With the rapid development of social economy, people put forward higher requirements for life, work and product production technology, product quality, etc., and the use of clean room purification engineering is becoming more and more extensive. How to rationally use the clean room and prevent the occurrence of errors, contamination and cross-contamination is one of the cores of GMP.

Cross-contamination refers to the contamination caused by the mixing of different types of drug ingredients through personnel, tool transportation, material transfer, air flow, equipment cleaning and disinfection, workplace cleaning, etc., or improper human, tool, material, air, etc. The flow will transfer pollutants from areas with low cleaning degree to areas with high cleaning degree, causing cross-contamination.

The material, processing precision, airtightness and management system of the equipment are all related to cross-contamination. Therefore, in addition to a reasonable layout, improving the automation level of the equipment, forming a linkage production line, reducing the number of operators, and reducing the frequency of activities of the operators are necessary measures to prevent cross-contamination.

The dust generation on the site of solid dosage forms is very large. How to prevent cross-contamination in solid preparation plants? First, the selected equipment needs protective covers and dust removal devices, and secondly, isolation measures are taken, which are divided into operating room, front room, operating room and auxiliary room.

The front room generally adopts a single room in the plane configuration, the auxiliary room is set in the non-clean area, and the inspection door is set on the side of the corridor. For example, equipment such as tablet compression, automatic packaging, and capsule dispensing can use this separation method. For monomers without dust removal auxiliary equipment and seals, such as pulverizers, pulverizers and particle packaging machines, the exhaust in the isolation area can be filtered and returned to the isolation area to form a self-circulation.

During the production process, some medicines are highly hygroscopic, and when the relative air humidity is required to be lower than 50% or even 45%, freezing and dehumidification is difficult to meet the requirements. Among many dehumidification measures, the lithium chloride rotor is more suitable for dehumidification. The dehumidifier can be installed in a clean room with special dehumidification requirements, and the purified air is used as the low-humidity protective air in the workplace to form a circulation system.

For clean rooms with different cleanliness levels, clean rooms that produce dust and harmful gases, and workplaces that discharge highly toxic media and flammable and explosive gases, a local exhaust system must be installed separately. The exhaust port of the clean room must have an anti-backflow device. The switches of air supply, return air and exhaust air should have interlocking devices.