Impurities Sources, Detection and Measurement HPLC-MS Analyses. Dr Courtney Milner Chemical Analysis

Transcription

1 Impurities Sources, Detection and Measurement HPLC-MS Analyses Dr Courtney Milner Chemical Analysis

2 Chemical Analysis Integrated Analytical Resource (Physical, Chemical and Microbiological) that has facilities for: Raw material / finished product testing Stability storage Stability testing Method development Method transfer and validation studies Essential similarity testing Reverse engineering Impurity identification Preservative Efficacy Testing Non Sterile and Sterile Microbiological Tests Endotoxins Testing

3 In-House Facilities Gas Chromatography / Mass Spectrometry / Headspace Liquid Chromatography (RID, DAD, UV, ELSD, Fluorescence) Ion Chromatography Capillary Electrophoresis LC-QQQ Mass spectrometers LC-TOF Mass spectrometer 300 MHz NMR spectrometer 500 MHz LC-NMR spectrometer Elemental analysis by ICP and AAS Wet (Pharmaceutical) Chemistry TOC Analyser Continuous temperature / RH monitoring On site back up generator Stability chambers at 5C; 25C/60%RH; 30C/65%RH; 30C/75%RH; 40C/75%RH; photostability (with temp/rh); customised conditions x 3

4 Impurity Origins at CA Stability / related substances peak ID Customer query of unknown Monitoring of low level known impurity

5 Where they can come from Integrated Analytical Resource (Physical, Chemical and Microbiological) that has facilities for: Raw material / finished product testing Stability storage Stability testing Method development Method transfer and validation studies Essential similarity testing Reverse engineering Impurity identification Preservative Efficacy Testing Non Sterile and Sterile Microbiological Tests Endotoxins Testing

6 Evolving MS detection Early 2000 s Single quad Ion trap ~2003 Accurate mass via bench top TOF Mid 2000 s Mainstream 3Q and QTOF

7 MS Requirements Key requirement is MS compatible mobile phase No non-volatile buffers Limit /Avoid TFA Limit / Avoid TEA Formic, acetic acid Ammonium acetate / formate /hydroxide Benefit of ELSD compatibility

8 The value of accurate mass For a C,H, N, O, formula search at around 600amu At 0.1amu (deemed unit mass) 209 possible formulas At 10ppm 13 options At 5ppm 7 options At 2ppm 2 options And we still have isotope ratios to help us If we add Cl and F to this, at 0.1amu there is over 4000 possibilities

9 Generating a formula

10 Deconvoluting the Spectra Disadvantage of Accurate Mass systems can be too much data Need to distil to a manageable view Use a tool of Molecular feature extractor Works on the 3-dimensional data set Removes noise Groups covariant mass signals Combines signals with chemical relations Create extracted compound chromatograms & spectra

11 Fragments can aid assignment MH + C 12 H 14 N 4 O 2 S Anti-bacterial drug mass/charge m/z 4-amino-N-(4,6-dimethylpyrimidin-2-yl) benzenesulfonamide Formula Measured Sulfamethazine ppm 5 digits C12H14N4O2S C12H13N C6H8N3O2S C6H6NO2S C6H10N C6H6NO C = H = N = O = S =

12 Other potential tools structure correlators Can pull information from sources such as: Chemspider PubChem ChemIndustry ChemBiofinder NIST Chem Webbook etc

13 Targeted Low Level Impurities Only when we know what we are looking for Often relevant if looking for genotoxic impurities, or cleaning validation studies Method development requires a higher level standard to develop transitions Utilise MS/MS to lower detection level and increase specificity

14 Potential of LC MS/MS 10ppt of Fentanyl in a cleaning validation S/N 5:1

15 Fraction collection / NMR If it is impossible to convert to an MS friendly Mobile phase we sometimes need to fraction collect the peak of interest and re-run Sometimes separation can t be reproduced Removes majority of non-volatile material NMR gives significant structural information that can support MS data

16 Summary Mass spectrometry is a powerful tool for impurity ID Transfer of traditional HPLC methods can provide challenges Different MS technologies are required for the different nature of impurity analysis undertaken

17 Contact Details Web chemicalanalsyis.com Phone Address Merrindale Drive Croydon Vic 3136