Drug discovery and development is a fascinating journey from finding...
Biology315 views·Updated 18 Jul 2026·2 pagesUnderstanding Drug Discovery: INFECTION, RESPONSE, and Clinical Trials
alisa@ayselv
1
of 2
Discovery and Development of Drugs
Ever wondered where medicines come from? Some drugs occur naturally in plants and animals, while others are made in laboratories. Naturally occurring drugs like digitalis (from foxglove plants) help treat irregular heartbeats, while aspirin (originally from willow trees) reduces pain and fever. Penicillin, discovered in mould, revolutionised medicine as an antibiotic.
Creating new medicines is a massive undertaking. Pharmaceutical companies spend up to £1700 million and 12 years developing a single drug! They start with promising compounds (often from plants) and modify them to create effective treatments. A good medicine must be effective at treating the condition, safe to use, stable during storage, and properly absorbed and removed by the body.
Drug development begins with preclinical testing in laboratories on cells, tissues and sometimes entire organs. Scientists check if the drug works (efficacy) and assess its toxicity. UK law requires testing on two different animal species to understand how the drug might behave in humans and identify potential side effects. Next come clinical trials on humans, starting with healthy volunteers receiving very low doses.
Did you know? While animal testing is mandatory for medicines in the UK, it's illegal to test cosmetics and tobacco products on animals. This reflects changing attitudes about animal welfare while recognising the necessity for safety testing.
Clinical trials progress through distinct phases. Phase I involves 20-30 healthy volunteers to determine safe dosages and identify harmful side effects. Scientists carefully monitor how the drug moves through the body and whether it reaches its target area for long enough to work effectively.
2
of 2
Clinical Trials and Approval Process
The testing gets more thorough as development continues. Phase II trials involve 100-300 patients who actually have the condition the drug aims to treat. Scientists now focus on finding the optimal dose, confirming the drug works effectively, and documenting side effects. To prevent bias, researchers often use double-blind placebo controls – where neither patients nor researchers know who's receiving the actual medicine versus a dummy treatment.
The final testing stage, Phase III, is massive – involving 1,000-5,000 volunteers across different countries. These extensive trials monitor long-term use, confirm effective dosing, and identify any contraindications (reasons why certain people shouldn't take the medicine). Researchers compare the new drug's performance against existing treatments to demonstrate its value.
After successful trials, the Medicines and Healthcare products Regulatory Agency (MHRA) reviews all evidence. If approved, they issue a licence allowing the drug to be manufactured and sold. But monitoring doesn't stop there – post-market testing continues to track performance and safety in the wider population. All trial results undergo peer review by medical professionals before publication.
Important: The National Institute for Health and Care Excellence (NICE) evaluates which drugs provide good value for money and should be available on the NHS. This ensures that healthcare resources are used effectively.
Clinical trials use several methods to ensure reliable results. In blind trials, volunteers don't know if they're receiving the actual drug or a placebo. Even better are double-blind trials, where neither doctors nor patients know who's in which group, preventing observer bias from influencing results. For extremely serious conditions with no alternative treatments, open-label trials may be used where everyone knows which treatment is being given.
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Biology315 views·Updated 18 Jul 2026·2 pagesUnderstanding Drug Discovery: INFECTION, RESPONSE, and Clinical Trials
alisa@ayselv
Drug discovery and development is a fascinating journey from finding potential treatments to creating safe, effective medicines. This process involves rigorous testing, careful evaluation, and multiple stages of clinical trials before a drug can be approved for human use. Let's...
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Discovery and Development of Drugs
Ever wondered where medicines come from? Some drugs occur naturally in plants and animals, while others are made in laboratories. Naturally occurring drugs like digitalis (from foxglove plants) help treat irregular heartbeats, while aspirin (originally from willow trees) reduces pain and fever. Penicillin, discovered in mould, revolutionised medicine as an antibiotic.
Creating new medicines is a massive undertaking. Pharmaceutical companies spend up to £1700 million and 12 years developing a single drug! They start with promising compounds (often from plants) and modify them to create effective treatments. A good medicine must be effective at treating the condition, safe to use, stable during storage, and properly absorbed and removed by the body.
Drug development begins with preclinical testing in laboratories on cells, tissues and sometimes entire organs. Scientists check if the drug works (efficacy) and assess its toxicity. UK law requires testing on two different animal species to understand how the drug might behave in humans and identify potential side effects. Next come clinical trials on humans, starting with healthy volunteers receiving very low doses.
Did you know? While animal testing is mandatory for medicines in the UK, it's illegal to test cosmetics and tobacco products on animals. This reflects changing attitudes about animal welfare while recognising the necessity for safety testing.
Clinical trials progress through distinct phases. Phase I involves 20-30 healthy volunteers to determine safe dosages and identify harmful side effects. Scientists carefully monitor how the drug moves through the body and whether it reaches its target area for long enough to work effectively.
2
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Clinical Trials and Approval Process
The testing gets more thorough as development continues. Phase II trials involve 100-300 patients who actually have the condition the drug aims to treat. Scientists now focus on finding the optimal dose, confirming the drug works effectively, and documenting side effects. To prevent bias, researchers often use double-blind placebo controls – where neither patients nor researchers know who's receiving the actual medicine versus a dummy treatment.
The final testing stage, Phase III, is massive – involving 1,000-5,000 volunteers across different countries. These extensive trials monitor long-term use, confirm effective dosing, and identify any contraindications (reasons why certain people shouldn't take the medicine). Researchers compare the new drug's performance against existing treatments to demonstrate its value.
After successful trials, the Medicines and Healthcare products Regulatory Agency (MHRA) reviews all evidence. If approved, they issue a licence allowing the drug to be manufactured and sold. But monitoring doesn't stop there – post-market testing continues to track performance and safety in the wider population. All trial results undergo peer review by medical professionals before publication.
Important: The National Institute for Health and Care Excellence (NICE) evaluates which drugs provide good value for money and should be available on the NHS. This ensures that healthcare resources are used effectively.
Clinical trials use several methods to ensure reliable results. In blind trials, volunteers don't know if they're receiving the actual drug or a placebo. Even better are double-blind trials, where neither doctors nor patients know who's in which group, preventing observer bias from influencing results. For extremely serious conditions with no alternative treatments, open-label trials may be used where everyone knows which treatment is being given.
We thought you’d never ask...
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
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