This book is engineering driven to highlight basis of design, design criteria, and assumptions to coach and guide professionals involved in learning more about sterile manufacturing engineering and in pharmaceutical and biopharmaceutical manufacturing facilities, including operational requirements. The intent of this book is to present a simplified treatise with some very specific description of aseptic processing techniques and sterilization methods.
Sterile manufacturing engineering and process validation guides (US FDA, Guidance for Industry โ Process Validation) are intended to manage risk, introduce Quality by Design (QbD), and ensure continued process reliability, consistency, and repeatability.
Sterile manufacturing guidelines are based on specific elements in the construction and installation of classified clean rooms, critical utility systems such as water for injection (WFI), solution transfer systems, powder transfer systems, and monitoring and controls, including automation of processes. Specialized technologies [1] in design of fill/finish lines of vials, cartridges, bottles for ophthalmic or otic purposes, prefilled syringes (PFSs), or ampoules, which might be filled and sealed aseptically or IV bags that are mostly terminally sterilized. In addition, considerations for personnel and material flow to prevent cross contamination are usually very well defined to separate in and out movements of sterile suites and cascading clean rooms through separate paths, including the use of pathโthrough transfer systems for material flow.
Overall, paying attention to the design, construction, and installation should focus on process flow and employ standardization of equipment and methodologies as much as possible. Building sustainable premises, equipment qualifications, cleaning validation, and sanitization requirements should be all in consideration as part of the design of pharma/biopharma processing. Similarly, process validation and periodic revalidation of manufacturing systems are all important stages and steps that need to be on wellโdefined schedules to ensure reliability of drug production [2].
The main emphasis of clean room classifications is to quantify particle limits when rooms are in operation (dynamic conditions) for nonviable particles. In addition, microbiological limits are emphasized when classified rooms are in operation for viable particles. Media fills are conducted to certify rooms for aseptic conditions of drug products. EN ISO 14644 Methodology
| Class ISO 146144โ1 (Federal Standard 209E) | Average airflow velocity, m/s (ft/min) | Air changes per hour | Ceiling coverage (%) |
| ISO 8 (Class 100,000) | 0.005โ0.041 (1โ8) | 5โ48 | 5โ15 |
| ISO 7 (Class 10,000) | 0.051โ0.076 (10โ15) | 60โ90 | 15โ20 |
| ISO 6 (Class 1,000) | 0.127โ0.203 (25โ40) | 150โ240 | 25โ40 |
| ISO 5 (Class 100) | 0.203โ0.406 (40โ80) | 240โ480 | 35โ70 |
| ISO 4 (Class 10) | 0.254โ0.457 (50โ90) | 300โ540 | 50โ90 |
| ISO 3 (Class 1) | 0.305โ0.457 (60โ90) | 360โ540 | 60โ100 |
| ISO 1โ2 | 0.305โ0.508 (60โ100) | 360โ600 | 80โ100 |
Microbiological Limits
| Recommended limits for microbial contamination |
| Grade | Air sample, cfu/m3 | Settle plate, ร 90 mm, cfu/4 h | Contact plates, ร 55 mm, cfu/plate | Glove print, 5 fingers, cfu/glove |
| A | <1 | <1 | <1 | <1 |
| B | 10 | 5 | 5 | 5 |
| C | 100 | 50 | 25 | โ |
| D | 200 | 100 | 50 | โ |
Monitoring of classified areas is continuous whether the room is in operation or not. Particles are measured through a continuous particle monitoring computerized system under measured conditions of temperature, pressure, and relative humidity. In addition, Environmental Monitoring Systems (EMS) with automated features are fitted with alarms to control alert and action levels in classified rooms limit of operation and regulatory requirements. Microbial counts are sampled and read using settling plates both at the aseptic core and equipment surroundings inside the classified clean room. Locations of these plates and frequency of sampling are based on formal risk analysis, sampling requirements, and validation protocols.
Various technologies are employed in sterile manufacturing such as Isolator technologies, Blow/Fill/Seal, aseptic customized tubing set as needed for product specifications, and ter...