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Drug Delivery
The appropriate administration of drugs through various routes in the body for the purpose of improving health
Highly Interdisciplinary - Biology, Physiology, Materials, Engineering
Takes into consideration: Drug Physico-chemical properties, Body effects and interactions, Improvement of drug effect, Patient comfort and well being
The Magnitude of Drug Response
Dosage
Extent of Absorption
Distribution to the site
Rate/extent of Elimination

Partition Coefficient -The ratio of the concentrations of the solute in two immiscible or slightly miscible liquids when it is in equilibrium across the interface between them.
Bioavailability - The ability of a drug to be available to the body to be transported and carry out its engineered use, for example; to bind to a receptor or change the pH level of a certain region.

Drug Distribution (Vd) = Amount of drug in body / Concentration in Plasm

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Elimination of Drugs from the Body
Kidney - Filtration Secretion
Liver - Metabolism Secretion
Lungs - Exhalation
Others - Breast Milk, Sweat, Saliva
Elimination:
Zero Order- Constant rate of elimination irrespective of plasma concentration
First Order- Rate of elimination proportional to plasma concentration. Constant Fraction of drug elimination per unit time.
Rate of Elimination proportional to Amount
Rate of Elimination = K x Amount

Quantification of Drug Safety:
Therapeutic Index = TD50 or LD50
ED50

ED50- Median Effective Dose 50
TD50- Median Toxic Dose 50
LD50- Median Lethal Dose 50

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What are Polymers:
Polymers are organic (carbon-based) compounds where each molecule is a long-chain of covalently linked molecular units.
What are Monomers:
The basic chemical unit of a polymer (the individual beads to a necklace)
Macromolecules:
Refers to very large molecules. Polymers are generally composed of thousands of monomers, each polymer molecule is termed as macromolecules
Oligomers:
These are compounds having a few monomers joined together by covalent bonds (usually less than 50 repeating units)

Types of Polymers
Homopolymers - A-A-A-A-A-A
Random Copolymers - A-B-A-B-B-A
Alternating Copolymers - A-B-A-B-A-B
Block Copolymers - A-A-A-B-B-B
Graft Copolymers - A-A-A-A-B-B