BIOPHARMACEUTICALS BIOCHEMISTRY AND BIOTECHNOLOGY - PART 3 potx

manufactured to exacting specifications laid down in publications termed ‘pharmacopoeias’. There are more than two dozen pharmacopoeias published world-wide, most notably the United States Pharmacopoeia (USP), the European Pharmacopoeia (Eur. Ph.) and the Japanese Pharmacopoeia. The products listed in these international pharmacopoeias are invariably generic drugs (i.e. drugs no longer patent-protected, which can be manufactured in any pharmaceutical facility holding the appropriate manufacturing licence). The vast bulk of such substances are traditional chemical-based drugs, and biological substances such as insulin and various blood products. Two sample monographs from the European Pharmacopoeia are reproduced in Appendix 3. Future editions of such pharmacopoeias are likely to include a growing number of biopharmaceuticals, particularly as many of these begin to lose their patent protection. Martindale, The Extra Pharmacopoeia Martindale, The Extra Pharmacopoeia (often simply referred to as ‘Martindale’) represents an additional publication of relevance to the pharmaceutical industry. Unlike the pharmacopoeias discussed above, Martindale is not a book of standards. The aim of this encyclopaedic publication is to provide concise, unbiased information (largely summarized from the peer- reviewed literature) regarding drugs of clinical interest. The first edition of Martindale was published in 1883 by William Martindale and the 30th edition was published in 1993. It contains information in monograph format on over 5000 drugs in clinical use. The vast bulk of substances described are chemical-based pharmaceuticals, as well as traditional biological substances such as antibiotics, certain hormones and bloo d products. Recent editions, however, carry increasing numbers of monographs detailing biopharmaceuticals — a reflection of their growing importance in the pharmaceutical industry. Martindale is largely organized into chapters that detail groups of drugs having sim ilar clinical uses or actions (Table 3.1). The information presented in a monograph detailing any particular drug will usually include: . its physiochemical characteristics; . absorption and fate; . uses and appropriate mode of administration; . adverse/side effects; . suitable dosage levels. In addition, summaries of published papers/reviews of the substance in question are included. Because of its clinical emphasis, Martindale represents a valuable drug information source to pharmacists and clinicians, but also provides much relevant drug information to personnel engaged in pharmaceutical manufacturing. GUIDES TO GOOD MANUFACTURING PRACTICE All aspects of pharmaceutical manufacture must comply with the most rigorous standards to ensure consistent production of a safe, effective product. The principles underlining such standards are summarized in publications which detail good manufacturing practice (GMP). Pharmaceutical manufacturers must be familiar with the principles laid down in these publications and they are legally obliged to ensure adoption of these principles to their specific manufacturing process. Regulatory authority personnel will assess compliance of the manufacturer with these principles by unde rtaking regular inspections of the facility. The 94 BIOPHARMACEUTICALS subsequent granting/renewing (or refusing/revoking) of a manufacturing licence depends largely upon the level of compliance found during the inspection. Although separate guides to pharmaceutical GMP are published in different world regions the principles outlined in them all are largely similar. In Europe, for example, the European Union (EU) publishes the EU Guide to Good Manufacturing Practice for Medicinal Products. This guide consists of a number of chapters, each of which is concerned with a specific aspect of pharmaceutical manufacture (Table 3.2). The principles therein often appear little more than common-sense guidelines, e.g. the principles outlined in the chapter detailing GMP in relation to personnel could be summarized as: . an adequate number of sufficiently qualified, experienced personnel must be employed by the manufacturer; . key personnel, such as the heads of production and quality control, must be independent of each other; THE DRUG MANUFACTURING PROCESS 95 Table 3.1. List of the major headings under which various drugs are described in Martindale, The Extra Pharmacopoeia Analgesics and anti-inflammatory agents Cardiac inotropic agents