Drug like metaclopramide.

98