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alisa
09/12/2025
Biology
INFECTION AND RESPONSE: Discovery and development of drugs + clinical trials
255
•
9 Dec 2025
•
Understanding Drug Discovery: INFECTION, RESPONSE, and Clinical Trials
alisa
@ayselv
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.
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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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
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This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
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Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
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Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Understanding 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... Show more
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.
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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...
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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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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
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Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
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David K
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Greenlight Bonnie
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I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
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This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
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