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Drug Manufacturing BIT 230 Walsh Chapter 3 Drug Manufacturing Most regulated of all manufacturing industries Highest safety and quality standards Parameters include: – – – – – Design and layout of facility Raw materials Process itself Personnel Regulatory framework Pharmacopeias Discussed before in other units and classes Martindale- not a standards book Gives information about drugs – – – – – Physiochemical properties Pharmacokinetics Uses and modes of administration Side effects Appropriate doses GMP guidelines Different publications world wide, but generally have similar information Go over everything from raw materials to the facility US guidelines issues publications called “Points to Consider” for additional guidelines for newer biotech products (will go over these later in semester) Manufacturing facility Most manufacturing facilities have requirements, but some specifics to biotech products, especially – Clean room – Water Clean Rooms Clean room views Environmentally controlled areas Critical steps for bio/injectable drugs are produced in clean rooms Contain high efficiency particulate air (HEPA) filters in the ceiling Figure 3.1 page 98 of chapter Classification of Clean Rooms for Pharma industry Class # microrganisms/m3 of air A <1 B 5 C 100 D 500 See table 3.5 page 100 of chapter Other considerations Exposed surfaces – smooth, sealed, nonpenetrable surface Chemically-resistant floors and walls Fixtures (lights, chairs, etc.) minimum and easily cleaned Proper entry of materials and personnel into clean room to reduce risk of contamination in clean room Gowned person in Clean room Clean Room clothing Covers most of operators body Change in a separate room and enter clean room via an air lock Clothing made from non-shredding material Number of people in a clean room at once limited to only necessary personnel (helps with automated processes) CDS Cleaning, decontamination and sanitization C- removal or organic and inorganic material that may accumulate D-inactivation and removal of undesired materials S- destroying and removing viable microorganisms CDS cont’d Done on surfaces that either are direct or indirect contact with the product Examples of surfaces in both categories? CDS of process equipment Of course trickier because comes in contact with the final product Clean equipment, then rid equipment of cleaning solution Last step involves exhaustive rinsing of equipment with pure water – – – WFI Followed by autoclaving if possible If possible use CIP (cleaning in place) Examples of CIP agents used to clean chromatography columns 0.5-2.0 M NaCl Non-ionic detergents 0.1-1.0 M NaOH Acetic Acid Ethanol EDTA Protease Water WFI- talked about this extensively before 30,000 liters of WFI needed for 1kg of a recombinant protein Use tap water just for non-critical tasks Purified water – not as pure as WFI, but used for limited purposes (in cough medicines, etc.) WFI used exclusively in downstream processing Will not cover pages 105-112- water and documentation pages Sources of Biopharmaceuticals Genetic engineering of recombinant expression systems Your talks will be about types of systems and how they are used- mammalian cells, yeast, bacteria etc. Most approved products so far produced in E. coli or mammalian cell lines E. coli Cultured in large quantities Inexpensive (relatively speaking) Generation of quantities in a short time Production facilities easy to construct anywhere in the world Standard methods (fermentation) used Current products from E. Coli tPA (Ekokinase) Insulin Interferon Interleukin-2 Human growth hormone Tumor necrosis factor Heterologous systems Expression of recombinant proteins in cells where the proteins do not naturally occur Insulin first in E. coli Remember the drawbacks of expression in E. coli? Other problems with E. coli Most proteins in E. coli expressed intracellularly Therefore, recombinant proteins expressed in E. coli accumulate in the cytoplasm Requires extra primary processing steps (e.g. cellular homogenization) and more purification (chromatography) Other problems with E. coli, cont’d Inclusion bodies – – – Insoluble aggregates of partially folded product Heterologous expressed proteins overload the normal protein-folding machinery Advantage- inclusion bodies are very dense, so centrifugation can separate them from desired material Preventing inclusion bodies Lower growth temperature (from 37C to 30C) Use a fusion protein (thioredoxin) - native in E. coli – protein expressed at high levels and remains soluble Expression in animal cells Major advantage- correct PT modifications Naturally glycosylated proteins produced in: – – – CHO - Chinese hamster ovary BHK - baby hamster kidney HEK – human embryonic kidney Current products from animal cells tPA FSH Interferon - Erythropoietin FSH Factor VIIa Disadvantages of animal cells (compared to E. coli) Complex nutritional requirements Slower growth More susceptible to damage Increased costs WILL NOT cover bottom of page 116 to page 124 (up to