Conductivity measurement according to USP<645> Automation increases reliability and productivity





Measuring the conductivity

of pure water using USP<645> 02

Pure water is important for our health and it is critical for Metrohm offers a fully automated solution for this pharmaceutical products. The requirements for purified measurement according to USP<645>. This solution water quality are especially high when it is used in such reduces the risk of human error increasing the reliability cases for injections, as diluent for active ingredients, or as of results.

sterile water.

USP<645> defines a 3-stage test procedure Conductivity measures the purity of the water used in the For the stage 1 testing the conductivity and tempera-pharmaceutical, biopharmaceutical, and microbiology ture are measured. If the conductivity is lower at the sectors. It analyzes the amount of ions dissolved in the mea sured temperature than the stipulated value, the test sample. Conductivity is an important quality parameter is passed.

of purified water, and its measurement is stipulated in several standards, such as USP general chapter <645>.

If not, stage 2 testing has to be carried out. The water is temperated in an open vessel to 25 °C while stirring it USP<645> describes a three stage procedure to measure to obtain a CO equilibrium. The conductivity is measured.

2

conductivity of pure water and water for injec tion.

If the conductivity is higher than 2.1 μS/cm, testing according to stage 3 must be performed.

Stage 1

During the stage 3 testing a small amount of KCl is added to the sample to ensure a stable pH value. The measured conductivity in step two has to be lower than a stipulated limit for the measured pH value. If this value Measured conductivity

yes

is exceeded, the testing failed, and the sample is not below stipulated value at

Water ok

compliant.

measured temperature?

no

Stage 2

yes

Measured conductivity

Water ok

below 2.1 µS/cm?

no

Stage 3

pH between 5.0 and 7.0

yes

and measured conductivity

Water ok

below stipulated value at

measured pH?

no

Water not ok

Schematic of 3-stage analysis Metrohm MATi 14 dedicated for conductivity measurements according to USP<645> according to USP<645>.

in up to 28 samples.



Automation reduces risks

Conductivity measurement according to USP<645> Easy to use – How does automated water 03

re

quires precise and thorough working, if the conductivity measurment work?

measurement is performed manually. Measurement or After filling the water into the sample beakers and cov-evaluation errors can result in batch recjections or even a ering them, the system carries out the measurement production stop.

completely unattended. The evaluation, if the sample fulfills the requirements of USP<645> and after which stage, is automatically displayed.

The complete system is controlled by tiamo TM, which allows you to work fully compliant with regulatory standards such as FDA 21 CFR Part 11.



More safety through automation and data integrity

Using Metrohm’s automated system for measuring water conductivity according to the USP norm not only reduces the riks of operator errors. System control by tiamo TM

ensures data integrity and compliance with regulatory standards such as FDA 21 CFR Part 11.

Increase productivity

Automated conductivity testing frees up laboratory staffs, time and increases sample throughput.

Literature

USP<645>, Water Conductivity Metrohm Application Bulletin AB-428, Automatic conductometry in water samples with low electrical conductivity in accordance with USP<645> https://www.metrohm.com/en/applications/AB-428

www.metrohm.com

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G, CH-9100 Herisau, S

ohm A

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