====== Preclinical Animal Study ======

A **preclinical [[animal study]]** is a type of [[scientific research]] conducted prior to initiating [[clinical trial]]s in humans. Its primary aim is to assess the **safety**, **toxicity**, **pharmacokinetics**, and often the **preliminary efficacy** of a proposed medical intervention.

===== 🔍 Purpose =====
  * To determine if a new drug, therapy, or device is **safe** and **potentially effective** before human testing.
  * To support regulatory submissions (e.g., [[FDA]] IND application).

===== 🐁 Animal Models =====
  * Use of animals that **mimic human disease** or relevant physiological conditions.
  * Common species: mice, rats, rabbits, pigs, non-human primates.
  * Models must demonstrate:
    * [[Biological relevance]]
    * [[Predictive validity]] for human outcomes

===== 🔬 Typical Assessments =====
  * **Toxicity studies** (acute, subacute, chronic)
  * **Histopathological evaluation**
  * **Organ function monitoring**
  * **Drug absorption, distribution, metabolism, excretion (ADME)**
  * **Behavioral and neurological testing** (in neuro studies)

===== ⚖️ Ethical Considerations =====
  * Compliance with ethical standards and animal welfare laws
  * Implementation of the [[3Rs]]:
    - **Replacement** (use alternatives when possible)
    - **Reduction** (minimize number of animals)
    - **Refinement** (optimize procedures to reduce suffering)

===== 📋 Regulatory Importance =====
  * Preclinical results are required to:
    * Define starting dose in human trials
    * Justify trial design and risk mitigation
    * Obtain approval for [[first-in-human studies]]

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====== Preclinical vs Experimental Animal Study ======

While closely related, **preclinical animal studies** and **experimental animal studies** are not exactly the same. Below is a structured comparison:

^ Feature                          ^ Preclinical Animal Study                             ^ Experimental Animal Study                             ^
| **Definition**                   | Subset of animal research aimed at clinical translation | Broad category of studies involving animals           |
| **Primary Purpose**              | To evaluate safety, toxicity, pharmacokinetics, and preliminary efficacy before human trials | To explore biological mechanisms, disease models, or test hypotheses |
| **Regulatory Context**           | Required for regulatory submission (e.g., [[FDA]] IND) | Not necessarily linked to regulatory processes        |
| **Goal**                         | Support first-in-human trials                         | Generate scientific knowledge, may or may not be translational |
| **Typical Outputs**              | Data for dose selection, risk assessment, trial design | Mechanistic insights, disease modeling, biomarker discovery |
| **Examples**                     | Testing new drug in mice before human trial           | Studying gene expression changes in Alzheimer’s mice  |
| **Field**                        | Translational / applied research                      | Basic or applied research                             |
| **Scope**                        | Narrower: focused on clinical applicability           | Broader: includes all types of animal experimentation |

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**Summary**:  
  * All **preclinical animal studies** are **experimental**,  
  * But not all **experimental animal studies** are **preclinical**.

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**Tags**: preclinical, experimental, animal studies, translational research, basic science, IND