Antibodies, also known as immunoglobulins (Ig), are glycoproteins that can specifically bind to antigens. Common antibodies include monoclonal antibodies, bispecific antibodies, polyclonal antibodies, and ADC, FC fusion proteins. In the whole production process of antibodies, in order to make production progress quick and reduce the construction cost of common works, almost all production lines prefer to use single-use systems. For example, the preparation and filtration of culture media, cell cultivation and harvesting, clarification, buffer preparation and filtration, ultrafiltration concentration and fluid exchange, purification chromatography, formulation filling, etc.
Application of Single-use Systems in the Antibody Production
Application of Single-use Systems in the Upstream of Antibody Production
1. Preparation, filtration, and storage of culture medium
2. Cell culture
3. Sampling of fermentation broth
4. Harvesting of fermentation broth
5. Harvesting after Centrifuge or depth filtration
Application of Single-use Systems in the Downstream of Antibody Production
1. Buffer preparation, filtration, and storage
2. Virus inactivation and clarification filtration
3. Purification chromatography and material harvesting
4. Virus removal, sampling, and material harvesting
5. Ultrafiltration concentration and liquid change
6. Sterile sampling process
Among them, the chromatography process is the most time-consuming and laborious in production due to the disinfection, balance, rinsing, elution, liquid exchange, and other operations. However, the use of a single-use system for liquid preparation, storage, and chromatography harvesting greatly improves production efficiency and optimizes the production process.
Chromatography Process:
01 Preparation Process
Suitable liquid dispensing systems can be matched based on buffer volume and process operation quantity. There are more than 17 types of buffer solutions in the 2000L process, mainly consisting of 1000L disinfectant buffer, 2000L equilibrium buffer, 1000L wash buffer, 1000L elution buffer, and 500L preservation buffer, with a three-step chromatography. During the preparation process, real-time monitoring of pH, conductivity, and other data can be achieved through the online electrode of the single-use system, completing the data monitoring process of online liquid preparation and recording the data.
02 Preparation Completed, Filtration Process
Multiple materials such as PES, PVDF, single layer, double layer, modified, etc. can be flexibly selected for capsule filters. They are pre-assembled with the preparation and collection system, and the entire component completes irradiation sterilization. They are ready to use after unpacking, eliminating the need for filter sterilization and assembly operations. It reduces labor costs and also reduces risks such as misoperation and bacterial contamination during the operation process, greatly improving safety.
03 Chromatographic Column Processing and Sampling
Compared to stainless steel systems, the pipes of a single-use system are shorter, reducing the volume of buffer used for exhaust during operation. Membrane chromatography is also a technological trend that replaces traditional column chromatography, with the advantages of simple operation and high loading capacity. The pore size distribution is wide, not affected by molecular size and flow rate, and the efficiency is high.
04 Intermediate Product Harvest
The chromatography harvesting process can directly connect the chromatography system outlet to the mixing bag, so mixing can start during the harvesting process. The system is also equipped with a temperature control sleeve. If the temperature needs to be 2-8 ℃, the sleeve TCU or cooling water circulation can be activated. It can be stored or transferred to the next stage according to the process time requirements. Of course, the method of membrane chromatography will make production more convenient, integrating the capsule filter and harvesting system without other operations.
The harvesting system is movable, reducing the length of the pipeline, and greatly reducing the residual liquid in the system and pipeline. It can achieve residual liquid control of 1% or less, saving costs and avoiding waste.
05 Combined Use of Ultrafiltration System
The single-use liquid dispensing system replaces the traditional ultrafiltration system buffer tank. Compared with the stainless-steel system, the single-use system is designed with a bottom drain, which allows for more thorough drainage, shorter pipelines, and smaller circulating dead volume. At the same time, the automatic control unit of the single-use mixing system can be integrated into the control unit of the ultrafiltration system, further reducing hardware investment and making the operation easier and more convenient.
Application of single-use systems in antibody production formulations.
1. Dosage Preparation
2. Filtering and Filling
The preparation stage focuses on the relationship between cleanliness and system design and operation, usually involving the sterile transfer of materials and liquids across rooms, whereas filling emphasizes more on the filling pipeline, filling needle and liquid properties, equipment matching, and ultimately confirmed from the stability of the filling volume.
