THE EUROPEAN DIRECTORATE FOR THE QUALITY OF ......Use of Ph.Eur. Reference Standards Establishment of Reference Standards Manufacturing, Labelling, Storage and Distribution of Ph.Eur

THE EUROPEAN DIRECTORATE FOR THE QUALITY OF MEDICINES & HEALTHCARE (EDQM)

2 ©2020 EDQM, Council of Europe. All rights reserved.

Establishment and use of Ph. Eur. Reference standards

Dr. Bart BlanchaertLaboratory Department

EDQM, Council of Europe

EUROPEAN PHARMACOPOEIA TRAINING7-8 July 2020, Webinar


Outline

Terms and definitions

Establishment and use

RS for finished products monographs

RS for general methods





Terminology Use of Ph.Eur. Reference Standards Establishment of Reference Standards Manufacturing, Labelling, Storage and Distribution of Ph.Eur Reference Standards Re-Test Programme of Ph.Eur. Standards


ISO GUIDE 30 / Ph.Eur. 5.12.

Reference MaterialMaterial, sufficiently homogeneous and stable with respect to one ormore specified properties*, which has been established to be fit forits intended use in a measurement process.

* quantitative or qualitative




Certified Reference Material (CRM)Reference material characterized by a metrologically valid procedurefor one or more specified properties, accompanied by a certificatethat provides the value of the specified property, its associateduncertainty, and a statement of metrological traceability.




Primary measurement standardA standard designated or widely acknowledged as having the highestmetrological qualities and whose property value is acceptedwithout reference to other standards of the same property orquantity, within a specific context.

Secondary measurement standardStandard whose property value is assigned by comparison with aprimary standard of the same property or quantity.



Ph.Eur. 5.12.

Reference Standard (RS)General term covering reference substances, preparations and spectra.

European Pharmacopoeia reference standard (Ph.Eur. RS)A reference standard established under the aegis of and adopted bythe European Pharmacopoeia Commission.



Ph.Eur. 5.12.

European Pharmacopoeia chemical reference substance (CRS)Substance or mixture of substances intended for use as stated in amonograph or general chapter of the European Pharmacopoeia.

Note: HRS and BRP are other types of RS.



EUROPEAN PHARMACOPOEIACOMPENDIAL STANDARD = MONOGRAPH + REFERENCE STANDARD

Method Specifications

Reference standard

Marketing AuthorisationCertification

Directives 2001/83/EC and 2001/82/EC



Ph.Eur. General Notices

The European Pharmacopoeia Commission establishes the officialreference standards, which are alone authoritative in case ofarbitration.

These reference standards are available from EDQM.

REFERENCE STANDARDSLEGAL ASPECTS



EU guideline for GMP * Part 1 – 6.20Whenever compendial reference standards from an official source exist,these should preferably be used as primary reference standards unless fullyjustified (the use of secondary standards is permitted once their traceability toprimary standards has been demonstrated and is documented).These compendial materials should be used for the purpose described in theappropriate monograph unless otherwise authorised by the National CompetentAuthority.

* Eudralex Volume 4, EU guidelines for good manufacturing practice for medicinal products for human and veterinary use

REFERENCE STANDARDSLEGAL ASPECTS



Establishment and use


?RS for identification


Identification of substances subject of a Ph. Eur. monograph

Infrared absorption spectrophotometry (IR) , CRS or Ph. Eur. Reference Spectrum

Nuclear magnetic resonance spectrometry (NMR), if spectrum cannot be interpreted

Chromatographic separation techniques (LC, GC, TLC)

RS for identification


Example IR



Example TLC



Example NMR



EstablishmentKey quality attribute= identity

Identity: full structural elucidation (NMR, TOF-MS)

Compliance with relevant requirements of the monograph

Intended use

Characterisation less elaborated than for RS used quantitatively



Assay RS


Mostly used as external standard in LC or GC method

Substance compliant with relevant requirements of corresponding Ph.Eur. monograph

Exceptional cases: other salt form, other hydrate, lyophilised RS

Content is assigned based on mass balance approach (compendial + complementary tests)

Uncertainty of the assigned value is evaluated and shall be negligible compared to content limits in the monograph

Assay RS


Assay RS


EstablishmentKey quality attributes: Identity and content

Identity: full structural elucidation

Compliance with relevant requirements of the monograph

Volatile impurities (LOD, residual solvents (HS-GC) and water)

Inorganic impurities (sulfated ash)

Assay RS


Establishment (continued) Homogeneity (LOD or water, residual solvents in specific cases)

Confirmation of assigned content by orthogonal methods (DSC, qNMR, elemental analysis)

Inter-laboratory study for parameters with significant contribution to assigned content

Assay RS


Example: Raltegravir potassium CRS 1

Assay RS


Example: Raltegravir potassium CRS 1Characterisation EDQM Lab

Test Result RSD nAppearance Almost white powder n/a 1

Mass spectrometry(in-house method)

2.2.43.m/z found in accordance with

sum formula n/a 1

Nuclear magnetic resonance spectrometry

(in-house method)2.2.33.

NMR spectra in accordance with structure n/a 1

Identification reactions of ions and functional groups

2.3.1.Positive reaction b) of

potassium n/a 1

Infrared absorption spectrophotometry

2.2.24.KBr disc and ATR spectra

recorded n/a 1

Related substances by liquid chromatography2.2.29. / 2.2.46.

