Residual SolventsResidual Solvents
ICH Q3C Impurities: Residual SolventsContract Laboratories Perspectives
Assad J. Kazeminy, Ph.D.President and CEO of Irvine Analytical Laboratories, Inc.
Residual SolventsResidual Solvents
This Session will address the implementation of ICH Residual Solvents requirements by USP and PhEur from perspective of CRO:
Solvent ClassificationInteraction between Laboratory and API ManufacturerSelection of Methodologies
Screening methodologiesMethod ValidationRoutine vs. Qualification testing
Past Chromatographic ChallengesCase Studies
IntroductionIntroduction
• Residual solvents have had official limits in the United States as set in USP 30 <467> and by the FDA in 1997 and have been monitored by most pharmaceutical manufacturers extensively for more than two decades in both bulk and finished products.
• Residual process solvents in pharmaceutical samples are monitored using gas chromatography (GC) with either flame ionization detection (FID) or mass spectrometry. Based on good manufacturing practices, measuring residual solvents is mandatory for the release testing of all active pharmaceutical ingredients and is routinely performed on samples of process intermediates.
• On Jan 1, 2007 title of Chapter <467> will be changed to Residual Solvents.
IntroductionIntroduction
Sample introduction techniques include both static and dynamic headspace analysis, solid-phase microextraction, and direct injection of solution containing bulk drug substance or drug product into the gas chromatograph.
In conclusion, gas chromatograph-based procedures will continue to dominate residual solvent testing because of its specificity foridentification of the solvent, but the use of alternative sample introduction techniques into a gas chromatograph will continue to expand in the near future.
Classification of Residual Solvents by Risk Classification of Residual Solvents by Risk AssessmentAssessment
Solvents were evaluated for their possible risk to human health and placed into one of three classes as follows:
Class 1 solvents: Solvents to be avoided-Known human carcinogens, strongly suspected human carcinogens, and
environmental hazards. Class 2 solvents: Solvents to be limited-Nongenotoxic animal carcinogens or possible causative agents of other
irreversible toxicity such as neurotoxicity or teratogenicity. Solvents suspected of other significant but reversible toxicities.
Class 3 solvents: Solvents with low toxic potential-Solvents with low toxic potential to man; no health-based exposure limit is
needed. Class 3 solvents have PDE's of 50 milligrams (mg) or more per day
Interaction between CRO and SponsorInteraction between CRO and Sponsor
In order to launch and complete studies successfully the following steps are recommended:
• Project Initiation• Provide CRO with DMF information and/or Physico/Chemical properties
of the API• Provide limits for each known residual solvent to CRO if Testing Drug
Product (Based on TDI)• Agree on choice of technology to be utilized in support of testing (GC-
FID or GC/MS)• Is prescreening required?• API Qualification or routine Testing?• Method Validation Scope
Interaction between CRO and SponsorInteraction between CRO and Sponsor
• Method TransferCRO required to review validation reportFeasibilityWrite protocolGenerally, selectivity, LOD/LOQ and RepeatabilityCRO will provide Final report for review and approval
• Routine AnalysisAlways start with USP <467> procedure AUpon completion of studies CRO will provide C of A and Raw data if deemed necessary.
Interaction between CRO and SponsorInteraction between CRO and Sponsor
• Screening Method• It is recommended to perform chromatographic profile for API which
residual solvent are not known and/or their respective limits are not known.
• Generally GC/MS equipped with Head Space analyzer is recommended • Due to its greater sensitivity• Greater selectivity
• In addition to chromatographic profile, following studies need to be evaluated:• LOD/LOQ• Repeatability
Interaction between CRO and SponsorInteraction between CRO and Sponsor
• Follow USP Procedure A • If peak response of any peak in Test solution is ≥ to either peak in
Class I and or Class II proceed to procedure B for ID • Follow USP Procedure C for accurate quantitation of known
residual solvents
Interaction between CRO and SponsorInteraction between CRO and Sponsor
Method ValidationUpon completion of screening method, the method needs to be Validated as follow:
SelectivityLinearity from LOQ to 120% of specified limit for each solventLOD/LOQ for standards and Spiked sampleRepeatabilityIntermediate PrecisionAccuracy: 80 to 120% of each solventRobustness
• GC• Head Space
Interaction between CRO and SponsorInteraction between CRO and Sponsor
Qualification of API
Qualify each API by evaluating 3 consecutive lots of API
If multiple vendors of API are available, perform repeatability in triplicate preparation for each vendor
This work is performed only once
Upon completion of API qualification, test future lots by analyzing samples in triplicate preparation
Interaction between CRO and SponsorInteraction between CRO and Sponsor
Routine API TestingPerform Routing Testing as follow:
Chromatographic non-interferenceLOD/LOQSystem Suitability Bracketing StandardsSample (n=3)BlankBracketing Standard
Selection of MethodologiesSelection of Methodologies
• To determine Residual Solvents, many quality-control labs in pharmaceutical manufacturing employ GC-FID for the determination of residual solvents that are included in either USP <467> or ICH guidelines.