Non-ionic surfactants Anthelmintics Chelating agents, antidotes and antagonists Nutritional agents and vitamins Anti-arrhythmic agents Colouring agents Opioid analgesics Anti-bacterial agents Contrast media Organic solvents Anti-coagulants Corticosteroids Paraffins and similar bases Anti-depressants Cough suppressants, expectorants and mucolytics Parasympathomimetics Anti-diabetic agents Dermatological agents Pesticides and repellants Anti-epileptics Diagnostic agents Preservatives Anti-fungal agents Disinfectants Prophylactic anti-asthma agents Anti-gout agents Diuretics Prostaglandins Anti-hypertensive agents Dopaminergic anti- parkinsonian agents Radiopharmaceuticals Anti-malarials Electrolytes Sex hormones Anti-migraine agents Gases Skeletal muscle relaxants Anti-muscarinic agents Gastrointestinal agents Soaps and other anionic surfactants Anti-neoplastic agents and immunosuppressants General anaesthetics Stabilizing and suspending agents Anti-protozoal agents Haemostatics Stimulants and anorectics Anti-thyroid agents Histamine H 1 -receptor antagonists Sunscreen agents Anti-viral agents Hypothalamic and pituitary hormones Sympathomimetics Anxiolytic sedatives, hypnotics and neuroleptics Iodine and iodides Thrombolytic agents b-Adrenoceptor blocking agents Iron and iron components Thyroid agents Blood and blood products Lipid-regulating agents Vaccines, immunoglobulins and antisera Blood substitutes and plasma expanders Local anaesthetics Vasodilators Calcium-regulating agents Nitrates and other anti-angina agents Xanthines . personnel should hav e well-defined job descriptions, and should receive training such that they can adequately perform all their duties; . issues of personal hygiene should be emphasized, so as to prevent product contamination as a result of poor hygiene practices. The chapter detailing premises and equipment describes similar obvious principles, such as: . all premises and equipment should be designed, operated and serviced such that it is capable of carrying out its intended function effectively; . facility design and equipment use should be such as to avoid cross-contamination or mix-up between different products; . sufficient storage area must be provided, and a clear demarcation must exist between storage zones for materials at different levels of processing (i.e. raw materials, partially processed product, finished product, rejected product, etc.); . quality control labs must be separated from production and must be designed and equipped to a standard allowing them to fulfil their intended function. Some of the principles outlined in the guide are sufficiently general to render them ap plicable to most manufacturing industries. However, many of the guidelines are far more specific in nature (e.g. guidelines relating to the requirement for dedicated facilities when manufacturing specific products, including some antibiotics and hormones). In addition to the main chapters, the EU guide also contains a series of 14 annexes (Table 3.3). These lay down guidelines relating mainly to the manufacture of specific pharmaceutical substances, such as radioactive pharmaceuticals or products derived from human blood or human plasma. One such annex (manufacture of biological medicinal products for human use) is included as appendix 4 of this textbook. Most of the principles outlined in such guides to GMP are equally as applicable to the manufacture of traditional pharmaceuticals as to the newer biopharmaceutical preparations. However, the regulatory authorities have found it necessary to publish additional guidelines relating to many of the newer biotechnology-based biopharmaceuticals. Examples include the ‘Points to Consider’ series, which contain guidel ines relating to safe producti on, e.g. of therapeutic monoclonal antibodies by hybridoma technology, and recombinant biopharma- ceuticals produced by genetic engineering (Table 3.4). Guides to GMP and ancillary publ ications are among the most significant publications governing the practical aspects of drug manufacture in the pha rmaceutical industry. The 96 BIOPHARMACEUTICALS Table 3.2. List of chapter titles present in the Guide to Good Manufacturing Practice in the European Community (i.e. Vol. IV of the Rules Governing Medicinal Products in the European Union) 1 Quality management 2 Personnel 3 Premises and equipment 4 Documentation 5 Production 6 Quality control 7 Contract manufacture and analysis 8 Complaints and product recall 9 Self-inspection implementation of the exacting