LARGE SCALE PRODUCTION OF STERILE DOSAGE FORMS

Manufacture of parenteral formulations In general, sterile products used for parenterals, must be: 1- Free from chemical and physical contaminants 2- Accurately and correctly compounded 3- Pharmaceutically elegant 4- Pyrogen-free 5- Stable for their intended shelf-life. 6- They must be packaged in a manner that will assure maintenance of their quality until used.

*Two essential requirements of parenteral formulations are sterility and the absence of pyrogens. These two requirements directly influence the methods by which parenteral formulations are manufactured. Two categories of sterile products are presents: Those that can be sterilized in final container (terminally sterilize Those that cannot be terminally sterilized and must be aseptically prepared. *There are basic differences between the production of sterile drug products using aseptic processing and production using terminal sterilization.

*Terminal sterilization usually involves filling and sealing product containers under high-quality environmental conditions. Products are filled and sealed in this type of environment to minimize the microbial and particulate content of the in-process product and to help ensure that the subsequent sterilization process is successful. In most cases, the product, container, and closure have low bioburden, but they are not sterile. The product in its final container is then subjected to a sterilization process such as heat or irradiation. NB: Bioburden is normally defined as the number of bacteria living on a surface that has not been sterilized.

*In an aseptic process, the drug product, container, and closure are first subjected to sterilization methods separately, as appropriate, and then brought together. Before aseptic assembly into a final product, the individual parts of the final product are generally subjected to various sterilization processes. For example, glass containers are subjected to dry heat; rubber closures are subjected to moist heat; and liquid dosage forms are subjected to filtration. Each of these manufacturing processes requires validation and control. Each process could introduce an error that ultimately could lead to the distribution of a contaminated product. Any manual or mechanical manipulation of the sterilized drug, components, containers, or closures prior to or during aseptic assembly poses the risk of contamination and thus necessitates careful control. A terminally sterilized drug product, on the other hand, undergoes final sterilization in a sealed container, thus limiting the possibility of error.

Source of contamination 1- The air supply: Heating ventilation and Air conditioning (HVAC) (Treated with Laminar air flow – HEPA filter). 2- People (most common): Touch contamination. Generation of particulates from shedding cells or hair.

-The skin: (nail should be scrubbed- hands and for-arms should be washed thoroughly with detergent solution) -The breath: (use masks) -Clothing: always wear sterile gown over normal clothing -The hair : long hair should be tied back and wear a cotton cap

3- The working surfaces: clean the working surfaces with bactericidal solution or ethyl alcohol. 4- Equipment: Inappropriate materials of construction 5- Packaging: Improper closure preparation processes , compromised container closure integrity, degradation of closures and leaching of compounds from the closures 6- Infiltration Particles from adjacent spaces (e.g. anteroom) 7- Internal design Walls, floors, ceilings.

GMP REQUIREMENTS FOR MANUFACTURING OF PARENTERALS 1- The flow of components, drug product containers, closures, labeling, in-process materials, and drug products through the building or buildings shall be designed to prevent contamination. 2- Operations shall be performed within specifically defined areas of adequate size. There shall be separate or defined areas or such other control systems for the firm’s operations as are necessary to prevent contamination or mix-ups during the course Aseptic processing, which includes as appropriate: (i) Floors, walls, and ceilings of smooth, hard surfaces that are easily cleanable (ii) Temperature and humidity controls

(iii) An air supply filtered through high-efficiency particulate air filters under positive pressure, regardless of whether flow is laminar or non-laminar (iv) A system for monitoring environmental conditions (v) A system for cleaning and disinfecting the room and equipment to produce aseptic conditions (vi) A system for maintaining any equipment used to control the aseptic conditions. 3- Equipment for adequate control over air pressure, micro-organisms, dust, humidity, and temperature shall be provided when appropriate for the manufacture, processing, packing, or holding of a drug product.”

