The white paper shares know-how in spectrophotometer calibration based on JP requirements.
The Japanese Pharmacopoeia (JP) is an official document that defines the specifications, criteria and standard test methods necessary to assure the quality of medicines used in Japan. The 17th edition of the JP comprises general chapters about drugs, analytical processes and apparatuses, official monographs, and drug reference spectra (UV Vis and IR).
JP 18 states that UV Vis spectrophotometry measures the degree of absorption of light between 200 and 800 nm by substances for identity and purity tests as well as for assay. The UV Vis spectroscopy-relevant chapters of the JP are:
- 2.24 (optical parameters of the UV Vis spectrophotometer to be checked), and
- 9.61 (recommended certified reference materials for the qualification of UV Vis spectrophotometers)
What is required for the qualification of a UV/Vis spectrophotometer?
The mandatory optical parameters for the qualification of a UV Vis spectrophotometer which are described in chapter 2.24 of the JP are
- Photometric accuracy (UV and Vis)
- Photometric precision (UV and Vis)
- Wavelength accuracy (UV and Vis)
- Wavelength precision (UV and Vis)
Chapter 9.61 includes a list of recommended CRM that shall be used for the qualification of wavelength accuracy/precision and photometric accuracy/photometric precision (PA/PR) in the UV and Vis wavelength region. The recommended filters are solid, neutral-density filters known as Japanese Certified Reference Materials (JCRM).
How shall photometric accuracy and precision be checked according to the JP?
According to JP chapter 2.24, the qualification of the photometric accuracy of a UV Vis spectrophotometer shall be pursued by measuring the appropriate JCRM xyz filter three times and assessing the measured values against the certified values. The difference between the measured transmission/absorption value and the certified standard transmission/absorption value for each individual measurement should be within a range from 1% larger than the upper limit to 1% smaller than the lower limit to obtain the relative accuracy given in the certificate.
The photometric accuracy qualification clearly demands the inclusion of the certification uncertainty in addition to the JP absorbance accuracy criteria when calculating the JCRM xyz-dependent relative absorbance accuracy limits. The calculation shown in the following includes the conversion from transmission to absorbance values:
A limits = ± -log(1-((A+B)/100))
A = 1% T, according to JP chapter 2.24
B = accuracy of the certified transmission or %T, according to the JQA certificate
This paper provides an overview of the important impacts JP18 and its supplements have on UV Vis spectroscopy, as well as practical tips and hints for effective operational qualification (OQ) to ensure compliance when using a UV/VIS Excellence spectrophotometer UV7 from METTLER TOLEDO. Download the white paper to get a deep insight into the respective materials, acceptance criteria and standard operating procedure in the JP 18.