According to on-site inspection reports from the Vietnam Drug Administration, over 35% of critical deficiencies during factory audits are directly related to cross-contamination control at transit warehouses. This poses a significant challenge for Warehouse Managers and Production Directors when opening packaging that is directly exposed to air.

Establishing a standardized raw material sampling area is a mandatory technical safeguard to protect the purity of incoming raw materials. This process requires close coordination between physical space separation solutions and aerodynamic systems.

This article will provide an optimal solution for planning a closed sampling room and internationally standardized field testing equipment. From this, we can easily complete audit documentation and operate warehouses safely.

1. Planning the Location of the Closed Sampling Room

1.1 Principle of Placing the Sampling Room Adjacent to the Raw Material Warehouse

The core principle in GMP-compliant warehouse design stipulates that sampling must be carried out in a strictly controlled, isolated area. Planning the sampling room to be adjacent to or inside the raw material warehouse minimizes the travel distance of uncleared raw material packages. This approach eliminates the risk of contamination from the external environment with dust and dirt when the raw material packaging is opened.

We need to establish specialized sampling rooms for different groups of raw materials. For example, the sampling room for cosmetics and the sampling room for topical medications must be arranged separately and enclosed to absolutely prevent cross-contamination.

1.2 Setting up a Mechanically Locked Changing Room

Personnel must undergo a cleaning and changing process before accessing the sampling booth. We need to set up a changing room (P. Changing Room) that acts as a physical airlock.
The doors in the changing room are equipped with an interlocking mechanism to prevent both doors from opening simultaneously. This prevents unfiltered air from the raw material warehouse corridor from directly entering the sterile sampling booth and causing contamination.

2. Controlling Airflow in the Sampling Booth

2.1 Negative Pressure Differential Mechanism to Prevent Coarse Dust Dispersal

When sampling powdered raw materials, the mechanical force can easily disperse fine dust particles into the air. To completely eliminate this phenomenon, the sampling booth must be maintained in a slightly sloping negative pressure state.
The standard differential pressure index needs to be controlled to fluctuate between -10 Pa and -15 Pa relative to the raw material storage corridor. This pressure slope creates a forced inward mechanical suction force, keeping all fine powder particles within the filter area. This aerodynamic principle prevents the risk of dust spreading to adjacent storage areas.

2.2 Vertical Laminar Airflow Velocity

The unidirectional laminar airflow, directed from the ceiling of the booth down to the floor, plays a role in mechanically separating suspended pollutants. According to the international standard ISO 14644-1, the airflow velocity must be strictly maintained within the range of 0.36 m/s to 0.54 m/s.
The integrated filtration system includes HEPA H14 filters with a minimum dust removal efficiency of >= 99.995% for particles of 0.3 µm size. This fluid flow continuously sweeps through the sampling area with a 90% air recirculation rate and only 10% is discharged through the secondary membrane to maintain a stable pressure differential.

3. Applications of Mobile Sterile Culture Cabinets

3.1 Sterile Dust Mat Configuration of LK Lab Cabinet Class 100

For sampling sensitive liquid excipients or biological test samples, we need a mobile sterile filtration system. The LM-1800V microbiological culture cabinet supplied by Duc Duong is the ideal device for this control process in the warehouse.
The product synchronizes technical data directly from the manufacturer’s portal, LK Lab Korea. The cabinet’s vertical laminar airflow mechanism creates an absolutely sterile working area achieving Class 100. The high-performance HEPA filter completely eliminates the risk of biological contamination of liquid samples by the breath of the testing technician.

3.2 Short-Wave UV Sterilization Cycle

To enhance the reliability of the sampling process, the LK Lab culture cabinet incorporates a 253.7 nm short-wavelength UV sterilization lamp. The control system allows setting the sterilization irradiation time of the work chamber before the start of the machine shift.
The specially designed tempered glass frame completely prevents ultraviolet radiation from escaping. This mechanical design provides absolute biological and mechanical safety protection for the tester throughout the preparation process.
If you are looking for a Sampling Booth layout solution and a complete GMP-standard sampling room equipment package, please click on the Contact Duc Duong Registration Form to receive a cleanroom layout drawing and a detailed price quote from our project engineers.