standards laid down in these publications ensures total quality assurance in the drug manufacturing process. THE MANUFACTURI NG FACILITY Appropriate design and layout of the pharmaceutical facility is an issue central to the production of safe, effective medicines. In common with many other manufacturing facilities, pharmaceutical facilities contain specific production, quality control (QC) and storage areas, etc. However, certain aspects of facility design and operation are unique to this industry, in particular with regard to manufacturers of parenteral (injectable) products. Incorporation of these features is rendered mandatory by guides to pha rmaceutical GMP. Particularly noteworthy features, including clean room technology and generation of ultra pure water, are reviewed below. While the majority of critical manufacturing operations of injectable pharmaceuticals (e.g. most biopharmaceuticals) occurs in specialized clean areas, proper design and maintenance of non-critical areas (e.g. storage, labelling and packing areas) is also vital to ensure overall product safety. Strict codes of hygiene also apply to these non-critical areas. THE DRUG MANUFACTURING PROCESS 97 Table 3.3. List of the specific annexes now associated with good manufacturing practice (GMP) for medicinal products (i.e. Vol. IV of ‘the Rules Governing Medicinal Products in the European Union’) 1 Manufacture of sterile medicinal products 2 Manufacture of biological medicinal products for human use 3 Manufacture of radiopharmaceuticals 4 Manufacture of veterinary medicinal products other than immunologicals 5 Manufacture of immunological veterinary medicinal products 6 Manufacture of medicinal gases 7 Manufacture of herbal medicinal products 8 Sampling of starting and packaging materials 9 Manufacture of liquids, creams and ointments 10 Manufacture of pressurized metered dose aerosol preparations for inhalation 11 Computerized systems 12 Use of ionizing radiation in the manufacture of medicinal products 13 Good manufacturing practice for investigational medicinal products 14 Manufacture of products derived from human blood or human plasma Table 3.4. Some of the ‘Points to Consider’ publications available from the FDA. Many of these can now be downloaded directly from the FDA Center for Biologics Evaluation and Research (CBER) home page, the address of which is: http://WWW.fda.gov/cber/ Points to Consider in the Manufacture and Testing of Monoclonal Antibody Products for Human Use Points to Consider on Plasmid DNA Vaccines for Preventive Infectious Disease Indications Points to Consider in the Manufacture and Testing of Therapeutic Products for Human Use Derived from Transgenic Animals Points to Consider in the Characterization of Cell Lines used to Produce Biologicals Points to Consider in the Production and Testing of New Drugs and Biologicals Produced by Recombinant DNA Technology Points to Consider in Human Somatic Cell Therapy and Gene Therapy Clean rooms Clean rooms are environmentally controlled areas within the pharmaceutical facility in which critical manufa cturing steps for injectable/sterile (bio)pharmaceutic als must be undertaken. The rooms are specifically designed to protect the product from contamination. Common potential contaminants include microorganisms and particulate matter. These contaminants can be airborne, or derived from process equipment, personnel, etc. Clean rooms are designed in a manner that allows tight control of entry of all substances (e.g. equipment, personnel, in-process product, and even air; Figures 3.1 and 3.2). In this way, once a clean environment is generated in the room, it can easily be maintained. A basic feature of clean room design is the presence in their ceilings of high-efficiency particulate air (HEPA) filters. These depth filters, often several inches thick, are generally manufactured from layers of high-density glass fibre. Air is pumped into the room via the filters, generating a constant downward sweeping motion. The air normally exits via exhaust units, generally located near ground level. This motion promotes continued flushing from the room of any particulates generated during processing (Figure 3.1). 