4- Air filtration systems, including prefilters and particulate matter air filters, shall be used when appropriate on air supplies to production areas.   5- Equipment used in the manufacture, processing, packing, or holding of a drug product shall be of appropriate design, adequate size, and suitably located to facilitate operations for its intended use and for its cleaning and maintenance.” 6- Equipment shall be constructed so that surfaces that contact components, in-process materials, or drug products shall not be reactive, additive, or absorptive so as to alter the safety, identity, strength, quality, or purity of the drug product beyond the official or other established requirements.”

8-Equipment and utensils shall be cleaned, maintained, and sanitized at appropriate intervals to prevent malfunctions or contamination that would alter the safety, identity, strength, quality, or purity of the drug product beyond the official or other established requirements. 9-Appropriate written procedures, designed to prevent microbiological contamination of drug products purporting to be sterile, shall be established and followed. Such procedures shall include validation of any sterilization 10-Operators within the manufacturing area must wear special (sterile) work clothing, ensuring that there is no operator contamination of the product and environment process.

Objectives of Aseptic Processing Aseptic processes are designed: 1- To minimize exposure of sterile articles to the potential contamination hazards of the manufacturing operation. 2- To Limit the duration of exposure of sterile product elements 3- To provide the highest possible environmental control 4- To optimize process flow 5- To design equipment appropriately. 6- To prevent entrainment of lower quality air into the Class 100 (ISO 5) clean area are essential to achieving high assurance of sterility.

Key factors contributing to the preparation of sterile products For convenience, the key factors contributing to the preparation of sterile products of high quality can be divided into four categories: 1- Components (raw materials) 2- Facilities 3- Environmental control 4- Operators

Requirements for the manufacture of aseptically prepared products – Manufacturing environment • Clean areas • Personnel – Preparation and filtration of solutions – Pre-filtration bioburden – Filter integrity/validation – Equipment/container preparation and sterilization – Filling Process – Validation of aseptic processes – Specific issues relating to Isolators, BFS and Bulk

Manufacturing Environment Clean room or area: Definition of clean room: A clean room or area is a room or area with environmental control of particulate contamination, temperature and humidity, constructed and used in such away as to minimize the introduction, generation and retention of the particles inside the room.   Clean rooms or areas are needed to reduce contamination levels in the product or services performed. The production of sterile preparations should be carried out in clean areas, entry to which should be through airlocks for personnel and/or for goods.

The various operations of component preparation (such as containers and closures), product preparation, filling and sterilization should be carried out in separate areas within a clean area.   Clean areas should be maintained to an appropriate standard of cleanliness and supplied with air that has passed through filters of an appropriate efficiency.

Classification of Manufacturing Areas by Air Cleanliness Facilities for processing sterile pharmaceutical products comprise clean areas controlled based on predefined airborne particle and microbiological standards. The areas are classified as critical, direct support, and indirect support areas depending on the nature of the operation to be conducted. Generally, the cleanliness of air in processing areas is defined by the number of airborne particles ≥ 0.5 μm in diameter per unit volume of air. The number of particles ≥ 5 μm in diameter may serve as a reliable parameter for early detection of environmental deterioration, if regularly monitored and evaluated by linear trend analysis

Air Table 1: Categories of clean areas Air cleanliness* *The ISO class designation in parenthesis refers to the count during operation. **There are cases where maximum allowable number may not be specified Table 1: Categories of clean areas Air Air cleanliness* Maximum allowable number of airborne particles (/m3) Count under non- operating conditions Count under operating conditions ≥ 0.5 μm ≥ 5.0 μm Aseptic processing area Critical area Grade A (ISO 5) 3,520 20 Direct support area Grade B (ISO 7) 29 3,52000 2,900 Indirect support area Grade C (ISO 8) 3,520000 29,000 Grade D 3,520.000 Dependent on process attributes **

By federal standards: Clean room have been classified into four groups. This classification is based on the particle count. The maximum allowance of particles permissible is 0.5 μm and larger or 5.0 μm and larger. (1) Class 100,000: -Particle count not to exceed a total of 100,000 particles per cubic foot of a size 0.5µ and larger or 700 particles per cubic foot of size 5.0µ and larger. (2) Class 10,000:- Particle count not to exceed a total or 10,000 particles per cubic foot of a size 0.5µ and larger or 65-70 particles per cubic foot of a size 5.0µ and larger.

