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manish_ranbaxy ☆ 2009-03-24 18:26 (6307 d 12:44 ago) Posting: # 3400 Views: 4,580 |
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DEAR ALL, WHAT HAPPENS WHEN BIOSAMPLE IS CENTRIFUGED FOR 5 MINUTES FOR 2500 RCF WHEN IN PROTOCOL IT WAS MENTIONED AS 2500 RCF FOR 10 MINUTES, WILL THE ACTIVE MOEITY WILL BE OF SAME CONCENTRATION IRRESPECTIVE OF CENTRIFUGATION DURATION TIME. |
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babun14 ☆ 2009-03-26 11:26 (6305 d 19:44 ago) (edited on 2009-03-26 11:54) @ manish_ranbaxy Posting: # 3404 Views: 3,664 |
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Dear Manish, Changing of any method validation parameter needs additional proof to support the change. So if the timing of centrifugation has changed then at least one PA batch needs to be done. Thanks Bani -- Edit: Full quote removed. Please see this post. [Jaime] |
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manish_ranbaxy ☆ 2009-03-29 15:29 (6302 d 16:41 ago) @ manish_ranbaxy Posting: # 3410 Views: 3,660 |
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DEAR babun14, THANKS FOR UR REPLY, MY VIEW IS THAT IF IT HAPPENS DURING THE STUDY FOR EXAMPLE I MEAN AT 24.0 HOUR SAMPLE POINT AFTER COLLECTING THE SAMPLE IF IT IS CENTRIFUGED FOR FIVE MINUTES ONLY WHEN IT IS MENTIONED 10 MINUTES IN PROTOCOL CAN WE GET REQUIRED ACTIVE METABOLITES IN PLASMA. REGARDS, MANISH -- Edit: Your keyboard's Shift-key got jammed! You should repair/replace it (I don't assume you're SH  UTING, since you agreed with the forum's policy). Helmut |
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dixit ★ India, 2009-03-30 08:30 (6301 d 23:40 ago) @ manish_ranbaxy Posting: # 3411 Views: 3,595 |
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Dear Manish Goog morning After centrifugation, the blood separates into an upper plasma fraction, comprising ~60% of the sample volume, a lower red blood cell fraction comprising ~40%, and a thin interface layer, called the "buffy coat". Mostly this is done at RPM 3000 for 10-15 min. And if the samples are centrifuged for time less than the specified time, the ratio of plasma and the cells will differ and chances of getting much fraction of plasma gets reduced. In a BA/BE study it will surely effect the plasma volume, as our interest would the amount of drug present in plasma. And to know more it would be better for you to document it as protocol deviation, so that further investigation can be made. Regards DIXIT  |
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manish_ranbaxy ☆ 2009-03-30 12:55 (6301 d 19:15 ago) @ dixit Posting: # 3412 Views: 3,622 |
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DEAR DIXIT, THANK YOU FOR UR REPLY. REGARDS MANI -- Edit: Your keyboard's Shift-key got jammed! You should repair/replace it (I don't assume you're SH UTING, since you agreed with the forum's policy). Helmut |
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Helmut ★★★   Vienna, Austria, 2009-03-30 15:20 (6301 d 16:50 ago) @ dixit Posting: # 3416 Views: 3,635 |
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Dear Dixit! ❝ [...] centrifugation [...] is done at RPM 3000 for 10-15 min. RPM doesn't contain any valuable information unless the diameter of the rotor is given. RCF (relative centrifugal force) should be used instead. ❝ [...] chances of getting much fraction of plasma gets reduced. True. ❝ [...] our interest would the amount of drug present in plasma. False. We are interested in the concentration of drug present in plasma! A potential lower plasma volume may present the analyst with technical problems (e.g., if large volumes are needed and duplicate measurements were planned...) - but the concentration of analyte(s) should be unaffected. ❝ And to know more it would be better for you to document it as protocol ❝ deviation, so that further investigation can be made. That's always nice.  — Dif-tor heh smusma 🖖🏼 Довге життя Україна! ![[image]](https://static.bebac.at/pics/Blue_and_yellow_ribbon_UA.png) Helmut Schütz ![[image]](https://static.bebac.at/img/CC by.png) The quality of responses received is directly proportional to the quality of the question asked. 🚮 Science Quotes |
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dixit ★ India, 2009-03-31 14:28 (6300 d 17:42 ago) @ Helmut Posting: # 3424 Views: 3,526 |
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Dear HELMUT, Yes of course the concentration is not changed. Thank You and Regards, DIXIT |
Ing. Helmut Schütz