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Trial by Science

From foxglove to pharmacy: how a new drug is discovered, tested and trialled — preclinical, clinical, placebo and double-blind.

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What you'll cover

Trial by Science 🧪

Before a new medicine reaches a pharmacy it faces years of testing — designed to answer two questions: is it **safe**, and does it **work**? This module follows a drug from its natural source through preclinical testing and human trials to approval.

Where drugs come from 🌿

Many drugs were originally extracted from **plants and microorganisms**: • **Digitalis** — a heart drug from **foxgloves**. • **Aspirin** — a painkiller from **willow** bark. • **Penicillin** — the first antibiotic, discovered by **Alexander Fleming** from the **Penicillium mould**.

Name the source

The antibiotic **penicillin** was originally discovered from what?

  • A mould (Penicillium), by Alexander Fleming
  • The foxglove plant
  • Willow bark
  • An animal

Three questions ⚖️

Every potential new drug is tested for three things: • **Toxicity** — is it **harmful**? • **Efficacy** — does it actually **work**? • **Dose** — **how much** should be given?

Match the terms

  • Toxicity
  • Efficacy
  • Dose
  • Is the drug harmful?
  • Does the drug actually work?
  • How much should be given?

Two stages of testing 🧬

Testing runs in two big stages: • **Preclinical** — in the lab, on **cells, tissues and live animals**. • **Clinical trials** — on **humans**: first **healthy volunteers** at very low doses to check safety, then **patients** to find the best dose. Safety always comes before dose — you never give a large dose until you know it isn't toxic.

Order the testing

An interactive activity.

Removing bias 🎭

To trust the results, trials are designed to remove **bias**: • A **placebo** is a dummy treatment with no active drug. Some patients get it so the drug's effect can be compared fairly. • In a **double-blind** trial, **neither the patients nor the doctors** know who got the real drug — so expectations can't sway the result. • Finally, results are **peer reviewed** — checked by other scientists before publication — to catch false claims.

Who knows?

In a **double-blind** trial, who knows which patients are getting the real drug rather than the placebo?

  • Neither the patients nor the doctors
  • Only the doctors
  • Only the patients
  • Everyone is told

Complete the process

New drugs are first tested in the lab on cells, tissues and _____, then in clinical trials on human _____. To remove bias, trials are often _____.

animals volunteers double-blind harmful

True of clinical trials?

Pick the TWO correct statements about clinical trials.

  • Healthy volunteers are tested first, at low doses, to check safety
  • In a double-blind trial neither doctor nor patient knows who got the real drug
  • New drugs skip lab testing and go straight to patients
  • Patients are always told immediately if they got the placebo

In the exam 🎓

Trial complete. Grade-9 habits for drug development: • Drugs are tested for **toxicity, efficacy and dose** — **safety first**, always. • **Preclinical** = cells, tissues, animals; **clinical** = healthy volunteers then patients. • **Placebo** and **double-blind** remove bias; **peer review** checks the results before they're published.