• Because some of the solvents co-elute, these labs must use at least two different separation phases. Co-elution is not a problem with mass spectrometric detection, as most co-eluting analytes have unique ions. The mass spectrometer also provides a means to identify unknown or unexpected contaminants.
• With the 5975 inert Mass Selective Detector (MSD), a single analysis provides both selected ion monitoring (SIM) for sensitive quantitation and full-scan spectra for identification of unknowns.
Selection of MethodologiesSelection of Methodologies
• According to published list in ICH Q3C , there are 61 solvents.
• This list would be a challenge for separation on any single GC phase , as critical coelution will be inevitable.
• In ICH guideline, residual solvents are grouped based on their toxicity, both class I and class 2 need to be analyzed by sensitive and specific methodologies. However, class 3could be assayed by non-specific techniques, such as weight loss on drying <731>, due to their low toxicity.
Selection of MethodologiesSelection of Methodologies
• Due to the advance in head space technology-mainly dynamic sampling techniques, and dual column capability faster analysis, better sensitivity and specificity is possible (MACH system allows up to 4 columns).
• Restek group has reported separation of 23 residual solvents in 8 min by utilizing dual column separation on MACH system. MACH is an Agilent GC 6890 equipped with Gerstel Modular Accelerated ColumnHeater (MACH)
Figure 1. Agilent GC/MS equipped with Head Space AnalyzerAgilent Technologies, 6890N Network GC system, MS: Agilent Technologies, 5975 inert XL Mass Selective Detector Data aAnalysis: Software: G1701DA ChemStation,
Figure 2. CTC Autosampler System for Headspace and Liquid Injection.
Past Challenges 1Past Challenges 1USP OVI Method IV for Class II SolventsUSP OVI Method IV for Class II Solvents
Two early eluting extraneous peaks were detected on sample chromatogram.
Upon laboratory investigation it was determined that these two peaks were reproducible and are process Solvents from API.
In API Technical Package there was no information about those two Unknown peaks.
Further investigation is pending .
Past Challenges 1Past Challenges 1USP OVI Method IV for Class II SolventsUSP OVI Method IV for Class II Solvents
Chromatogram 1
Methylene Chloride
1,4-Dioxane
Trichloromethene
Chloroform
Unknown Peaks
Sample
Standard
Past Challenges 2Past Challenges 2USP OVI Method IV for Class II SolventsUSP OVI Method IV for Class II Solvents
One Late eluting extraneous peak was detected on sample chromatogram.
Laboratory Investigation suggested that Unknown peak is present in every sample preparation of API (Same Lot).
In API Technical Package there was no information about this Unknown peak.
Further investigation is pending
Past Challenges 2Past Challenges 2USP OVI Method IV for Class II SolventsUSP OVI Method IV for Class II Solvents
Chromatogram 2
Chloroform
1,4-Dioxane
Trichloromethene
Methylene Chloride
Sample
Standard
Unkown Peak
Past Challenges IIIPast Challenges IIIUSP OVI Method I for Class II SolventsUSP OVI Method I for Class II Solvents
One early eluting extraneous peak was detected on sample chromatogram.
Laboratory Investigation suggested that Unknown peak is present in every sample preparation of API (Same Lot).
In API Technical Package there was no information about this Unknown peak.
No attempt was made for Identification of Unknown peak.
