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BEAZ ★ India, 2008-03-25 10:49 (6671 d 08:13 ago) Posting: # 1716 Views: 6,042 |
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dear all can any one suggest the blood sampling points for bicalutamide as the Tmax is around 31.3h (from US RLD label) thanks and regards — Alhas |
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Helmut ★★★   Vienna, Austria, 2008-03-26 17:32 (6670 d 01:30 ago) @ BEAZ Posting: # 1725 Views: 5,156 |
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Dear Alhas! ❝ can any one suggest the blood sampling points for bicalutamide as the Tmax is around 31.3h (from US RLD label) OK, you are talking about the active isomer R(-)bicalutamide. Some points to consider: You must be able to show descriptively data of the inactive S(+) isomer as well. This complicates things, because the tmax of S(+) is about 4 hours only (and t½ about 22 hours). Therefore your sampling time points must be able to describe both profiles… Due to the long half life of R(-) I would go with a parallel study; truncated AUC should do the job pretty well. In one study in 58 subjects we saw a tmax of R(-) in two subjects at 72 hours – to be on the safe side, I would sample until 96 hours. — 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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BEAZ ★ India, 2008-03-31 16:36 (6665 d 03:25 ago) @ Helmut Posting: # 1730 Views: 4,998 |
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Dear Helmut Thanks for the input, only R(-)bicalutamide is found to be active why we have to quantify the inactive S(+)metabolite also, as per the FDA's recommendation analyte to be measured is "bicalutamide". Thanks and Regards — Alhas |
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Helmut ★★★ Vienna, Austria, 2008-03-31 17:03 (6665 d 02:58 ago) @ BEAZ Posting: # 1732 Views: 5,030 |
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Dear Alhas! ❝ […] only R(-)bicalutamide is found to be active why we have to quantify the inactive S(+)metabolite also, as per the FDA's recommendation analyte to be measured is "bicalutamide". If you are referring to FDA's draft and are going for a submission at the FDA, you will have to submit/discuss the protocol anyway...  I was talking from a European perspective (NfG on BA/BE, Section 3.4, last paragraph). According to the requirements of the note for guidance on the "Investigation of Chiral Active Substances", bioequivalence studies supporting applications for essentially similar medicinal products containing chiral active substances should be based upon enantiomeric bio-analytical methods unless (1) both products contain the same stable single enantiomer; (2) both products contain the racemate and both enantiomers show linear pharmacokinetics. If you have data supporting (2), fine; we hadn't. The same approach is suggested by the WHO (Section 6.6.6) and many other countries as well. Please check the Guidance page for further informations. — 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