Drug absorption

KELOMPOK 5 :

RANTI FADILAHRIA AFRIANIRIMA AZLINARIMA JAYANTI

RIDO FARNANDIRIVALDI ABBAS

RISNO HARDIANTORIYAN RAHMAN YUSUF

BIOPHARMACEUTICS

DR. MUSLIM SUARDI, MS.Apt

ABSORPTION OF DRUG

CONTENT• Introduction of absorption.• Gastro intestinal absorption of drugs.• Mechanism of Drug absorption.• Factors affecting drug absorption• Process absorption

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Introduction of Absorption

• Definition :The process of movement of unchanged drug from the site of administration to systemic circulation.

There always exist a correlation between the plasma concentration of a drug & the therapeutic response & thus, absorption can also be defined as the process of movement of unchanged drug from the site of administration to the site of measurement.

i.e., plasma

ABSORPTION

GT ABSORPTION DRUG

STOMACH The surface area for absorption of drugs is relatively small in

the stomach due to the absence of macrovilli & microvilli. Extent of drug absorption is affected by variation in the time

it takes the stomach to empty, i.e., how long the dosage form is able to reside in stomach.

Drugs which are acid labile must not be in contact with the acidic environment of the stomach.

Stomach emptying applies more to the solid dosage forms because the drug has to dissolve in the GI fluid before it is available for absorption.

Since solubility & dissolution rate of most drugs is a function of pH, it follows that, a delivery system carrying a drug that is predominantly absorbed from the stomach, must stay in the stomach for an extended period of time in order to assure maximum dissolution & therefore to extent of absorption

BIOLOGY FACTOR Penetration Of Drugs Through Gastro-intestinal Tract Penetration Of Drugs Through Blood Brain Barrier Penetration Of Drugs Through Placental Barrier Penetration Of Drugs Through Across The Skin Penetration Of Drugs Through The Mucous Membrane Of The Nose,

Throat, Trachea, Buccal Cavity, Lungs ,Vaginal And Rectal Surfaces

PHYSIOLOGICAL FACTORS: Gastrointestinal (Gi) Physiology Influence Of Drug Pka And Gi Ph On Drug Absorbtion Git Blood Flow Gastric Emptying Disease States

MECHANISM OF DRUG ABSORPTION

1) Passive diffusion2) Pore transport3) Carrier- mediated transport a) Facilitated diffusion

b) Active transport4) Ionic or Electrochemical diffusion5) Ion-pair transport6) Endocytosis

PHYSIO-CHEMICAL FACTORS

a. PHYCICAL FACTORSb. PHYSIO-CHEMICAL FACTORS

PHYCICAL FACTORS1. PARTICEL SIZE2. CRYSTAL FORM3. Solvates And Hydrates4. Complexation5. ADSORPTION6. DRUG STABILITY7. SALTS8. PRESENCE OF SURPACTAN9. DISSOLUTION

PHARMACEUTICAL FACTORS

• MEANS Absorption rate depends on the dosage • Form which is administred,ingredients used,

procedures• Used in formulation of dosage forms.• • The availability of the drug for absorption from the • dosage forms is in order.

• Solutions > Suspensions > capsules > Compressed • Tablets > Coated tablets.

SOLUTIONS

Shows maximum bioavailability and factors affecting Absorption from solution are as follows

1. Chemical stability of drug 2. Complexation: between drug and exipients of

formulation to increase the solubility, stability.3. Solubilization: incorporation of drug into micelles

to increase the solubility of drugs.4. Viscosity5. Type of solution: Whether aqueous or oily solution

That all from my group,Thank`s for your attention