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chiragkhatri ★ India, 2010-01-01 17:51 (6020 d 16:08 ago) Posting: # 4550 Views: 4,039 |
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Dear Members, We are planning to conduct relative bioavailability of effervescent tablets of series of antibiotic drugs.These formulations are first time and hence no reference is available. I would like to know on what basis the blood sampling time points be decided. Thanks Chirag |
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Helmut ★★★   Vienna, Austria, 2010-01-01 18:04 (6020 d 15:54 ago) @ chiragkhatri Posting: # 4551 Views: 3,445 |
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Dear Chirag, the main problem with effervescent formulations is the ‘First Point Cmax’. See for example FDA (2003, ![[image]](img/uploaded/IAsmall.png) Section VI.D.):The first point of a concentration-time curve in a BE study based on blood and/or plasma measurements is sometimes the highest point, which raises a question about the measurement of true Cmax because of insufficient early sampling times. A carefully conducted pilot study may avoid this problem. Collection of an early time point between 5 and 15 minutes after dosing followed by additional sample collections (e.g., two to five) in the first hour after dosing may be sufficient to assess early peak concentrations. If this sampling approach is followed, we recommend that data sets be considered adequate, even when the highest observed concentration occurs at the first time point. or EMA’s BE-Draft (2008, Section 4.1.4.)The sampling schedule should include frequent sampling around Cmax to provide a reliable estimate of peak exposure. The sampling schedule should be planned to avoid Cmax being the first point of a concentration time curve. — 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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chiragkhatri ★ India, 2010-01-02 05:45 (6020 d 04:13 ago) (edited on 2010-01-02 13:56) @ Helmut Posting: # 4552 Views: 3,478 |
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Dear HS, Thank you very much for your reply. I also wish to know whether the reference product which is a suspension can be taken into consideration for Tmax for designing time points of an effervescent tablet. Regards Chirag Edit: Full quote removed. Please delete anything from the text of the original poster which is not necessary in understanding your answer; see also this post! [Ohlbe] |
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Helmut ★★★ Vienna, Austria, 2010-01-02 16:57 (6019 d 17:01 ago) @ chiragkhatri Posting: # 4553 Views: 3,512 |
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Dear Chirag! ❝ I also wish to know whether the reference product which is a suspension can be taken into consideration for Tmax for designing time points of an effervescent tablet. Difficult to answer. A solution must no necessarily show a faster absorption than a suspension. Sometimes excipients in a suspension enhance absorption, whereas the API in solution precipitates in the stomach. I would suggest to perform a small pilot study. — 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