Connective Tissue II - Dr Muhammad Ali Rabbani - Medicose Academics
Feedback regulated drug delivery system.pptx
1. Name: Gaurav Anil Patil
M.Pharmacy(Department of
Pharmaceutics)
Feedback regulated drug
delivery system
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2. INDEX
• INTRODUCTION
• CLASSIFICTION OF FrDDS.
• BIOEROSION REGULATED DRUG DELIVERY SYSTEM
• BIORESPONSIVE DRUG ELIVERY SYSTEM
• SELF REGULATED DRUG DELIVERY SUSTEM
• REFERENCE
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3. Feedback regulated drug delivery system
• In this group of CrDDS , the release of drug molecules is activated by a
triggering agent, such as a biochemical substance, in the body via some
feedback mechanisms.
• The rate of drug release is regulated by the concentration of a triggering
agent in the CrDDS.
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5. Types of feedback regulated drug delivery
system
1. Bioerosion-regulated drug delivery system.
2. Bio responsive drug delivery system.
3. Self-regulating drug delivery system.
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6. Bioerosion regulated drug delivery system
• Bioerosion regulated delivery system works on the principle of degradation
of polymer by alteration in pH by immobilization of enzymes in the
microenvironment.
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7. Cross linking of
mixture of urease and
bovine serum albumin
This CrDDS consists of a drug-dispersed in the bio erodible matrix
prepared from a partially esterified copolymer of methyl vinyl ether and
maleic anhydride , which is coated with a layer of immobilized urease
Partially esterified
copolymer with dispersed
drug
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8. Urea Urease Ammonia
In the presence of urea, urease at the surface of the drug
delivery system metabolizes urea to form ammonia.
Increase in pH
Rapid degradation of polymer matrix
Release of drug
Mechanism
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10. Bio-responsive drug delivery system
In this CrDDS, the drug reservoir is enclosed by a bio-responsive
polymeric membrane whose permeability to drug molecules is
controlled by the concentration of a biochemical agent in the tissue
where the CrDDS is located.
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11. • A typical example of this Bio-responsive FrDDS is
glucose-triggered insulin delivery.
• Where,
Glucose + O2 Gluconic acid +H2O
Glucose oxidase
Insulin release
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12. • In which the insulin reservoir is encapsulated within a hydrogel
membrane containing suspended amine groups.
• In an alkaline solution, the amine groups exist at neutral state.
• Thus membrane is impermeable to insulin.
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13. Mechanism of action
This process triggers the protonation of amine groups to form
protonated groups, and the hydrogel membrane becomes swollen
which is permeable to insulin molecules.
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14. • In 1989, the system is developed by using
a porous cellulose membrane with
surface grafted poly acrylic acid as a pH
sensitive membrane
• In the absence of glucose the poly acrylic
acid chin are rode like, that reduces
porosity and supresses insulin release.
• When glucose oxidase converts glucose
to gluconic acid.
• Gluconic acid penetrates the poly acrylic
acid chain ,opening of pores enhance the
insulin release.
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15. Self regulating drug delivery system
This type of feedback-regulated CrDDS depends on a reversible and
competitive binding mechanism to activate and to regulate the release
of drug.
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Drug release
16. The complex of glycosylated insulin- concanavalin A, which is encapsulated
inside a polymer membrane. As glucose penetrates into the system, it
activates the release of glycosylated insulin from the complex for a
controlled release.
Mechanism
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