A controlled area, often referred to as a classified area, is a sealed environment or enclosure where meticulous control over particulate contamination is maintained. Specifically, these areas adhere to predefined contamination levels, specifying the permissible number of particles per cubic meter for specific particle sizes. These controlled spaces are meticulously designed with precise management of humidity, temperature, and pressure to minimize the generation, introduction, and retention of particulate matter within their confines.
Primarily employed in the sterile pharmaceutical manufacturing sector, these controlled areas ensure minimal environmental pollutants such as airborne microbes, dust, aerosol particles, and chemical vapors. These classified rooms are instrumental in enabling the pharmaceutical industry to produce products devoid of both particulate and microbial contamination. These sterile pharmaceutical controlled rooms are equipped with HEPA filters and dehumidification systems to create moisture-free and contamination-free environments for pharmaceutical product preparation. Today, the utilization of controlled areas, also known as classified areas, in sterile product manufacturing has seen substantial growth.
The objectives of employing controlled areas in sterile pharmaceutical manufacturing are centered around preventing contamination and guaranteeing the complete sterility of preparations. These controlled environments serve to eliminate the risk of contamination from chemicals, bacteria, electrostatic charges, particles, and fibers. As sterile pharmaceutical products must not introduce undesirable elements like particles, chemicals, or bacteria to patients, the use of controlled areas, or classified areas, has become a critical quality assurance step for pharmaceutical companies. Additionally, due to the propensity of most surfaces within controlled rooms to develop and retain undesirable electrostatic charges, stringent cleaning and control measures are in place to promptly dissipate these charges.
Controlled areas in sterile pharmaceutical manufacturing are typically divided into two primary sections: the general area and the critical area. The general area is that portion of the rooms where the presence of contaminants will not directly impact the sterility of products. Nevertheless, the general area must undergo thorough cleaning and control to prevent the transfer of contaminants into the critical area.
The critical area is situated around the production point, where any contaminants could potentially gain direct access to the preparations. This critical zone is often safeguarded by localized Laminar-Flow workstations and clean benches.
To achieve complete sterilization during the manufacturing process, various stages such as component preparation, filling, and product assembly must be conducted in separate sections within the controlled area. This necessitates the division of manufacturing operations into stage-wise sterilization (at each stage) and terminal sterilization (for the finished preparations).
To attain thorough stage-wise sterilization, the controlled room must accommodate both "at-rest" and "in-operation" states. The "at-rest" state implies that production equipment in the classified room operates without the presence of personnel. Conversely, the "in-operation" state involves the execution of manufacturing processes by a specified and limited number of personnel.
Consequently, a sterile pharmaceutical company should categorize its controlled production into four levels: A, B, C, and D. Grade A is designated for high-risk operations such as the filling zone and areas where aseptic connections are made, open vials, and ampoules. These zones should feature laminar airflow systems with consistent airspeeds. Grade B serves as the background environment for grade A, allowing for aseptic preparation and filling. Grades C and D encompass classified areas that handle the less critical stages of sterile product manufacturing.