SN2 - Biotechnology and routes of administration Flashcards
What is a biopharmaceutical?
A protein or nucleic acid based pharmaceutical substance used for therapeutic or in vivo diagnostic purposes which are produced by means other than direct extraction from a native (non-engineered) biological source.
Describe 6 ways in which biopharmaceutical are different from conventional drugs
- Size - proteins are larger, cannot give orally- injected
- Complexity - post translational modifications (PEGylation)
- synthesis - cells genetically engineered (cell biology)
- purity
- stability
- immunogenicity - need to test for autoimmunity
What is PEGylation
you add polyethylene glycol to drugs to increase solubility, prolong biological half life and increase stability. PEG is a polymer that is even bigger than the protein itself (eg interferon)
New HEP C treatment
Alpha interferon prevents replication of Hep C - with PEGylation preventing rapid degradation.
How are biotech drugs manufactured - 7 steps
- expression of construct in host cell (transfection)
- generation of host cell bank (clone)
- production of recombinant protein (fermentator tanks)
- Purification (decontamination), low yield, high cost
- Analysis: biological activity/properties
- Pharmaceutical formulation - preservatives, buffers etc
- Storage - low temps, avoiding agitation.
Define non specific and neutralising antibodies
Non specific antibody; bind to any part of the drug
Neutralising antibodies: binds the target, diminishing / negating the effects of the drug altering its kinetics an dynamics
Biosimilar - define
biological product referring to an existing one and after time of patent expired (like generic)
What is epoetin alpha
recombinant erythropoetin
Define pharmacokinEtics and what it involves
What the BODY does to the drug: ADME Absorption Distribution Metabolism Elimination
Define PharmacoDynamics
What the DRUG DOES (to the body) - mechanism of action
What are the 3 processes that determine the active concentration of the drug
- entry into organism
- drug inactivation
- Exit
Considered as occurring at same time
Name 2 forms of drug in the body
Bound - protein
Free (active)
First pass effect - describe it.
Common to which route of administration?
hepatic metabolism of the agent when it is absorbed from the gut and delivered to liver via portal circulation. The greater the first pass effect, the less the agent will reach the systemic circulation. It is thus defined as pre-systemic. Oral disadvantage.
Absorbed mostly in the first part of intestine because of high surface area of microvilli.
Define absorption
when drugs get into the blood stream
Define bioavailability
How much of the drug gets into circulation
