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jag009 ★★★ NJ, 2013-02-05 18:15 (4885 d 12:16 ago) (edited on 2013-02-05 21:46) Posting: # 9966 Views: 3,867 |
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Hi all, When FDA issues a draft guidance stating that "BE will be based on parent compound and metabolite will be measured and presented for information purposes only", does that mean we don't need to set the washout period to accommodate the metabolite in cases where the metabolite half-life is much longer such that potential pre-dose/carryover concentration can occur? Example: Half-life for parent is 6 hours and for metabolite is 20 hours. Use of 7 day washout can lead to pre-dose/carryover concentration for the metabolite. Thanks John |
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drgunasakaran1 ★★  2013-02-06 08:00 (4884 d 22:31 ago) @ jag009 Posting: # 9970 Views: 3,338 |
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Dear Mr John, ❝ does that mean we don't need to set the washout period to accommodate the metabolite No. FDA Guidance for Industry, Bioavailability and Bioequivalence Studies for Orally Administered Drug Products — General Considerations states that "An adequate washout period (e.g., more than 5 half lives of the moieties to be measured) would separate each treatment. Since, the metabolite is also one of the moiety you plan to measure, washout period should be calculated based to half lives of both metabolite and parent compound. ❝ Example: Half-life for parent is 6 hours and for metabolite is 20 hours. Use of 7 day washout can lead to pre-dose/carryover concentration for the metabolite. In my personal opinion, a wash out period of 7 days will be sufficient since FDA recommends more than 5 half lives as wash out period (5*20=100 >4.17 days) — Dr Gunasakaran Sambandan MD Disclaimer: The replies/posts are my personal opinions, and they do not represent my company's views on the same. LinkedIn |
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jag009 ★★★ NJ, 2013-02-06 16:29 (4884 d 14:02 ago) @ drgunasakaran1 Posting: # 9981 Views: 3,109 |
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Thanks drgunasakaran1 |
Ing. Helmut Schütz