98 BIOPHARMACEUTICALS Figure 3.1. Diagrammatic illustration of the flow pattern of HEPA-filtered air through a typical clean room. Air is pumped into the room through HEPA filters (see text) located in the ceiling, and exits via extract units, normally located at floor level. Although the air flow is non-unidirectional (i.e. not true laminar flow), it generates a constant downward sweeping motion, which helps remove air-borne particulate matter from the room HEPA filters of different particulate-removing efficiency are available, allowing the construction of clean rooms of various levels of cleanliness (Table 3.5). Such rooms are classified on the basis of the number of (a) airborne particles and (b) viable micro organisms present in the room. In Europe clean rooms are classified as grade A, B, C or D (in order of decreasing cleanliness). In the USA, where approximately similar specifications are used, cleanrooms are classified as class 100 (equivalent to grade A/B), class 10 000 (grade C) or class 100 000 (grade D). HEPA filters in grade B, C and D clean rooms are normally spaced evenly in the ceiling, occupying somewhere in the region of 20–25% of total ceiling area. Generation of class A clean room conditions generally requires a modified design. The use of high-specification HEPA filters, along with the generation of a unidirectional downward air distribution pattern (i.e. laminar flow), is essential. This is only achieved if filter occupancy of ceiling space is 100%. Most commonly, portable (horizontal or vertical) laminar flow cabinets placed in class B cleanrooms are used to generate localized class A conditions. In more extensive facilities, however, an entire class A room may be constructed. THE DRUG MANUFACTURING PROCESS 99 Figure 3.2. Generalized clean room design. Entry of personnel occurs via changing rooms, where the operators first remove their outer garments and subsequently put on suitable clean room clothing (see e.g. Figure 3.3). All raw materials, portable equipment, etc. enters the clean room via a transfer lock. After being placed in the transfer lock, such items are sanitized (where possible) by, for example, being rubbed down with a disinfectant solution. They are then transferred into the clean room proper, by clean room personnel. Processed product usually exits the clean room via an exit transfer lock and personnel often exit the room via a changing room separate from the one they entered (in some cases, the same changing room is used as an entry and exit route). Note that, in practice, product may be processed in a number of different (adjacent) clean rooms While an effective HEPA air-handling system is essential to the generation of clean room conditions, many additional elements are equally important in maintaining such conditions. Clean room design is critical in this regard. All exposed surfaces should have a smooth, sealed impervious finish in order to minimiz e accumulation of dirt/microbial particles and to facilitate effective cleaning procedures. Floors, walls and ceilings can be coated with durable, chemical- resistant materials, such as epoxy resins, polyester or PVC coatings. Alternatively, such surfaces may be completely overlaid with smooth vinyl-based sheets, thermally welded to ensure a smooth, unbroken surface. Fixtures within the room (e.g. work ben ches, chairs, equipment, etc.) should be kept to a minimum, and ideally be designed and fabricated from material that facilitates effective cleaning (e.g. polished stainless steel). The positioning of such fixtures should not hinder effective cleaning processes. Pipework should be installed in such a way as to allow effective cleaning around them and the presence of uncleanable recesses must be avoided. All corners and joints between wal ls and ceilings or floors are rounded, and equipment with movable parts (e.g. motors, pumps) should be encased. The transfer of processing materials, or entry of personnel into clean areas, carries with it the risk of reintroduction of microorganisms and particulate matter. The principles of GMP minimizes such risks by stipulating that entry of all substances/personnel into a clean room must occur via air-lock systems (Figure 3.2). Such air-locks, with separate doors opening into the clean room and the outside environment, act as a buffer zone. All materials/process equipment entering the clean area are cleaned, sanitized, (or autoclaved if practicable) outside this area, and then passed directly into the transfer lock, from where it is transferred into the clean room by clean room personnel. An interlocking system ensures that both doors of the transfer lock are never simultaneously open, thus precluding formation of a direct corridor between the uncontrolled area and the clean area. Transfer locks are also positioned between adjacent clean rooms of different grades of cleanliness. Personnel represent a major potential source of process contaminants (e.g. microorganisms, particulates, etc.), hence they are required to wear specialized protective clothing when working in clean areas. Operators enter the clean area via a separate air lock, which serves as a changing area. They remove their outer clothing at one end of the area, and put on (usually pre-sterilized) gowns, face masks and gloves at the other end of the changing area. Clean room clothing is made from non-shedding material, and c overs most of the operator’s body (Figure 3.3). 