and collect data during the study.

Quality Assurance (QA): Ensure compliance with internal SOPs, GLP standards, and regulatory guidelines, and verify the accuracy and integrity of the data.

4) Procedure

The following steps outline the procedure for establishing dose-response curves in preclinical studies:

1. Step 1: Study Design
   1. Define the study objectives, including the desired endpoints (e.g., therapeutic efficacy, toxicity, pharmacokinetics).
   2. Select the appropriate animal model based on the pharmacological target and disease being studied. The model should be relevant to human conditions to ensure translational relevance.
   3. Determine the doses to be tested. Include a range of doses, including a vehicle control, lower and higher doses, and doses that are expected to produce sub-therapeutic, therapeutic, and toxic effects.
   4. Establish the dosing schedule, including the route of administration (e.g., oral, intravenous) and frequency of dosing (e.g., daily, once a week). Ensure that the protocol accounts for adequate washout periods, if necessary.
   5. Define the treatment and control groups, ensuring that all groups are randomly assigned and that adequate sample sizes are included to achieve statistical power.
2. Step 2: Preparation and Administration of Test Substance
   1. Prepare the test substance (drug candidate) in the appropriate formulation for the chosen route of administration. Ensure that the dose is accurately calculated based on animal weight and the study design.
   2. Administer the test substance to the animals according to the protocol, ensuring that all animals receive the correct dose at the prescribed frequency.
   3. Monitor animals for any immediate signs of toxicity or adverse effects following administration, and record observations as necessary.
3. Step 3: Monitoring and Data Collection
   1. Monitor the animals closely for any behavioral, physiological, or clinical signs following administration, such as changes in body weight, food/water consumption, and signs of distress or toxicity.
   2. Conduct any relevant assays (e.g., biochemical, histological, or pharmacological) at predetermined time points to assess the biological effects of the drug at each dose.
   3. Record the data for each group, including the dose administered, observed effects, and any adverse events or toxicity observed during the study.
4. Step 4: Data Analysis and Dose-Response Curve Generation
   1. Analyze the data to determine the relationship between the administered dose and the observed effect. This includes evaluating the dose at which the drug shows maximal effect (Emax) and the dose at which half of the maximal effect is observed (EC50).
   2. Plot the data to generate a dose-response curve, typically using a sigmoidal model or other appropriate mathematical models to fit the data.
   3. Analyze the curve to determine key pharmacological parameters, including the therapeutic window, effective dose range, and potential toxicities at higher doses.
   4. Use appropriate statistical methods (e.g., nonlinear regression) to analyze the data and determine significant differences between doses.
5. Step 5: Reporting and Documentation
   1. Prepare a comprehensive report summarizing the study objectives, methodology, results, and conclusions based on the dose-response data.
   2. Include relevant tables, graphs, and statistical analyses that illustrate the dose-response relationships and any significant findings regarding efficacy and toxicity.
   3. Document any deviations from the study protocol, including reasons for changes and unexpected findings during the study.
   4. Ensure that all raw data, analysis logs, and final reports are securely stored for future reference and regulatory audits.
6. Step 6: Sample Disposal
   1. Dispose of all biological samples, used test substances, and laboratory waste in accordance with biosafety and waste disposal regulations.
   2. Ensure proper disposal of hazardous materials in designated biohazard containers to prevent contamination and ensure safety compliance.

5) Documents

The following documents should be maintained during the dose-response study process:

1. Study Protocols
2. Animal Exposure and Treatment Logs
3. Raw Data and Behavioral Observations
4. Statistical Analysis Logs
5. Dose-Response Study Reports
6. Waste Disposal Records

6) Abbreviations

• GLP: Good Laboratory Practices
• EC50: Effective Concentration for 50% Maximal Effect
• Emax: Maximum Effect
• QA: Quality Assurance
• FDA: Food and Drug Administration

7) References

References to regulatory guidelines and scientific literature that support this SOP:

• OECD Principles of Good Laboratory Practice (GLP)
• FDA Guidelines for Dose-Response Studies
• ICH Guidelines for Nonclinical Safety Testing

8) Version

Version 1.0: Initial version of the SOP.

9) Annexure

Dose-Response Curve Report Template

Dose (mg/kg)	Observed Effect	Statistical Significance (p-value)	Comments/Notes