Advanced Formulations 1 Flashcards
Peptide drug vs protein drugs
-amino acids make peptides (>50aa) make proteins 2’
Basic structure of amino acid
-NH2 AMINO group
-COOH ACID group
-link w peptide bonds C-N
Semaglutide Ozempic
-synthetic
-31 aa
-weight loss
Peptide drug synthesis
- porous bead of NH2 functional groups
- coupling w aa w PG
- Deprotection (remove PG)
- Coupling w aa w PG
- Deprotection
- Cleavage (remove bead) or more cylcles
Problems w peptide drug synthesis
-coupling yields need to be very high for long synthesis
-yields for consecutive reactions need to be multiplied
Linear yield math
-if 80% for 5 aa
-0.8^5 = 0.328 = 32.8% overall
convergent synthesis yield math
-yield of just one of them but steps are going on at the same time
Yield of linear peptide 31 aa with 90% yield each step
-(0.9)^31 = 0.038 = 3.8%
-very low
protein size
greater than 40 aa
Can biologics be compounded?
-NO
-too fragile
-denaturation, aggregation
Protein drugs
-BIG >1000aa
-too hard to synthesize in lab
-v complex v fragile
How are protein drugs produced?
-100-1000L
-pilot plant
-probes for pH, dissolved O2, temp, pressure, biomass, carbon source
Basics of cloning/expression
-gene encoding protein drugs
-replication origin
-ampicillin resistance
-plasmid
Protein drug biosynthesis
-cloning?
-ribosomal synthesis
-post-trans mods
Bacteria expression systems
-no glycosylation
-endotoxins
Chinese hamster ovary
-expensive, susceptible to contamination w human pathogens/oncogenes
-best for antibody protection
Post translational modifications
-glycosylation adding extra sugars to the drug
-small differences can cause immune response
-careful process analytical tech to prove similarity of batched
Gold standard to analyze protein drugs biosimilarity
-HPLC + mass spectrometry
-endoglycosidase cuts of glycosylation
disulfide bonds can be unstable
lead to degradation
Conditions that can lead to protein degradation
-temp
-agitation
-pH
-deamidation
-oxidation
-photostability
Agitation leads to
-inc contact w surfaces
=aggregation
-do NOT shake
Freezing leads to
-ice crystals
=more concentrated mAb solution
=aggregation
Aggregation onset
-can happen hours after shaking
Biologics stabilization
-excipients
-interact w surface of protein
-excluded: repell from protein raise energy
-bound: lower energy
Unfolded proteins
-higher Gibbs free enrgy
-large surface area
-more unstable
preferentially excluded excipients
-repelled from protein surface
-raise energy
-destabilizer
preferentially bound excipients
-bind to protein surface
-lower energy
-stabilize
Salt concentration effect on protein stability
-effect can be dif for dif proteins
-unpreditable
-NEVER compound biologics
Nature can store proteins
-very long time inside of sugar glass
-Trehalose
-old wise shrimp
Sugar glass
-Trehalose, water, protein
-slow degradation bc high viscosity
-frozen out motions = stability
-biomimicry for storage of biologics
Blincyto
-reconstitute bc has trehalose for stability
Derivatization
-hydrophobic tail binds albumin
=inc half life
-levemir and ozempic (7day half life)
Considerations
-potency: nasal and pulmonary routes only for high potent drugs bc limited capacity
-variability: high
-safety
-cost
Oral semaglutide
-qd
-fasting required
-low bioavailability 1%
-does not open tight junctions
key challenge w RNA
-stability
-extra OH than DNA so less stable
-cleaved RNA can be toxic
siRNA
-30na
-can be synthesized chemically
-structure mods to inc half life
Longer RNAs synthesized by
-transciption enzymes
-outside of cell
-more controllable
-isolate enzymes
Modification of nucleotides
-replace w Me
-reduce immune reaction to mRNA
-inc protein production
siRNA length
-much shorter
-not transcribed to protein
Common RNA mods to ribose part
-me
-F
-OCCOC
-eliminate the nucleophilic 2-OH
=inc stability
Targeting ligands attached to the 3’ or 5’ ends of RNA can
-extend half-life of siRNAs
-acetyl group helps target the liver
siRNA product
-Leqvio
-injection every 3 to 6 MONTHS
-lowers cholesterol levels
-siRNA is very modified
