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keshav khude ☆ 2010-08-14 10:40 (5778 d 12:06 ago) Posting: # 5786 Views: 4,749 |
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Dear All, During the BE studies, plasma study samples are to transferred from clinical unit to bioanalytical laboratory for analysis under dry ice condition with maintaining required temperature. For this support we are doing one more FT cycle in method validation, but it was not fulfill the requirement to observe any physical impact of dry ice to drug in plasma during transfer with dry ice condition. So for this support, if required Dry Ice Effect experiment during method validation, please answer... Regards, Keshav D. Khude |
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Ohlbe ★★★ France, 2010-08-14 15:16 (5778 d 07:29 ago) @ keshav khude Posting: # 5787 Views: 4,050 |
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Dear Keshav, For small molecules this is currently not required by any guideline. It is generally considered that if you have demonstrated stability at -20°C, it will cover lower temperatures too. There have been some discussions about the possible effect of CO2 on the pH of the samples and from there on stability, but as far as I know no regulatory agency asks for stability on dry ice. For large molecules (proteins) there is much more debate due to the possible influence of variations in temperature on the structure of the proteins. Regards Ohlbe — Regards Ohlbe |
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Helmut ★★★   Vienna, Austria, 2010-08-14 15:24 (5778 d 07:22 ago) @ Ohlbe Posting: # 5789 Views: 4,038 |
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Dear Ohlbe! ❝ There have been some discussions about the possible effect of CO2 on the pH of the samples… Interesting. Even if CO2 diffuses through vial's stoppers, I would guess it would take a remarkably long time to diffuse into the sample (we are talking about penetrating a solid here). BTW, especially plasma's HCO3+ buffer system is a quite strong one.  — 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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Helmut ★★★ Vienna, Austria, 2010-08-14 15:20 (5778 d 07:25 ago) @ keshav khude Posting: # 5788 Views: 3,983 |
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Dear Keshav! ❝ […] plasma study samples are to transferred […] under dry ice condition with maintaining required temperature. For this support we are doing one more FT cycle in method validation, Why? I assume you transfer already frozen samples to the transport boxes / dry ice. No FT should happen here. ❝ […] but it was not fulfill the requirement to observe any physical impact of dry ice to drug in plasma during transfer with dry ice condition. Can you please specify what exactly you have done? One additional FT cycle, or…? ❝ So for this support, if required Dry Ice Effect experiment during method validation, please answer… At the Arlington III conference some participants claimed that for some drugs proven stability at -78 ℃ does not grant stability at -20 ℃; but this is extremely counterintuitive. — 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 |
Ing. Helmut Schütz