See inter-laboratory study - -

Semi-micro determination of water2.5.12.

See inter-laboratory study - -

Test Result RSD n

Micro determination of water2.5.32.

0.16 % sd: 0.02 8

Conditions: Direct introduction of about 50 mg - -

Residual solvents by headspace gas chromatography

2.2.28. / 2.4.24.

Acetonitrile and ethanol:see inter-laboratory study

Sum of other residual solvents: below 0.10 %

(Traces of toluene detected)

- -

Quantitative nuclear magnetic resonance spectrometry (in-

house method)2.2.33.

About 99.4 % n/a 3

Internal standard: maleic acid - -

Elemental analysisC: 49.8 % (theory 49.8 %)H: 4.2 % (theory 4.2 %)

N: 17.4 % (theory 17.4 %)n/a 3

Assay RS


Example: Raltegravir potassium CRS 1LC suitability

Assay RS


Example: Raltegravir potassium CRS 1LC results

Assay RS


Example: Raltegravir potassium CRS 1

(100 % - water % - residual solvents %) x [(100 % - sum of impurities by LC %) / 100 %] =

99.1 % of C20H20FKN6O5

Content assignment

Assay RS


RS for impurity control


Qualitative RS in impurity control

Chromatographic separation techniques (LC, GC, TLC)

Batch testing: identification of signals (specified impurities or CF)

System suitability testing (no batch related results generated)

Similarities in establishment

RS for impurity control (qualitative)


Type of RS Pros Cons

Single substanceStability

Concentration easily controlledBatch continuity

May result in high number of RSAvailability

Mixture Representative of what user observes RS batch continuityPeak saturation for API







RS for impurity control (qualitative)RS strategy Single substance <-> mixtures

Alternative to RS: commercial reagent or in situ degradation

If impurities are specified production batches expected to be suitable

A chromatogram is often supplied in the RS leaflet


Establishment: single substance RS not subject of a Ph. Eur. monograph (e.g. impurity)Key quality attribute: identity

Full structural elucidation

Intended use

Characterisation is less elaborated than for RS used quantitatively



Establishment: mixture RSKey quality attributes: identity of impurities, homogeneity, fitness for

purpose

Identity of impurity peaks

Spiking with authentic impurity samples

Homogeneity

Intended use



Use Mostly in chromatographic methods

External standard for impurities with a response very different fromthat of main substance

RS for impurity control (quantitative)


Content of RS is critical: ≥ 95.0 % or not?

Salt form has impact on use need for stoichiometric conversion factor?

Single substance RS only

Non-GMP material





EstablishmentKey quality attributes: identity and content

Identity: Structural elucidation

Identity of counter-ion: specific or screening

Related substances: method of intended use (LC/GC)

Volatile impurities: Loss on drying, thermogravimetry or water (+ residual solvents)



Establishment (continued)Inorganic impurities: Sulfated ash (if amount allows) or screening

qNMR

Homogeneity: relevant parameter

Content assignment: mass balance or qNMR

Orthogonal methods



Example: Phenobarbital impurity A CRS 1Analytical resultsIdentity: confirmedLoss on drying: 0.1 %LC-purity: 99.7 %

Content by qNMR (expressed ‘as is’, as free base): 79 %Elemental analysis: does not match the theoretical composition

Investigation Identification of nitrate as the counter ion (not on CoA)Quantification of nitrate by ion-exchange chromatography: 20.6 %


Mass balance: 99.6 %No need for assigned content


RS for finished product monographs


RS for finished product monographs

Can we use the RS used in the correspondingdrug substance monographs?


RS for finished product monographs (identification)RS for identification Identity already certified

Independent of method

Use existing substance RS


RS for finished product monographs (assay)RS strategy depends on the assay and related substances methodsSame methods as substance’s monograph Use existing assay RS

with its assigned content

Different methods from substance’s monograph (assay and/or related substances)Compare selectivity

Similar: Use existing assay RS and its assigned contentNot similar: Use a different RS

One assay RS = one assigned content!


RS presented as mixturesSpecific related substances for FP (degradation products): separate

RSSame related substances in API and FP monograph: use existing RS

(Different methods add new chromatogram in leaflet)

Impurity RS (quantification)Existing RS and its assigned content can generally be used for FP

monograph, even when methods are different

RS for finished product monographs (impurity control)


RS for general chapters


RS for general chaptersReference materials with content traceable to the SI

Elemental impurity CRSChapter 2.4.20 Determination of elemental impuritiesFor accuracy testingLead solution CRS (1.00 mg/g)Cadmium solution CRS (1.00 mg/g)Mercury solution CRS (1.00 mg/g)Arsenic solution CRS (1.00 mg/g)


RS for general chaptersElemental impurity CRS


RS for general chaptersSodium aminosalicylate dihydrate for equipment qualification CRS Used for verification of equipment for2.2.32. Loss on drying2.5.12. Water: semi-micro determination2.5.32. Water: micro determination2.2.34. Thermogravimetric analysis





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THE EUROPEAN DIRECTORATE FOR THE QUALITY OF ......Use of Ph.Eur. Reference Standards Establishment of Reference Standards Manufacturing, Labelling, Storage and Distribution of Ph.Eur