Peer Review Panel Report:
The Use of In Vitro Basal Cytotoxicity
Test Methods for Estimating Starting Doses for Acute Oral Systemic Toxicity Testing Report Table of Contents
Introduction and Rationale for the Use of In Vitro Neutral Red Uptake Cytotoxicity Test Methods to Predict Starting Doses for In Vivo Acute Oral Systemic Toxicity Testing
Background and Rationale for the Use of In Vitro Cytotoxicity Test Methods to Predict Starting Doses for In Vivo Acute Oral Systemic Toxicity Tests
Regulatory Rationale and Applicability for the Use of In Vitro Cytotoxicity Test Methods to Predict Starting Doses for Acute Oral Systemic Toxicity Testing
Scientific Basis for the In Vitro NRU Test Methods
Test Method Protocol Components of the 3T3 and NHK In Vitro NRU Test
Methods
Overview of the 3T3 and NHK NRU Test Methods
Descriptions and Rationales of the 3T3 and NHK NRU Test
Methods
Basis for Selection of the In Vitro NRU Cytotoxicity Test Methods
Proprietary Components of the 3T3 and NHK NRU Test Method
Protocols
Basis for Number of Replicate and Repeat Experiments for the 3T3
and NHK NRU Test Methods
Basis for Modifications to the 3T3 and NHK NRU Test Method Protocols
Differences in 3T3 and NHK NRU Test Method Protocols and the Guidance Document Standard Protocols
Overview of the Solubility Protocol
Components of the Solubility Protocol
Basis of the Solubility Protocol
Summary
Reference Substances Used for Validation of the 3T3 and NHK NRU Test Methods
Rationale for the Reference Substances Selected for Testing
Rationale for the Number of Reference Substances Selected
Characteristics of the Selected Reference Substances
Reference Substance Procurement, Coding, and Distribution
Reference Substances Recommended by the Guidance Document (ICCVAM 2001b)
Summary
In Vivo Rodent Toxicity Reference Values Used to Assess the Accuracy of the 3T3 and NHK NRU Test Methods
Methods Used to Determine In Vivo Rodent Toxicity Reference Values
Final In Vivo Rodent Toxicity Reference Values
Relevant Toxicity Information for Humans
Accuracy and Reliability of the In Vivo Rodent Toxicity Reference
Values
Summary
3T3 and NHK NRU Test Method Data and Results
3T3 and NHK NRU Test Method Protocols
Data Obtained to Evaluate Accuracy and Reliability
Statistical Approaches to the Evaluation of 3T3 and NHK NRU Data
Summary of Results
Coded Reference Substances and GLP Guidelines
Study Timeline and NICEATM/ECVAM Study Participatory
Laboratories
Availability of Data
Solubility Test Results
Summary
Accuracy of the 3T3 and NHK NRU Test Methods
Accuracy of the 3T3 and NHK NRU Test Methods for Predicting Acute Oral Systemic Toxicity
Improving the Prediction of Rodent LD50 Values from In Vitro NRU IC50 Data
Accuracy of the 3T3 and NHK NRU Test Methods for Toxicity
Category Predictions
Strengths and Limitations of the 3T3 and NHK NRU Test Methods
for In Vivo Toxicity Prediction
Salient Issues of Data Interpretation
Comparison to Established Performance Standards
Summary
Reliability of the 3T3 and NHK NRU Test Methods
Substances Used to Determine the Reliability of the 3T3 and NHK
NRU Test Methods
Reproducibility Analyses for the 3T3 and NHK NRU Test Methods
Historical Positive Control Data
Laboratory Concordance for Solvent Selection
Summary
3T3 and NHK NRU Test Method Data Quality
Adherence to Good Laboratory Practice Guidelines
Results of Data Quality Audits
Impact of Deviations from GLPs/Non-compliance
Availability of Laboratory Notebooks
Summary
Other Scientific Reports and Reviews of In Vitro Cytotoxicity Test Methods
and the Ability of These Test Methods to Predict Acute Systemic Toxicity
Relevant Studies
Independent Scientific Reviews
Studies Using In Vitro Cytotoxicity Test Methods with Established Performance Standards
Summary
Animal Welfare Considerations (Refinement, Reduction, and Replacement)
Use of 3T3 and NHK NRU Test Methods to Predict Starting Doses for Acute Systemic Toxicity Assays
Reduction and Refinement of Animal Use for the UDP
Reduction and Refinement of Animal Use for the ATC
Summary
Practical Considerations
Transferability of the 3T3 and NHK NRU Test Methods
3T3 and NHK NRU Test Method Training Considerations
Test Method Cost Considerations
Time Considerations for the 3T3 and NHK NRU Test Methods
Summary
VALIDATION STATUS OF THE NRU TEST METHODS
DRAFT ICCVAM RECOMMENDATIONS FOR IN VITRO ACUTE TOXICITY TEST METHODS
APPENDIX A: DRAFT PERFORMANCE STANDARDS FOR IN VITRO
ACUTE TOXICITY METHODS
APPENDIX B: DRAFT RECOMMENDED TEST METHOD PROTOCOLS