mechanism of absorption

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ABSORPTION OF DRUGSShaik. Vaheeda rehmanDept of pharmacology

Welcome

Introduction of absorption.

Structure of the Cell Membrane.

Gastro intestinal absorption of drugs.

Mechanism of Drug absorption.CONTENTS

introduction

Introduction of AbsorptionDefinition :-The process of movement of unchanged drug from the site of administration to systemic circulation.

Anatomy and physiologyOf stomach

Anatomy and physiologyOf stomachWall of the stomach:-Muscle layerOuter layer(longitudinal fibres)Middle layer(circular fibres)Inner layer(oblique fibres)mucosa

Lumen of stomach

Nerve supplyPara sympathetic supply:Contraction of smooth muscleSecretion of digestive juicesSympathetic supply:Reduces smooth muscle contraction vagus nerve Reduces the glandular secretion

Blood supplyArterial supply:-Stomach- coeliac arterySmall intestine- superior mesenteric arteryLarge intestine- inferior mesenteric arteryVenous drainage:-Portal veinStomach- right gastroepiploic veinSmall intestine- superior mesenteric veinLarge intestine- inferior mesenteric vein

Cell membrane

Gastro intestinal absorption of drugs

Mechanism of drug absorption

Mechanism of action

Trans cellular absorptionPara cellular absorptionTransport in vesicles

Transcellular absorption:Passive diffusionCarrier mediated transportactive transportFaciliated transportCarrier mediated intestinal transportIonic/electrochemical diffusionIon pair transport

Paracellular transport:Pore transportTransport in vesiclesEndocytosis(phagocytosis, penocytosis)Exocytosistranscytosis

Difference between passive and active transport

Ion pair transport

Transport in vesicles

Pore transport

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