A dumb answer [Bioanalytics]
Hi John,
Are you talking about a drug with protein binding? That’s easy. Protein binding is caused by Van der Waals force, which is extremely weak. In a nutshell, in any extraction (liquid-liquid, solid-phase), or protein-precipitation the protein-drug bonds will be practically immediately cleaved and therefore, from the extract you get always the total concentration.
If you are interested in the free concentration, you would have to use ultra-filtration or -centrifugation of the same sample, measure this concentration and the total. The protein binding: $$\small{PB(\%)=100\frac{C_\text{total}-C_\text{free}}{C_\text{total}}}$$ Important for new drugs but completely uninteresting in BE.
Liposome encapsulated drugs and their relatives are different beasts.
❝ A dumb question …
❝ Is there a way to find out whether the total drug concentration is measured from a bioanalytical report (no method development report, just bioanalytical and validation reports) if there is no sentence/discussion about that aspect? I read through a report that I was given and I didn't find info on this.
Are you talking about a drug with protein binding? That’s easy. Protein binding is caused by Van der Waals force, which is extremely weak. In a nutshell, in any extraction (liquid-liquid, solid-phase), or protein-precipitation the protein-drug bonds will be practically immediately cleaved and therefore, from the extract you get always the total concentration.
If you are interested in the free concentration, you would have to use ultra-filtration or -centrifugation of the same sample, measure this concentration and the total. The protein binding: $$\small{PB(\%)=100\frac{C_\text{total}-C_\text{free}}{C_\text{total}}}$$ Important for new drugs but completely uninteresting in BE.
Liposome encapsulated drugs and their relatives are different beasts.
—
Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz
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Dif-tor heh smusma 🖖🏼 Довге життя Україна!
Helmut Schütz
The quality of responses received is directly proportional to the quality of the question asked. 🚮
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Complete thread:
- A dumb question jag009 2024-08-12 13:17 [Bioanalytics]
- A dumb answerHelmut 2024-08-12 13:45
- A dumb answer jag009 2024-08-12 14:35
- A dumb answer Helmut 2024-08-12 15:01
- A dumb answer ElMaestro 2024-08-12 15:13
- A dumb answer Helmut 2024-08-12 15:30
- A dumb answer ElMaestro 2024-08-12 15:13
- A dumb answer Helmut 2024-08-12 15:01
- A dumb answer jag009 2024-08-12 14:35
- An alternate dumb answer Ohlbe 2024-08-12 21:37
- An alternate dumb answer jag009 2024-08-13 06:27
- Unconjugated ≠ free Helmut 2024-08-13 07:31
- Unconjugated ≠ free jag009 2024-08-26 16:19
- A dumb question Achievwin 2024-08-27 03:02
- A dumb answerHelmut 2024-08-12 13:45