100 BIOPHARMACEUTICALS Table 3.5. Specifications laid down (in the EC Guide to Good Manufacturing Practice for Medicinal Products) for class A, B, C and D clean rooms, as used in the pharmaceutical industry Grade Maximum permitted number of particles per m 3 of clean room air Maximum permitted number of viable microorganisms per m 3 of clean room air 0.5 mm particle diameter 5.0 mm particle diameter A 3500 0 Statistically <1 B 3500 0 5 C 350 000 2000 100 D 3 500 000 20 000 500 A high standard of operator personal hygiene is also of critical importance, and all personnel should receive appropriate training in this regard. Only the minimum number of personnel required should be present in the clean area at any given time. This is facilitated by a high degree of process automation. The installation in clean room walls of windows that serve as observational decks, coupled with intercom systems, also helps by facilitating a certain degree of supervision from outside the clean area. Cleaning, decontamination and sanitation (CDS) Essential to the production of a safe, effective product is the application of an effective cleaning, decontamination and sanitation (CDS) regime in the manufacturing facility. Cleaning involves the removal of ‘dirt’, i.e. miscellaneous organic and inorganic material which may accumulate in process areas or equipment during production. Decontamination refers to the inactivation and removal of undesirable substances, which generally exhibit some specific biological activity likely to be detrimental to the health of patients receiving the drug. Examples include endotoxins, viruses, or prions. Sanitation refers specifically to the destruction and removal of viable microorganisms (i.e. bioburden). Effective CDS procedures are routinely applied to: . surfaces in the immediate manufacturing area which do not come into direct contact with the product (e.g. clean room walls and floors, work tops, ancillary equipment); . surfaces coming into direct contact with the product (e.g. manufacturing vessels, chromatographic columns, product filters, etc.). THE DRUG MANUFACTURING PROCESS 101 Figure 3.3. Operator wearing clean room clothing suitable for working under aseptic conditions. Note that his entire body is covered. This precludes the possibility of the operator shedding skin, microorganisms or other particulate matter into the product. Photo courtesy of SmithKline Beecham Biological Services s.a., Belgium CDS of the general manufacturing area Primary cleaning generally entails scrubbing/rinsing the target surface with water or a detergent solution. Subsequent decontamination/sanitation procedures vary, often involving application of disinfectants or other bacteriocidal agents. Thorough cleaning prior to disinfectant application is essential, as dirt can inactivate many disinfectants or shield microorganisms from disinfectant action. A range of suitable disinfectants are commercially available, containing acti ve ingredients including alcohols, phenol, chlorine and iodine. Different disinfectants are often employed on a rotating basis, to minimize the likelihood of the development of disinfectant-resistant microbial strains. CDS of clean room walls, floors and accessible surfaces of clean room equipment is routinely undertaken between production runs. The final CDS step often entails ‘fogging’ the room. This is achieved by placing some of the disinfectant in an a erosol-generating device (a ‘fogging machine’). This generates a fine disinfectant mist, or fog, within the clean room, capable of penetrating areas difficult to reach in any other manner. CDS of process equipment CDS of surfaces/equipment coming into direct contact with the product requires special consideration. While CDS procedures of guaranteed efficiency must be applied, it is imperative that no trace of the CDS agents subsequently remain on such surfaces, as this would result in automatic product