Balances for Analytical Purpose aims to ensure the quality control of medicines in European member states. The requirements of the Ph. Eur. Are similar to the General Chapter 41 of the United States Pharmacopoeia (USP).
Last Update 23/09/2022
The new chapter was published in July 2021 and entered into force on January 1, 2022.
During calibration, a relationship is established between the known values of the certified test weights and the values measured by the balance. Chapter 2.1.7 states that “... the instruments must be periodically calibrated [...] by the user or by a suitable competent body”. There are three requirements established in the Ph.Eur. (2.1.17):
The calibration of an instrument according to the Eu.Ph. (2.1.7) must be performed by an accredited center. The Gibertini 17025 calibration service guarantees competence through its LAT094 accreditation.
A test load not exceeding 5% of the maximum capacity of the balance, or at least equal to 100 mg, is used to check the repeatability. The weight is placed 10 times on the weighing pan, zeroing the instrument before each measurement.
Per il calcolo della sensibilità, viene posto un peso certificato compreso tra il 5% e il 100% della portata della bilancia e viene rilevata l'indicazione.
The smallest possible sample weight on a laboratory balance is related to the minimum weight (R), which is 2000 times the standard deviation. Therefore, if the calculated standard deviation turns out to be s = 0.25 mg, the minimum weight will be R = 500 mg.
Below is the table of the minimum possible weights for the Crystal analytical balance
|Model||Capacity||Division||Minimum Weight (Rmin)|
|CRYSTAL 100 CAL CE||110 g||0.1 mg||82 mg|
|CRYSTAL 200 CAL CE||210 g||0.1 mg||82 mg|
|CRYSTAL 300 CAL CE||310 g||0.1 mg||82 mg|
|CRYSTAL 500 CAL CE/C||510 g||1 mg||820 mg|