(3) Class 1,000: - Particles count not to exceed a total of 1000 particles per cubic foot of a size 0.5µ and larger or 10 particles per cubic foot of a size 5.0µ and larger. (4) Class 100: - Particles count not to exceed a total of 100 particles per cubic foot of a size 0.5µ and larger

Critical Area (Grade A) 1-The critical area is a processing area where sterilized products and materials as well as their surfaces are directly exposed to the environment. The environmental conditions should be specified to be suitable for the virtual elimination of contamination risks and preservation of the sterility of products. The following processes are conducted in this area: sterilization activities (e.g. sterile connections, addition of sterile materials) prior to filling, sterile filling, and sterile closure. 2-The per-cubic-meter content of particles ≥ 0.5 μm in diameter in the critical area should be controlled to be below 3,520 under both operating (in operation) and non-operating conditions (At rest). This level of air cleanliness is designated as Grade A, Class 100, or ISO-5 according to domestic and international standards on air quality.

3-The intervention of personnel into the critical area should always be kept to a minimum. 4- The count of airborne particles and microorganisms should be regularly monitored by appropriate procedures at sites which are critical for ensuring sterility of pharmaceutical products. -It is recommended that airborne particles be continuously counted throughout aseptic processing, including during critical preparatory steps such as assembly of sterile parts that may contact pharmaceutical products. The location of monitoring should preferably be as close (≤ 30 cm) as the working place. -The frequency and method of microbiological monitoring should be carefully selected in order not to break sterility of products by the monitoring

5- Powder filling operations may generate higher counts of airborne particles than the specifications. If such a deviation occurs, the count of airborne particles should be obtained by, for example, sampling air at different locations or monitoring the count in the same room while no powder filling operation is going, and causes of the deviation should be identified to maintain air quality in the room at a required level.

Direct Support Area (Grade B) 1. The direct support area is defined as a background area of the critical area when aseptic processing is conducted using an open clean booth or restricted access barrier system (RABS). The direct support area is a working area for personnel who operate machines installed in the critical area and for those who supervise the operation of machines. The direct support area also serves as a route for the transfer of sterilized products, materials, and equipment to the critical area or for moving sterilized products from the critical area. In the latter case, appropriate measures need to be implemented to protect sterilized products or materials from direct exposure to the environment

Cont. 2. The per-cubic-meter count of particles (diameter: ≥ 0.5 μm) in the direct support area should be controlled below 352,000 and 3,520 under operating and non-operating conditions, respectively. These levels of air cleanliness are designated as Grade B, Class 10,000, or ISO-7 (under standard operating conditions) according to domestic and international standards on air quality.

Cont. 3. The count of airborne particles and microorganisms should be regularly monitored by appropriate procedures in the direct support area. The frequency and method of monitoring should be carefully selected based on evaluation results of product contamination risks in the critical area.

Indirect Support Areas (Grade C or D): 1. The indirect support area is an area used for processing materials and products prior to sterilization processes and hence materials and products are directly exposed to the environment. Example indirect support areas include an area for preparing drug solution prior to sterilization and an area for washing and cleaning sterilization equipment and apparatuses. 2. The cleanliness of the indirect support area needs to be controlled by establishing specifications for acceptable airborne particle count by taking into account the required level of contamination control and type of works performed in the area.