contamination. The final stage of most CDS procedures, as applied to such process equipment, involves exhaustive rinsing with highly pure water (water for injections; WFI). This is followed if at all possible by autoclaving. CDS of processing and holding vessels, as well as equipment that is easily detachable/ dismantled (e.g. homogenizers, centrifuge rotors, flexible tubing filter housing, etc.), is usually relatively straightforward. However, CDS of large equipment/process fixtures can be more challenging, due to the impracticality/undesirability of their dismantling. Examples include the internal surfaces of fermentation equipment, large processing/storage tanks, process-scale chromatographic columns, fixed piping through which product is pumped, etc. Specific ‘cleaning in place’ (CIP) procedures can generally be used to accommodate such equipment. A detergent solution can be pumped through fixed pipework, followed by WFI and then the passage of sterilizing ‘live’ steam generated from WFI. Internal surfaces of fermentation/processing vessels can be scrubbed down. Such vessels are generally jacketed (Figure 3.4), thus allowing temperature control of their contents by passage of co oling water/steam through the jacket, as appropriate. Passage of steam through the jacket of the empty vessel facilitates sterilization of its internal surfaces by dry heat. The cleaning of process-scale chromatography systems used in the purification of biopharmaceuticals can also present challenges. Although such systems are disassembled periodically, this is not routinely undertaken after each production run. CIP protocols must thus be applied periodically to such systems. The level and frequency of CIP undertaken will depend largely on the level and type of contaminants present in the product-stream applied. Columns used during the earlier stages of purification may require more frequent attention than systems used as a final ‘clean-up’ step of a nearly pure protein product. While each column is flushed with buffer after each production run, a full-scale CIP procedure may be required only after every 3–10 column runs. Most of the contaminants present in such columns are acquired from these previous production runs. 102 BIOPHARMACEUTICALS Processing of product derived from microbial sources can result in contamination of chromatographic media with lipid, endotoxins, nucleic acids and other biomolecules. Application of plant-derived extracts can result in column fouling with pigments and negatively charged polyphenolics, as well as various substances released from plant cell vacuoles (many of which are powerful protein precipitants/denaturants). In addition, some plant-derived enzymes are capable of degrading certain carbohydrate-based (e.g. dextran) chromatographic media. Chromatography of extracts from animal/human tissue can result in column contamination with infectious agents or biomolecules, such as lipids. Furthermore, buffer components may sometimes precipitate out of solution within the column. Fortunately, most types of modern chromatograph ic media a re resistant to a range of harsh physicochemical influences that may be emp loyed in CIP protocols (Table 3.6). CIP protocols for chromatography columns are normally multistep, consisting of sequential flushing of the gel with a series of CDS agents. THE DRUG MANUFACTURING PROCESS 103 Figure 3.4. Diagram of a typical jacketed processing vessel. Such vessels are usually made from high grade stainless steel. By opening/closing the appropriate valves, steam or cold water can be circulated through the jacket. In this way, the vessel’s contents can be heated or cooled, as appropriate. In addition, passage of steam through the jacket of the empty vessel will effectively sanitize its internal surfaces Table 3.6. The range of CIP agents often used to clean/sanitize chromato- graphic columns. Most CIP protocols would make use of two or more of these agents, allowing them to sequentially percolate through the column at a slow flow rate. Contact time can range from several minutes to overnight. NaOH is particularly effective at removing most contaminant types 0.5–2.0 M NaCl Non-ionic detergents (0.1–1.0%) NaOH (0.1–1.0 M) Acetic acid (20–50%) Ethanol ($20%) EDTA ($1.0 mM) Protease solution Dilute buffer [...]... E coli, CHO E coli Interferon-a Interferon-g Interleukin-2 (IL-2) Granulocyte colony-stimulating factor (G-CSF) Human growth hormone (hGH) E E E E Follicle-stimulating hormone (FSH) CHO Interferon-b CHO Erythropoietin CHO Glucocerebrosidase CHO Factor VIIa BHK coli coli coli coli E coli Source THE DRUG MANUFACTURING PROCESS 1 13 Table 3. 