krushna bagul MOA MPharm second year pptx

Suitable for PG students

1. PRESENTED BY Mr. Bagul Krushna D. PRN : 2402588214817001 Unser the guidance of Mrs. Vaibhav Changedya ( M.Pharm , Phd ) Subject : Advance Biopharmaceutics Shri Sai College of Pharmacy , Khandala (2024-2025) Mechanism of drug absorption, factor affecting drug absorption, pH preparation THory of drug absorption

2. Definition of drug absorption Importance in pharmacokinetics Overview of presentation contents Definition of drug absorption Importance in pharmacokinetics Overview of presentation contents Introduction

3. Passive diffusion Facilitated diffusion Active transport Endocytosis/Pinocytosis Mechanism of Drug Absorption

4. Passive Diffusion Most common mechanism No energyrequired Follows concentration gradient ( High→Low ) Lipophilic and small drugs favored Passive Diffusion

5. Active Transport Uses carrier proteins + energy (ATP) Moves drugs against concentration gradient Saturable and selective Example: absorption of levodopa via amino acid transporter Active Transport

6. Endocytosis and Pinocytosis Rare for drugs Endocytosis: for large molecules (e.g., vitamin B12) Pinocytosis: non-specific fluid uptake Endocytosis and Pinocytosis

7. Facilitated DiffusionUses carrier proteins No energy required Saturable and selective Follows concentration gradient Facilitated Diffusion

8. Drug solubility Particle size Lipophilicity Ionization Biological Factors: Blood flow Surface area (e.g., small intestine) GI Ph EnzymesSlide Factors Affecting Drug AbsorptionPhysicochemical Properties:

9. Disintegration and dissolution rate Use of excipients (disintegrants, solubilizers) Formulation and Dosage Factors Drug formulation (tablet, capsule, suspension)

10. Intestinal motility Presence of food Interaction with other drugs Gastrointestinal FactorsGastric emptying time

11. pH Partition Theory Describes how drug absorption depends on: Drug ionization state pH of absorption site Drug's pKa pH Partition Theory

12. Lipid membrane Unionized form crossing membrane Ionized form remaining in aqueous phase pH Partition Theory Diagram

13. Weak acid (aspirin) absorbed better in stomach (pH ~1-3) Weak base (morphine) absorbed better in intestine (pH ~6-7.5) Practical Example

14. Mechanisms: passive, facilitated, active, endocytosis Factors: drug properties, formulation, biological environment pH partition theory explains ionization-based absorption Summary