3. Air cleanliness of the indirect support area may be either of the following two grades. - One of the grades specifies that the per-cubic-meter particle content (diameter: ≥ 0.5 μm) should not exceed 3,520,000 and 352,000 under operating and non-operating conditions, respectively. These levels of cleanliness are designated as Grade C, Class 100,000, or ISO-8 (standard under operating conditions) according to domestic and international standards on air quality. The other grade specifies that the per-cubic-meter particle content (diameter: ≥ 0.5 μm) should not exceed 3,520,000 under non-operating conditions. This level of cleanliness is designated as Grade D.

4. Weighing and preparation processes should preferably be conducted in Grade C or cleaner areas. If powder handling might elevate the airborne particle count above the specification, air quality should be maintained below the specification by accurately determining the particle count that may cause contamination in the area, and for the determination, air should be sampled, for example, at multiple locations and/or under powder-free conditions.

Heating, Ventilating and Air Conditioning System -Air in clean areas needs to be maintained at appropriate levels by designing, instituting, and managing a suitable heating, ventilation, and air conditioning (HVAC) system. The integrity of the system should be ensured with respect to not only temporal variations due to operational activities, such as door opening and closing and facility equipment operation, but also sustained variations due to non-operational activities, such as seasonal changes in outdoor conditions or deterioration of equipment and apparatuses over time

The HVAC system and its management program are comprised of the following basic elements: temperature, relative humidity, air flow volume, air exchange rate, unidirection of air flow, pressure difference relative to adjacent rooms, integrity of HEPA filter, airborne particles count, and microbacterial count.

Temperature and Relative Humidity Temperature and relative humidity have a direct impact on the comfort of personnel and potential for microbial contamination in processing areas; therefore, these environmental parameters should be appropriately defined, controlled, monitored, and maintained at appropriate levels throughout processing.

Air -Flow It is critical to secure constant airflow from an area of higher cleanliness level to an area of lower cleanliness level in order to maintain required environmental conditions of clean areas. 1. Pressure difference between the APA and indirect support areas should be adequately defined, monitored, and controlled

Cont. 2. Air locks should be established between the APA and indirect support areas and pressure difference between these areas should be maintained at a level sufficient to prevent the reversal of defined pressure difference or airflow. (+ve pressure inside the critical room) For example, a desired pressure difference between areas, when both closed, should be at least 10 to 15 Pa. The air lock design should meet requirements. An appropriate pressure difference should be established and maintained between indirect support areas of different cleanliness levels.

3. Airflow in the critical area (Grade A) should be unidirectional and supplied at velocity and uniformity sufficient to swiftly remove airborne particles away from the critical area. Airflow should also be supplied with sufficient care so as not to create reverse currents from adjacent areas (direct support areas, Grade B) into the critical area to prevent contamination. When conventional clean benches and RABS are used, the recommended mean flow rate is 0.45 m/sec ± 20%. Lower flow rate may be necessary depending on the type or usage of isolator system. Proper design and control should prevent turbulence or stagnant air in the aseptic processing line or clean area.

4. Wherever pressure difference is an essential part of sterility assurance, it is recommended to continuously monitor pressure difference between areas and install an alarm system to enable prompt detection of abnormal pressure differences. 5.The airflow requirements should be verified by appropriate method of validation by smoke test or other qualification tests at the installation of airflow equipment. Similar validation is also necessary when airflow patterns are changed or suspected of being changed.

6. An appropriate air change rate should be established by evaluating the potential of product contamination for individual processing areas and gowning rooms in the APA to maintain air cleanliness at specified levels. The generally recommended air change rate is 30 times per hour in the direct support area and 20 times per hour in Grade C work rooms among indirect support areas. These change rates should be monitored at regular intervals to verify that the rates are continuously maintained as specified. Air current should be controlled not to ascend to prevent deterioration of work environment due to dust and bacteria stirred up from the floor. The most common method of securing downward current is to install supply vents close to the ceiling and exhaust vents close to the floor.