Past Challenges 3Past Challenges 3USP OVI Method IV for Class II SolventsUSP OVI Method IV for Class II Solvents
Chromatogram 3
Methylene Chloride
Chloroform
Trichloroethylene
Chloroform
Methylene Chloride
Chloroform
1,4-Dioxane
Unknown Peak Standard
Sample
Past ChallengesPast Challenges
Lesson Learned
Perform API Screening by Utilizing GC/MS
Ask for DMF
Qualify your API
Published Methodologies in USPPublished Methodologies in USPProcedure A (Profiling) for Procedure A (Profiling) for WaterWater--Soluble ArticleSoluble Article
Class 1 and Class 2 residual Solvents– Chromatographic Conditions:
Column: 0.32mm x 30 m fused-silica column coated with 1.8 μm layer of G43 or 0.53 mm x 30m wide-bore column coated with 3.0 μm layer of G43Carrier: He or N2 with linear velocity of 35 cm/sec and split ratio of 1:5Column temperature: 50 °C – 6 °C /min--165 °C hold for 20 minInjection port: 140 °CDetector Temperature: FID @ 250 °C Method of Injection: Static Head Space
Note: USP Residual Solvent standards are available
Published Methodologies in USPPublished Methodologies in USPProcedure B (Peak ID)Procedure B (Peak ID)
Class 1 and Class 2 Residual Solvents
Chromatographic Conditions:GC-FIDColumn: 0.32mm x 30 m fused-silica column coated with 0.25 μm layer of G16 or 0.53 mm x 30m wide-bore column coated with 0.25 μm layer of G16Carrier: He or N2 with linear velocity of 35 cm/sec and split ratio of 1:5Column temperature: 40 °C –10 °C /min--240 °C Injection port: 140 °CDetector Temperature: 250 °C Method of Injection: Static Head Space
Published Methodologies in USPPublished Methodologies in USPProcedure CProcedure C
Class 1 and Class 2 Residual Solvents for Water-Soluble Article• Follow Procedure A or B for Quantification of each Residual Solvent• Injection Sequence is as follows:
BlankSystem SuitabilityStandard SolutionTest SolutionSpiked Test SolutionStandard Solution
Screening MethodScreening Method• It is recommended to perform chromatographic profile for API which residual
solvents are not known and/or their respective limits are not known• Generally GC/MS equipped with Head Space analyzer is recommended
• Due to its greater sensitivity• Greater selectivity
• In addition to chromatographic profile, following studies need to be evaluated:• LOD/LOQ• Repeatability
• Follow USP Procedure A • If peak response of any peak in Test solution is ≥ to either peak in Class I
and or Class II proceed to procedure B for ID and • Follow USP Procedure C for accurate quantitation of known residual
solvents
Case Study I : Class I Solvents Incubation TimeCase Study I : Class I Solvents Incubation Time
Objective: To assess affect of incubation time on recovery of Class I solvents in water soluble Matrix.
Methodology: Instrument: Agilent GC-FID equipped with Headspace AnalyzerColumn: Phenomenex ZB-624, 30 m x 0.53 mm, 3μmTemperature program: 40°C for 20 min -----50°C/min to 240°CInjection Port Temp.: 140°CHead Space Parameter: 80°C for 30, 45 and 60 minInjection Volume: 1 ml
Case Study I : Class I Solvents Incubation TimeCase Study I : Class I Solvents Incubation TimeGraph 1
0 500 1000 1500 2000 2500 3000 3500
Benzene
TCE
1,2-DCA
60min45min30min
Peak Area
Case Study I : Class I Solvents Incubation TimeCase Study I : Class I Solvents Incubation Time
Conclusion:
Incubation time had minimum effect on each residual solvent recovery.
However, it is highly recommended to consider conducting robustness studies on critical GC and Head Space parameters.
Case Study II : Screening Method For Class II SolventsCase Study II : Screening Method For Class II Solvents
Objective : To evaluate a Screening method for water soluble Class II solvents
Scope of the Work: Selectivity, LOD/LOQ, System Suitability and Repeatability
Case Study II : Screening Method For Class II Solvents, Case Study II : Screening Method For Class II Solvents, ResultsResults
Methylene ChlorideTrichloromethene Toluene
Blue: Spike sampleRed: BlankGreen: Unspike Sample
Case Study III : DMSO Selection for NonCase Study III : DMSO Selection for Non--Aqueous Aqueous Soluble APISoluble API
Objective: To evaluate chromatographic profile of various DMSOScope: Selectivity of method for non –Aqueous soluble API was assessed by utilization of different grades of DMSO as diluent
– Method: GC/FID equipped with Head Space Analyzer– Column: ZB 624, 30 m x 0.53 mm, 3 μm (USP G43)
Case Study III : DMSO Selection for NonCase Study III : DMSO Selection for Non--Aqueous Aqueous Soluble APISoluble API
Results
DMSO A (Blank)
DMSO A with Sample
Case Study III : DMSO Selection for NonCase Study III : DMSO Selection for Non--Aqueous Aqueous Soluble APISoluble API
DMSO B (Blank)
DMSO B with Sample
Case Study III : DMSO Selection for NonCase Study III : DMSO Selection for Non--Aqueous Aqueous Soluble APISoluble API
DMSO C with Sample
DMSO C (Blank)
SummarySummary
Review API DMF or Technical Package Perform Screening of APIQualify API
AcknowledgementAcknowledgement
Ruggero Pocci Ruggero Pocci GC Group LeaderGC Group LeaderDavid PrideDavid Pride GC ScientistGC ScientistHamid ForouharHamid Forouhar QC managerQC managerMai Zhang,PhD Mai Zhang,PhD Sr. ScientistSr. Scientist