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RegisterQuantification of S-amlodipine [PK / PD]
posted by Helmut 
– Vienna, Austria, 2016-06-08 03:32 (2871 d 23:26 ago) – Posting: # 16412
Views: 7,336
Hi Mauricio,
I incorrectly assumed that you have a chiral method. Sorry.
There are none. In our case the enantiomeric ratio of the 'racemate' was in fact not 1:1 (checked by MS-MS response and circulardichroism after heart-cut of the eluted peaks). Do you have the study samples already in the fridge without a validated method method? If yes (bad) I would immediately order the certified l-enantiomer. Validate the method with the racemate but state in the protocol that you will correct all concentrations once you have the l-enantiomer. Analyze the study samples with the racemate standards / QCs. This is a last resort - better than to wait for the enantiomer standard and risk that the samples degrade in the meantime. Avoid it in the future.
I incorrectly assumed that you have a chiral method. Sorry.
❝ What are the guaranties of my correct quantification of S-Amlodipine in plasma with a method that do not make any difference between R and S enantiomeres present in analitical reference standard?
There are none. In our case the enantiomeric ratio of the 'racemate' was in fact not 1:1 (checked by MS-MS response and circulardichroism after heart-cut of the eluted peaks). Do you have the study samples already in the fridge without a validated method method? If yes (bad) I would immediately order the certified l-enantiomer. Validate the method with the racemate but state in the protocol that you will correct all concentrations once you have the l-enantiomer. Analyze the study samples with the racemate standards / QCs. This is a last resort - better than to wait for the enantiomer standard and risk that the samples degrade in the meantime. Avoid it in the future.
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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. 🚮
Science Quotes
Complete thread:
- Linear Pharmacokinetics of Levamlodipine Mauricio Sampaio 2015-10-07 00:24
![[Mix]](https://static.bebac.at/img/mix.png "open in Mix view")
- Linear Pharmacokinetics of Levamlodipine Mauricio Sampaio 2016-06-03 22:33
- Quantification of S-amlodipine Mauricio Sampaio 2016-06-06 16:19
- Quantification of S-amlodipine Helmut 2016-06-06 20:23
- Quantification of S-amlodipine nobody 2016-06-07 08:29
- Quantification of S-amlodipine Mauricio Sampaio 2016-06-07 18:35
- Quantification of S-amlodipineHelmut 2016-06-08 01:32
- Quantification of S-amlodipine Mauricio Sampaio 2016-06-09 21:48
- Quantification of S-amlodipineHelmut 2016-06-08 01:32
- Quantification of S-amlodipine Mauricio Sampaio 2016-06-07 18:35
- Quantification of S-amlodipine nobody 2016-06-07 08:29
- Quantification of S-amlodipine Helmut 2016-06-06 20:23
- Quantification of S-amlodipine Mauricio Sampaio 2016-06-06 16:19
- Linear Pharmacokinetics of Levamlodipine martin 2016-06-09 15:22
- Linear Pharmacokinetics of Levamlodipine Mauricio Sampaio 2016-06-09 22:03
- Linear Pharmacokinetics of Levamlodipine martin 2016-06-12 21:48
- Linear Pharmacokinetics of Levamlodipine Mauricio Sampaio 2016-06-09 22:03
- Linear Pharmacokinetics of Levamlodipine Mauricio Sampaio 2016-06-03 22:33
Ing. Helmut Schütz