7. Changes in flow velocity can alter flow direction when airflow is specified to be unidirectional. The velocity should be confirmed to be constant at a predetermined level by monitoring the velocity of airflow from HEPA filters at time intervals specified in the program. 8. The cleanliness of the work room must be promptly returned to the non-operating level after completion of processing and workers leave the room. In the direct support area, airborne particle count should preferably be returned to the non-operating count in 15 to 20 minutes

9. Intended differential pressure and airflow patterns during processing should be specified and documented and then validated to be suitable and appropriate for commercial manufacture. The impact of turbulence created by the movement of personnel on the cleanliness of the manufacturing environment should be evaluated, and evaluation results should be reflected in relevant SOPs. 10. It is necessary that the critical area be cleaned most often with the best cleaning ability without introducing contamination.

PERSONNEL - minimum number of personnel - initial and regular training (hygiene , microbiology) - the processing of animal-tissue materials or of cultures of microorganisms. - high standards of personal hygiene and cleanliness are essential. - periodic health checks

- Outdoor clothing should not be brought into clean areas Wrist-watches and jewellery The clothing required for each grade is as follows:   • Grade D. The hair and, where relevant, beard and moustache should be covered. Protective clothing and appropriate shoes or overshoes should be worn. Appropriate measures should be taken to avoid any contamination from outside the clean area.

Grade C. The hair and, where relevant, beard and moustache should be covered. A single or two-piece trouser suit, gathered at the wrists and with a high neck, and appropriate shoes or overshoes should be worn. The clothing should shed virtually no fibres or particulate matter.  

Grades A/B. Headgear should totally enclose the hair and, where relevant, beard and moustache. A single or two-piece trouser suit, gathered at the wrists and with a high neck, should be worn. The headgear should be tucked into the neck of the suit. A face mask should be worn to prevent the shedding of droplets. Appropriate, sterilized, non-powdered rubber or plastic gloves and sterilized or disinfected footwear should be worn. Trouser-bottoms should be tucked inside the footwear and garment sleeves into the gloves. The protective clothing should shed virtually no fibers or particulate matter and should retain particles shed by the body.  

Outdoor clothing should not be brought into changing rooms leading to grade B and C rooms. For every worker in a grade A/B room, clean sterilized or adequately sanitized protective garments should be provided at each work session, or at least once a day if monitoring results justify this. Gloves should be regularly disinfected during operations. Masks and gloves should be changed at least at every working session. The use of disposable clothing may be necessary.  

Clothing used in clean areas should be laundered or cleaned in such a way that it does not gather additional particulate contaminants that can later be shed. Separate laundry facilities for such clothing are desirable. If fibers are damaged by inappropriate cleaning or sterilization, there may be an increased risk of shedding particles. Washing and sterilization operations should follow standard operating procedures.

Premises All premises should as far as possible be designed to avoid the unnecessary entry of personnel. Grade B areas should be designed such that the operations are visible from outside. In clean areas, all exposed surfaces should be smooth, impervious and unbroken in order to minimize the shedding or accumulation of particles or microorganisms and to permit the repeated application of cleaning agents and disinfectants where used.  

To reduce the accumulation of dust and to facilitate cleaning, there should be no uncleanable recesses and a minimum of projecting ledges, shelves, cupboards and equipment. Doors should be carefully designed to avoid uncleanable recesses; sliding doors are undesirable for this reason. False ceilings should be sealed to prevent contamination from the space above them.   Pipes and ducts should be installed so that they do not create recesses which are difficult to clean.

Sinks and drains should be avoided wherever possible and should be excluded from areas where aseptic operations are carried out. Where installed they should be designed, located, and maintained so as to minimize the risks of microbial contamination; they should be fitted with effective, easily cleanable traps with air breaks to prevent back-flow. Any floor channel should be open, easily cleanable and be connected to drains outside the area in a manner which prevents entry of microbial contaminants.

