Final answer:
Safety tests are essential before entering pre-clinical trials to ensure the drug's safety, identify side effects, and establish the appropriate dosage. Safety tests are conducted through experiments and studies, typically using animals, to evaluate the drug's toxicity and potential risks.
Step-by-step explanation:
Safety testing is essential before entering pre-clinical trials for several reasons. It helps determine whether the drug is safe for human use, identify possible side effects, and establish the appropriate dosage. Safety testing is conducted in pre-clinical trials through a series of experiments and studies, usually using animals, to evaluate the drug's toxicity and potential risks. A drug is considered safe for pre-clinical trials when it has undergone rigorous safety testing and has shown no significant harmful effects.