Modified drug release dosage forms: These dosage forms are designed to release drugs in a...
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Transcript of Modified drug release dosage forms: These dosage forms are designed to release drugs in a...
FIRST ORDER RELEASE
APPROXIMATION
Introduction Modified drug release dosage
forms:These dosage forms are designed
to release drugs in a controlled manner, at a predetermined rate, duration and location to achieve and maintain optimum therapeutic levels of drug.
terms used to describe modified release
dosage forms sustained release (SR) prolonged action controlled release (CR) extended release (ER) modified release timed release long acting
drugs suited for modified release
productsDrugs that have neither very
slow nor very fast rates of absorption and excretion
Drugs that have uniform absorption in the GI tract
Drugs that have small doses (less than 500mg)
Drugs with a wide therapeutic index
Drugs for chronic disease conditions
Drug release kinetics
• First-order kinetics
• Zero-order kinetics
ZERO-OREDER KINETICS
• The process that takes place at a
constant rate independent of drug
concentration involved in process
• Rate of process cannot be increased even the drug concentration is increased
First-order kinetics
• The process that is directly proportional to the drug concentration involved in
process • Rate of process
increases linearly with increase in drug concentration
First order release approximation
• Biopharmaceutical factors
• Dosage form selection
Biopharmaceutical factors
• Stomach• Small intestine• Large intestine
Stomach
• Dissolution of drug in stomach may be affected by presence or absence of food
Small intestine• Basic pH, large surface
area and presence of bacterial flora may affect the absorption of drug
Large intestine• Not much is known about drug
absorption in this area although unabsorbed drug that reaches the area are metabolized by bacteria.
Dosage form selection
• To minimize risk of rapid stomach absorption
• To release the drug immediately
Group members
Ambreen Ghulam Nabi 2910130
Ishima Naiyarain Zafar 2910171
Komal Sandhu 2910176
Maryam Musharraf 2910185
Sobana Baree 2910233
Syeda Zehra Jabeen Naqvi 2910245
Syeda Midhat Fatima 2910246
Samia Yaqoob 29478