biopharmaceuticals)- you will cover these in your presentations Final Product Production Focus on E. coli and mammalian systems Process starts with a single aliquot of the Master Cell Bank Ends when final products is in labeled containers ready to be shipped to the customer Production: Upstream and Downstream Upstream: initial fermentation process; yields initial generation of product Downstream: purification of initial product and generation of finished product, followed by sealing of final containers biomanufacturing process overview Upstream processing Remove aliquot from MCB Inoculate sterile medium and grow (starter culture) Starter culture used to inoculate larger scale production culture Production culture inoculates bioreactor Bioreactors few to several thousand liters See figure 3.13 of chapter (page 129) Upstream cont’d Pages 129-133 go over specific details for microbial fermentation Pages 133-134 go over specific details for animal cell culture Properties of animal cells – Anchorage dependent – Grow as a monolayer – Contact inhibited – Finite lifespan – Longer doubling times – Complex media requirements Downstream processing Diagram page 135 of chapter 3 Detailed steps considered confidential Clean room conditions for downstream Downstream cont’d Steps involved (intracellular products – E. coli.) – mammalian products secreted in media, so easier to isolate) – – – – – – Centrifugation or filtration Homogenization Removal of cellular debris Concentration of crude material (by precipitation or ultra filtration) High resolution chromatography (HPLC) Formulation into the final product Downstream cont’d Final product formulation – – – – Chromatography yields 98-99% pure product Add excipients (non active ingredients), which may stabilize the final product Filtration of final product, to generate sterile product Freeze drying (lyophilization) if product if to be sold as a powder (dictated by product stability) Separation methods Page 142,tables 3.18 and 3.19 Familiar with: – – – Ion-exchange Gel-filtration Affinity chromatography Protein A chromatography Immunoaffinity chromatography Factors that influence biological activity Denature or modify proteins Results in loss of/reduced protein activity Need to minimize loss in downstream work Problems can be chemical (e.g., oxidizing, detergents); physical (e.g., pH, temperature); or biological (e.g., proteolytic degradation) Table 3.20 page 143 Proteolytic degradation Hydrolysis of one or more peptide bonds Results in loss of biological activity Trace quantities of proteolytic enzymes or chemical influences Several classes of proteases: – – – – Serine Cysteine Aspartic Metalloproteases (also in other ppt) Protease inhibitors PMSF – serine and cysteine proteases Benzamidine – serine proteases Pepstatin A – aspartic proteases EDTA – metalloproteases a.a residue known to be present at active site of protein, so disruption of it causes loss of activity Others (mentioned before) Deamidation – hydrolysis of side chain of asparagine and glutamine – Oxidation and disulphide exchange – Happens at high temp and extreme pH Oxidation by air (met and cys in particular) Alterations of glycosylation patterns in glycoproteins (more than one sugar) – Affect activity or immunological properties Excipients Substances added to final product to stabilize it Serum albumin – – – Withstands low pH or elevated temps Keeps final product from sticking to walls of container Stabilize native conformation of protein Excipients cont’d Amino acids – Alcohols (and other polyols) – Glycine – stabilizes interferon, factor VIII, stabilizes against heat Stabilize proteins in solution Surfactants – Reduces surface tension; proteins don’t aggregate, so don’t denature Final product fill See figure 3.27 page 153 Bulk product gets QC testing Passage through 0.22 m filter for final sterility Aceptically filled into final product containers Uses automated liquid handling systems Final product fill cont’d Freeze drying (lyophilization) Yields a powdered product Reduces chemical and biological degradation of final product Longer shelf life than products in solution Storage for parenteral products (those administered intravenously or injected) Freeze drying cont’d Need to add cryoprotectors – – – – Glucose or sucrose Serum albumin Amino acids Polyols Freeze drying can be done in many steps Labeling and Packing After sealed in final container, product quarantined Samples are QC’d Check potency, sterility and final volume Detection and quantitation of excipients Highly automated procedures Labeling function critical- biggest error where many products are made Label Name and strength of product Specific batch number Date of manufacture and expiry date Required storage conditions Name of manufacturer Excipients included Correct mode of usage Other final product items Biopharmaceutical products undergo more testing than traditional pharma products Products made in recombinant systems have more potential to be contaminated than synthetic chemical drugs Larger, more complex molecules