10 Levels of expression of various biopharmaceuticals produced in... BHK ¼ baby hamster kidney) E coli (and additional prokaryotic systems, e.g Bacilli) Yeast (particularly Saccharomyces cerevisiae) Fungi (particularly Aspergillus) Animal cell culture (particularly CHO and BHK cell lines) Transgenic animals (focus thus far is upon sheep and goats) Plant-based expression systems (various) Insect cell culture systems Table 3. 9 Some biopharmaceuticals currently on the... target protein production to the mammary gland Harvesting of the protein thus simply requires the animal to be milked Mammary-specific expression can be achieved by fusing the gene of interest with the promoter-containing regulatory sequence of a gene coding for a milk-specific protein Regulatory sequences of the whey acid protein (WAP), b-casein and a- and b-lactoglobulin genes have all been used to... interleukins (interleukin-1 being an important exception) Interferon-b and -g (most interferon-as are unglycosylated) Colony stimulating factors Tumour necrosis factors Gonadotrophins (follicle stimulating hormone, luteinizing hormone and human chorionic gonadotrophin) Blood factors (e.g factors VII, VIII and IX) Erythropoietin Thrombopoietin Tissue plasminogen activator a1 -Antitrypsin Intact monoclonal... contaminants (Table 3. 7) A multi-step purification procedure is then undertaken, which usually contains some or all of the following steps (see also Figure 3. 5): the incoming water is collected in a storage or ‘break’ tank, from where it is pumped through a depth filter, organic trap and carbon filter The depth filter often contains a mixture of granular anthracite, washed sand, and gravel Solids and colloidal... the murine WAP gene regulatory sequence to drive expression (Figure 3. 8) Goats and sheep have proved to be the most attractive host systems, as they exhibit a combination of attractive characteristics These include: high milk production capacities (Table 3. 14); ease of handling and breeding, coupled to well-established animal husbandry techniques A number of additional general characteristics may... DRUG MANUFACTURING PROCESS 121 Table 3. 14 Typical annual milk yields (litres) as well as time lapse between generation of the transgene embryo and first product harvest (first lactation) of indicated species Species Annual milk yield (l) Time to first production batch (months) Cow Goat Sheep Pig Rabbit 6000–9000 700–800 400–500 250 30 0 4–5 33 36 18–20 18–20 16–17 7 Table 3. 15 Some physicochemical properties... established and hence recombinant protein synthesis occurs within the silkworms After acid extraction, neutralization and clarification, the recombinant product is purified chromatographically A two-step affinity procedure using blue sepharose dye affinity and copper chelate sepharose chromatography is employed (see later in this chapter) After a gel-filtration step, excipients (sorbitol and gelatin) are added and. .. production-scale starter culture, which is used to inoculate the production-scale bioreactor (Figure 3. 13) The medium composition and fermentation conditions required to promote optimal cell growth/product production will have been established during initial product development, and routine batch production is a highly repetitive, highly automated process Bioreactors are generally manufactured from high-grade... products sold in liquid form are dissolved, and in which freeze-dried biopharmaceuticals will be reconstituted immediately prior to use It is also used for ancillary processes, such as the cleaning of equipment, piping and product-holding tanks It is additionally used to clean/rinse the vials into which the final product is filled It has been estimated that up to 30 000 litres of water is required to support . substitutes and plasma expanders Local anaesthetics Vasodilators Calcium-regulating agents Nitrates and other anti-angina agents Xanthines . personnel should hav e well-defined job descriptions, and should. mucolytics Parasympathomimetics Anti-diabetic agents Dermatological agents Pesticides and repellants Anti-epileptics Diagnostic agents Preservatives Anti-fungal agents Disinfectants Prophylactic anti-asthma agents Anti-gout. Prostaglandins Anti-hypertensive agents Dopaminergic anti- parkinsonian agents Radiopharmaceuticals Anti-malarials Electrolytes Sex hormones Anti-migraine agents Gases Skeletal muscle relaxants Anti-muscarinic