IE 2: Formulation of Biopharmaceutical Drugs Part 1

In the formulation development process, what is in the product development phase?

• Discovery research

• Preclinical research

• Clinical trial application

• Phase I/II Clinical

• Phase II/III Clinical

• License Application

• Product

In the formulation development process, what is in the formulation development phase?

• Preformulation

  • Try to improve stability, solubility, BA, safety, efficacy of a biologic

• Development of drug substance

• Early stage formulation development

• Late stage formulation development

In the formulation development process, what is in the formulation used for development phase?

• Initial formulation

• Optimized formulation

• Commercial product

What is an API?

• Active pharmaceutical ingredient (main ingredient) in manufacturing a drug product

What is the description of API/drug substance?

• Type of protein, physico-chemical properties

• Ex: molecular weight, pL, hydrophobicity, solubility, post-translational modifications, pegylation, physical and chemical stability + concentration, available amount, purity

What is the description of clinical factors?

• Pt population (ex: age, concomitant med), self admin vs admin by professional, compatibility with infusion solution, indication (ex: one time application or chronical application)

What is the description of Route of admin?

• SQ, IV injection or infusion, IM, intravitreal, intra-articular, intradermal, pulmonal

What is the description of dosage form?

• Single- or multi dose, prefilled syringe, dual chamber cartridge, pen cartridge; liquid, lyophilize, frozen liquid, API concentration, injection volume, injection rate, controlled delivery/release

What is the description of primary packaging material?

• Glass, polymers, rubber, silicone oil, metals, leachable (antioxidants, plasticizers, etc)

What is the description of excipients?

• Pharmaceutical quality, safety record (for intended admin route and dose), manufacturer, tested for critical impurities, stability

What is the description of analytical methods?

• Characterization of API, stability-indicating assays, quality control assays

What are the stress factors and when are they encountered?

• Elevated temp/temp excursions: production (upstream and downstream processing); improper shipment; storage or handling deviations

• Freezing, freeze-thawing: storage of frozen (bulk) material; accidental freezing during storage or shipment; lyophilization

• Mechanical stress: production (pumping, stirring, filtration)

• Light: production; shipment; storage; handling

• Oxidative stress: production (exposure to oxygen); exposure to peroxide or metal ion impurities in excipients; shipment (cavitation)

• pH changes: production (downstream processing); freezing; formulation; dilution in infusion liquids; administration

• Interfaces: air-water interface; filters; primary packaging material; infusion bags and admin lines; particulate impurities

• X-ray: air freight transportation

What are some chemical instability factors?

• Deamidation

• Oxidation

• Proteolysis (hydrolysis)

• Disulfide shuffling

• Racemization

• Beta elimination

What are some physical instability issues?

• Conformational (proteins)

  • Unfolding

  • Misfolding

• Colloidal

  • Aggregation

  • Precipitation

• Adsorption

What is known about degradation reactions?

• Each degradation reaction can induce another one

• Multiple degradation processes occur at different rates, yielding numerous degradation products

In temperature as a stress factor, what are the anticipated instability types?

• Aggregation, conformational change, chemical change

In mechanical (shaking, stirring, freeze-thawing) as a stress factor, what are the anticipated instability types?

• Aggregation, adsorption, conformational changes

In oxidation (H2O2) as a stress factor, what are the anticipated instability types?

• Aggregation, conformation changes, chemical change

In humidity as a stress factor, what are the anticipated instability types?

• Aggregation, conformational changes, chemical changes

In primary packaging, what vials are used for their corresponding formulations? What is used for auto injections?

• 6 mL (6R) and 10 mL (10R) vial with corresponding stoppers for liquid and lyophilized formulations

• Auto-injections: prefilled syringe (PFS), single chamber cartridge (SCC), dual chamber cartridge (DCC), a pen device (pen)

What is needle size determined by?

• Gauge

• Length

What does a larger gauge number mean?

• The finer (smaller) the diameter of the needle’s bore

  • Higher gauge (G) → thinner needles are

  • Ex: 27 gauge needle finer than 13 gauge needle

What are common needle sizes?

• 16G 1&1/2 inch

• 18G 1&1/2 inch

• 20G 1 inch

In excipients, what do buffers do and examples?

• pH control, tonicity

• Histidine, phosphate, acetate, citrate, succinate

In excipients, what do salts do and examples?

• tonicity, stabilization, viscosity reduction

• Sodium chloride

In excipients, what do sugars/polyols do and examples?

• tonicity, stabilization, cryoprotection, lyoprotection, bulking agent, reconstitution improvement

• Sucrose, trehalose, mannitol, sorbitol

In excipients, what do surfactants do and examples?

• Adsorption prevention, solubilization, stabilization, reconstitution improvement

• Polysorbate 20/80, poloxamer 188

In excipients, what do amino acids do and examples?

• Stabilization, viscosity reduction, tonicity, pH control, bulking agent

• Arginine, glycine, histidine, lysine, proline

In excipients, what do anti-oxidants do and examples?

• Oxidation prevention

• Methionine, sodium edetate

In excipients, what do preservatives do and examples?

• Bacterial growth prevention

• M-cresol, benzyl alcohol, phenol

What helps solubility enhancement?

• Selection of the proper pH

• Ionic strength conditions

• Addition of AA or surfactants

What are surfactants for parenteral use?