Changing rooms should be designed as airlocks and used to provide separation of the different stages of changing, so minimizing microbial and particulate contamination of protective clothing. They should be effectively flushed with filtered air. The use of separate changing rooms for entering and leaving clean areas is sometimes desirable. Hand-washing facilities should be provided only in the changing rooms, not in areas where aseptic work is done.

Airlock doors should not be opened simultaneously Airlock doors should not be opened simultaneously. An interlocking system and a visual and/or audible warning system should be operated to prevent the opening of more than one door at a time. The utilization of absolute-barrier technology and automated systems to minimize human interventions in processing areas can produce significant advantages in ensuring the sterility of manufactured products. When such techniques are used, the recommendations in this section, particularly those relating to air quality and monitoring, still apply, with appropriate interpretation of the terms "work station" and "environment".  

Equipment 1- A filtered air supply should maintain a positive pressure relative to surrounding areas under all operational conditions and flush the area effectively 2- air flow patterns do not present a contamination risk, e.g. care should be taken to ensure that air flows do not distribute particles from persons, operations, or machines to zones of higher product risk.  

warning system should be included to indicate failure in the air supply restricting unnecessary access to critical filling areas, e.g. grade A filling zones, by the use of a physical barrier. A conveyor belt should not pass through a partition between a clean area B and a processing area of lower air cleanliness, unless the belt itself is continuously sterilized (e.g., in a sterilizing tunnel).

Equipment used for processing sterile products should be chosen so that it can be effectively sterilized by steam or dry heat or other methods. Equipment fittings and services should be designed and installed so that operations, maintenance and repairs can be carried out outside the clean area. If the equipment has to be sterilized, it should be resterilized after complete reassembly.  

When equipment maintenance is carried out within the clean area, clean instruments and tools should be used, The area should be cleaned and disinfected where appropriate before processing recommences, if the required standards of cleanliness and/or asepsis have not been maintained during the maintenance work.

Water treatment plants should be designed, constructed and maintained so as to ensure the reliable production of water of an appropriate quality. They should not be operated beyond their designed capacity. Water should be produced, stored and distributed in a manner which prevents microbial growth.

Filtration of Pharmaceutical Products which Cannot be Sterilized in Their Final Container Certain solutions and liquids that cannot be sterilized in the final container can be filtered through a sterile filter of nominal pore size 0.22 micron (or less), or with at least equivalent microorganism retaining properties, into a previously sterilized container. Such filters can remove bacteria and moulds, but not all viruses or mycoplasmas. Consideration should then be given to complementing the filtration process with some degree of heat treatment.  

Due to the potential additional risks of the filtration method as compared with other sterilization processes, a double filter layer or second filtration via a further sterilized microorganism-retaining filter immediately prior to filling may be advisable. The final sterile filtration should be carried out as close as possible to the filling point.  

Fiber-shedding filters should not be used Fiber-shedding filters should not be used. The use of asbestos-containing filters should be absolutely excluded. The integrity of the filter should be checked by an appropriate method such as a bubble point test immediately after each use (it may also be useful to test the filter in this way before use). The time taken to filter a known volume of bulk solution and the pressure difference to be used across the filter should be determined during validation and any significant differences from this should be noted and investigated. Results of these checks should be recorded in the batch record.  

The same filter should not be used for more than one working day unless such use has been validated. The filter should not affect the product by removal of ingredients from it or by release of substances into it.

Finishing of sterile products 1 Containers should be closed by appropriately validated methods. Samples should be checked for integrity according to appropriate procedures. 2 Containers sealed under vacuum should be sampled and the samples tested, after an appropriate predetermined period, to ensure that the vacuum has been maintained.

Filled containers of parenteral products should be inspected individually. When inspection is done visually, it should be done under suitable and controlled conditions of illumination and background. Operators doing the inspection should pass regular eyesight checks, with spectacles if worn, and be allowed frequent breaks from inspection. Where other methods of inspection are used, the process should be validated and the performance of the equipment checked at intervals. The results should be recorded.