The LM 1800V microbiological culture cabinet, distributed by Duc Duong, is used in raw material sampling areas for GMP-certified manufacturing plants

4. Rapid Measurement of Raw Material Moisture Content

4.1 Application of Kett FD-660 Moisture Analyzer for Rapid Field Analysis

The moisture content of powdered raw materials directly affects the physicochemical stability and shelf life of semi-finished products. We need to equip ourselves with the Kett FD-660 infrared moisture analyzer to quickly measure moisture content immediately upon opening the packaging at the sampling booth.
The product is imported directly from the manufacturer Kett Japan. The device uses radiant heat from high-power quartz infrared lamps to uniformly dry raw samples. The analysis time is optimized to under 15 minutes, helping to promptly handle batches of excipients that are damp or clumpy before warehousing.

The Kett FD 660 infrared moisture analyzer is used in the raw material sampling area for GMP manufacturing plants

4.2 Kett FD-800 High-End Moisture Analyzer with GLP Data Tracking

For factories requiring measurement data management according to Good Laboratory Practice (GLP) standards, the Kett FD-800 infrared moisture analyzer is the optimal upgrade solution. The product specifications are officially synchronized with the Kett Japan website.
The machine features an automatic sample surface temperature sensor that continuously adjusts the drying intensity and boasts an extremely high weighing resolution of up to 0.01%. The system supports connection to a dedicated thermal printer, allowing for on-site moisture measurement results for record-keeping purposes.

The Kett FD 800 infrared moisture analyzer is used in the raw material sampling area of ​​GMP-certified manufacturing plants

5. Standard Procedures for Liquid Sampling

5.1 SOP for Operating a 90-Degree Vertical Micropipette

Sampling of concentrated liquid excipients or crude solvents requires very high volume accuracy. To completely eliminate systematic errors, the tester must strictly adhere to the 17 points to note when using a micropipette compiled by Duc Duong.
The standard SOP requires always keeping the pipette body vertical at a 90-degree angle throughout the sampling process. The plastic tip must be immersed 2 mm to 4 mm below the surface of the crude liquid. This procedure ensures even capillary force distribution, preventing sample volume deviations.

5.2 Specialized Reverse Pipetting Technique for Viscous Liquids

High-viscosity materials such as glycerin, crude coconut oil, or volatile solvents often cause significant wetting on the inner wall of the plastic tip. We must apply the reverse pipetting technique to handle this group of samples. The mechanical mechanism of this method is to press the piston past the first to the second discharge position before aspirating the sample. When discharging the liquid, we only press it to the first position to fully compensate for the volume loss due to the adhesive force of the liquid.

6. Equipment Calibration Schedule at the Warehouse

6.1 Calibration Cycle of Kett Infrared Moisture Analyzers

To maintain reliability and traceability for rapid field measurements, the Kett FD-660/FD-800 moisture analyzer system requires rigorous maintenance. We establish a calibration cycle for the weights and temperature sensors every 6 to 12 months according to ISO/IEC 17025 standards.
In addition, the QA department needs to develop a procedure for cleaning the drying disc with a specialized soft brush after each operating shift. This activity prevents coarse dust from adhering to the force sensor, causing weight drift errors.

6.2 Mid-term Self-Check Procedure using Moisture Standard Samples

The monthly intermediate check acts as a barrier to detect early degradation of the quartz heating element’s performance. We use a theoretical moisture standard sample of sodium tartrate dihydrate with a standard moisture content of 15.66% ± 0.05%.

This self-assessment helps control sensor drift errors and maintain the integrity of measurement data. Equipment calibration logs need to be digitized and stored securely for easy presentation during unscheduled GMP inspections.