• Polysorbate 20/80

• Poloxamer 188

• 2-hydroxypropyl-beta-cyclodextrin

What can adsorption cause an issue in?

• Aggregation of particles which causes stability issues

• Use surfactant to prevent this

How do you reduce aggregation in the bulk of a solution?

• Adding sugars (sucrose, above pH 6) or adding sugar alcohols (mannitol, sorbitol)

• Selection of a proper pH value and buffer components

• Maillard reaction: reaction between reducing sugars and proteins

What can have profound effects on the physical (aggregation) and chemical stability of proteins?

• BOTH the pH and the buffer species itself

What buffer systems are used in protein formulations? What solutions may NOT need a buffer?

• phosphate, citrate, histidine, succinate, glutamate, and acetate

• Highly concentrated protein solutions (protein concentration > 50 mg/ml) may not need a buffer

Which AA residues are readily oxidized? What can protect against oxidation? What can reduce oxidation?

• Methionine, cysteine, tryptophan, tyrosine, and histidine

• Replacement of oxygen by inert gases (ex: argon) in the vials can protect against oxidation

• Addition of antioxidants, such as methionine, can reduce oxidation

What are common preservatives used?

• Common preservatives: Phenol, meta-cresol, benzyl alcohol, and chlorobutanol

  • Ex of interaction: insulin and phenols (the preservative for insulin)

What are common isotonicity agents?

• Disaccharides, polyols, sodium chloride

What do cryoprotectants do?

• Protect protein during freezing or in the frozen state

• Replace water by forming hydrogen bonds with the protein

• Ex include sugars [sucrose (above pH 6), trehalose] and sugar alcohols (ex: mannitol, sorbitol)

What do lyoprotectants do?

• Protect the protein in the lyophilized state

• Replace water as a stabilizing agent by forming hydrogen bonds with the protein

• Form a glassy amorphous matrix keeping protein molecules separated from each other

• Ex include sugars (ex: sucrose, trehalose)

What should NOT be used in protection against freezing and drying

• Reducing sugars such as glucose and lactose should not be used

What is the rational of freeze-drying (removal of water) proteins?

• Protein formulations undergo chemical and physical degradation processes due to the presence of water in liquid protein (in aqueous media)

  • These formulations do not meet the preferred stability requirements (shelf life >2 years)

What is the freeze-drying steps?

• Freezing

• Primary drying

• Secondary drying

Switching from IV to IM/SC may do what?

• Switching from IV to IM or SC may expand the mean residence time for short half-life proteins

  • Impact on bioavailability (lower extent of absorption and slower rate of absorption)

What are some absorption variations in parenteral route of admin?

• Diseases (e.g., diabetes can cause insulin resistance through high
  tissue peptidase activity)

• Differences in the level of activity of the muscle at the injection site

• Massage and heat at the injection site

• The state of the tissue (e.g., the occurrence of pathological conditions)

Low molecular weight drugs are subject to what? What about high molecular weight?

• Low molecular weight drugs are passage through the membrane of capillary wall

  • 5-fluorodeoxyuridine (FUdR) is 256.2 Da so it is very small so the lymph recovery is low since it passes via capillary wall

  • Insulin has 5.2 kDa

• High molecular weight drugs cannot pass these membranes so lymphatic system is the place for the absorption for these drugs

  • rIFN-alpha 2a has MW of 19kDa so it is big so lymph recovery higher

  • Cytochrome C has 12.3 kDa

What is the oral route of admin?

• Pro: easy to access, proven track record with conventional meds, sustained/controlled release possible

• Con: negligible BA for proteins

What is the nasal route of admin?

• Pro: easily accessible, fast uptake, proven track record with conventional meds, probably lower proteolytic activity than in the GI tract, avoid 1st pass, spatial containment of absorption enhancers possible

• Cons: reproducibility (in particular pathological conditions), safety (ciliary movement), negligible BA for proteins

What is the pulmonary route of admin?

• Pro: relatively easy to access, fast uptake, proven track record with conventional meds, substantial fraction of insulin absorbs, lower protelytic activity than in GI, avoidance of 1st pass

• Con: reproducibility (in some conditions, smokers/nonsmokers), safety, presence of macrophages in lung with high affinity for particulates

What is the rectal route of admin?

• Pro: easily accessible, partial avoidance of hepatic 1st pass, probably lower proteolytic activity than in upper parts of GI, spatial containment of absorption enhancers possible, proven track record with conventional meds

• Con: negligible BA for proteins

What is the buccal route of admin?

• Pro: easily accessible, avoidance of 1st pass, lower proteolytic activity than in the lower parts of the GI tract, spatial containment of absorption enhancers possible, option to remove formulation if necessary

• Con: negligible BA of proteins, no proven track record yet

What is the transdermal route of admin?

• Pro: easily accessible, avoidance of 1st pass, removal of formulation if necessary is possible, spatial containment of absorption enhancers, proven track record with conventional meds, sustained/controlled release possible

• Con: negligible BA of proteins

What is the intravitreal route of admin? What are some examples?

• Pro: direct access to vitreous, delivery close to target site

• Con: not suitable for systemic effects

• Ex: Ranibizumab, Bevacizuman, Aflibercept (Ophthalmic)