Stability of biologies Flashcards
What are biologies?
thoes are pharmaceutical products obtained diretly from living organism.
Examples of biologicals
Blood plasma products, vaccines
antivenoms
Why are biologies stored at low temperature?
Because there are more labile
is there any difference regarding the climatic zones?
For cold or frozen product there is no different
where does the activity of biologies comes from
from protein
structures of protein
covalently bounded primary structure
folder conformation: secondary and tertiary structure
What happend when there is a change in the conformation?
the protein will be in the denatured state, resultsing to loss of biological activity
Common bioassay
ELISA and immunblot methods
Method for the distribution of proteins
size-exclusion HPLC, SDS-Page
How can protein instabilities be categorized
Aggregation, deamidation, denaturation and oxidation
How can the proteine instability be divided
Chemical and pysical instabilities
What are chemical instabilities?
break or cvalent bonds, resulting in new chemical enthities
it is possibe to clearly discern the different instability (chemical and physical)
no, not always possible
Which amino acids preperably undergo oxidation and deamidation reactions?
Cysteine, histidine and tyrosine for oxidation
Glutamate
What does deamidation means?
Removal of the amino acid and converted to ammonia, which whoes toxic activity
What does physical instability means?
Changes its pyhsical state without any change in the chemical composition
Example of pyhsical change
Aggregation and precipitation and denaturation
How is the conformational stabiliy achieved?
optimization of the structural stability of the protein by maximinzing the gibbs energy
How can the gibbs energies be measured?
Differential scanning calorimetry (DSC) and isothermal chemical denaturation (ICD)
What causes aggregation in protein ?
incorrect folding druing protein expression.
what is the most influential factor in modulating aggregation?
the conformational stability
How are biologics administered?
parenterally
What are the requirements for parenteral products?
Sterile, free from visable particles,
How can the conformation stabilization achieved in aquaous solution?
By applying sugar or polyol ,this are osmoytes which increases the conformational stability to proteins
Also salts
Which sugars should be avoided here?
What know reaction can occur
Sugras with protines reactions (lactse, reduced surgers). there will covalently bond to the sugar and so lose of the effcient
How can proteins be conformational stabilization?
by ligand inding to the native state
by ions
by drying
Stabilization by drying?
lyophilization
Stabilization of proteins by ions?
adding of salts to protein solution, specific interactions (binding of cations or anions directly to the protein
Stabilization of proteins by ligand binding
ligands which bind selectively to the naive state resulsting in net stabilization. excipients (including surfactants
what could happend during freezing?
cold denaturation could occure, prevention by adding non-ionic surfactants (polysorbate 20 or 80)
improvement of protein stability during freezedrying
plasticizers (water, glycerol or sorbitol)
buclking agents such as mannitol or glycine
what are the relevant ICH guidlines?
ICH Q1 A(R2) for general requirements
ICH Q5C guideline for additional consideration
ICH Q6B specification for boilogics
ICH Q5E for biotechological/biological products
does the guidlines QC5 cover antibiotics, heparins or vitamine
No
for what can the ICH Q1 staibility guidlines used for?
generally applicable to biologics, good starting place for designing stabiity protocols
For how many batches should stability date be provided (drug substance)
at least three batches, representative of the manufacturing scale of production
stability study of the drug product
at least three batches of final container prouct
What is a stability-indicating profile?
it should assure that change in identity, purity and potency of the product will be detected
Purity and molecular characterization method?
SDS-page, western blots
what are other product characteristics?
Viscual appearance, sterility tessting, additivies and container/closure
What is a biosimilar?
is a biological medicine highly similar to another already approved biological medicine
interms of structure, biological activity and efficacy, saftey and immuogenicity profile
What is necessary for the demonstration of bioequivalence
that will be for generic products, pharmacological studies
Why are BE-study not suitbale for biosimilar?
Because of their different pharmacokinetics and stability of the biosilmilar
What studies have to be conducted for biosimilar?
clinical studies, to check the efficacy, phase 3 studies
According to which criteria is the reference product selected?
nterms of structure, biological activity and efficacy, saftey and immuogenicity profile
aim of conformational studies
identiying conditions that maximize the structural stability of the native sate and prevent aggrgation
Biologics exist in equilibrium between
native, partially denaturated and denaturated conformational states