Conclusion

Infrastructure planning and installation of measurement equipment in the raw material sampling area is a core link determining the quality of the entire production chain. The design of a closed sampling room adjacent to the warehouse, the use of negative pressure control in the sampling booth to prevent free-flowing dust, the application of LK Lab sterile culture cabinets combined with Kett infrared moisture analyzers from Japan, standardized micropipette operation, and a regular ISO 17025 calibration schedule all aim to completely eliminate the risk of cross-contamination. At the same time, these solutions also strongly support the factory in easily passing rigorous assessments according to international GMP standards for cosmetics and pharmaceuticals. Duc Duong Company is proud to be a reputable general contractor, providing comprehensive solutions for the design and construction of sampling booths and equipping high-quality laboratory equipment.

If your company requires consultation on designing a standard sampling booth layout or a complete quote for a genuine microbiological culture cabinet and infrared moisture analyzer system, please contact and leave your information at DUC DUONG SCIENCE AND TECHNOLOGY COMPANY to receive the most in-depth support from our project engineering team.

 

DUC DUONG SCIENCE AND TECHNICAL COMPANY

Address: 1014/67 Tan Ky Tan Quy, Binh Hung Hoa, Binh Tan, HCM

Tel: (028) 3762 8042 – 3762 8043 – 3750 8514 – 3750 8793

Fax: 028 37628043

Email: ducduong@ducduongco.com

Website: ducduongco.com

ZALO OA: DUC DUONG SCI

 

FAQ

1. Why does the GMP standard require the design of a negative pressure sampling booth?

When opening raw material packaging containing fine powder, ultrafine dust particles easily float freely into the warehouse air. A negative pressure sampling booth design, ranging from -10 Pa to -15 Pa, creates a forced inward suction force. This aerodynamic airflow forces all the fine dust particles into the HEPA filter, completely preventing the risk of coarse dust spreading and causing cross-contamination to adjacent storage areas, and protecting the respiratory safety of the inspectors.

2. What is the difference between sampling in a Laminar flow sampling booth and a mobile sterile culture cabinet?

A vertical Laminar flow sampling booth has a spacious working area, suitable for direct sampling from large packages and pallets placed on the floor of the raw material warehouse. Conversely, the LM-1800V mobile sterile microbiological culture cabinet is a compact, self-contained filter chamber placed on a table. This device is optimized for the separation and quantification of small-volume liquid samples and sensitive biological samples requiring a sterile substrate with an absolute Class 100 rating, free from contamination from human breath.

3. How does the Kett FD-800 infrared moisture analyzer operate to shorten measurement time to under 15 minutes?

The Kett FD-800 moisture analyzer uses radiant heat from high-power quartz infrared lamps directly impacting the surface of the raw sample. Infrared radiation stimulates the kinetic energy of free water molecules, causing continuous evaporation without altering the chemical nature of the material. The integrated weight sensor continuously records the mass loss and automatically calculates the percentage of moisture content, displaying it directly on the LED screen, allowing technicians to make on-site decisions regarding customs clearance of the shipment.

4. How is the reverse pipetting technique using a micropipette performed to avoid errors in viscous liquid samples?

In the reverse pipetting technique, the technician presses the piston button past the first to the second dispensing position, then dips the plastic tip into the viscous liquid and slowly releases the button to draw up the entire solution. When dispensing the sample into the receiving cup, the piston is only pressed to stop at the first position. A small amount of sample remaining and adhering to the inside of the plastic tip is removed along with the tip, completely compensating for volume errors due to mechanical wetting.

5. What should be considered regarding the installation environment of the infrared moisture analyzer in the warehouse area of ​​a manufacturing plant?

Warehouse environments are always subject to significant mechanical vibrations from forklifts and pallets and contain a lot of dust. Therefore, the Kett infrared moisture analyzer must be placed on a sturdy laboratory table, completely isolated from machinery with strong vibrating motors. At the same time, the moisture analyzer should be placed away from direct airflow from the HVAC system to avoid causing vibrations in the sensor plate, and the quartz drying plate should be cleaned of fine dust after each measurement cycle.