Recording-2025-03-05T06:42:08.884Z

Dosage Forms of Medicines

• Medicines are available in various forms.

• The tablet is the most common dosage form.

Tablet Administration and Dissolution

• When a tablet is swallowed:

  • It first disintegrates in the stomach.

  • Dissolution occurs thereafter.

• Dissolution defined:

  • Transition of drug molecules from a solid state (tablet particles) to a solution state (dissolved in gastric fluid).

• Importance of gastric acidity:

  • The stomach’s highly acidic environment can lead to breakdown of some drug molecules.

Drug Absorption in the Small Intestine

• After gastric processing:

  • Dissolved drug molecules are passed into the small intestine.

  • Here, drug molecules are absorbed across the epithelial layer.

• Purpose of absorption:

  • Allows drugs to enter the bloodstream and circulate throughout the body to reach their target sites.

Factors Influencing Drug Absorption

• The efficiency of drug absorption is influenced by several key factors:

  • Dissolution: Rate at which the drug dissolves.

  • Solubility: Ability of the drug to dissolve in fluids.

  • Stability: Drug's ability to maintain its chemical integrity in the gastrointestinal environment.

  • Permeability: Ability of the drug to cross the intestinal barrier into the bloodstream.

• These factors are determined by:

  • Physical properties of the tablet.

  • Chemical properties of the drug molecule.

  • Physiological factors related to the patient’s gastrointestinal system.

Importance of Understanding Drug Absorption

• Grasping the drug absorption process is crucial:

  • Ensures efficacy of medicines administered via the oral route.