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Venkata Chaitanya Reddi ☆ India, 2023-06-14 12:19 (536 d 07:24 ago) Posting: # 23590 Views: 2,354 |
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Hi All, Greeting for the Day!!! Regarding Isotretinoin Capsules 40 mg fed studies, for the test product, the reported arithmetic mean Cmax of baseline-corrected isotretinoin is 2326.2448 ng/mL for fed BE study which is failed and 912.1610 ng/mL is reported for repeat fed BE study with same test product, while the bioanalytical method and bioanalytical site for the two BE studies are same. Specifically, the Cmax and AUCs in the failed fed BE study are more than two-fold higher than those reported for the repeat fed BE study. What could be the reason(s) for the observed significant difference in Cmax. Please provide the available literature to support the observed difference on the bioequivalence evaluation. Appreciate your help in advance. Thank you, Venkata Chaitanya Reddi. Edit: Category changed; see also this post #1. [Helmut] — Venkata Chaitanya Reddi |
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dshah ★★ India, 2023-06-15 10:29 (535 d 09:15 ago) @ Venkata Chaitanya Reddi Posting: # 23596 Views: 1,928 |
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Dear Venkata! There can be various reason. We had seen such case when standard batch/lot was changed resulting into 50% difference. Is the serial number of instrument same? If the levels have changed- does your CC range was able to capture the change? Regards, Divyen |
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Venkata Chaitanya Reddi ☆ India, 2023-06-16 06:21 (534 d 13:22 ago) (edited on 2023-06-16 10:54) @ dshah Posting: # 23600 Views: 1,910 |
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❝ We had seen such case when standard batch/lot was changed resulting into 50% difference. Is the serial number of instrument same? ❝ If the levels have changed- does your CC range was able to capture the change? Edit: Please follow the Forum’s Policy when editing/deleting text. [Helmut] — Venkata Chaitanya Reddi |
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dshah ★★ India, 2023-06-16 10:27 (534 d 09:17 ago) @ Venkata Chaitanya Reddi Posting: # 23601 Views: 1,956 |
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Dear Venkata! ❝ We believe that these are the potential causes. ❝ ❝ but, we are using same test product batch no. and reference product batch no was different. I think you are getting it wrong. The reference standard means the API used in CC and QC preparation. The change in reference standard, your reference lot, Instrument change can directly have impact on your S/N ratio and can give you different level. Can you confirm that the S/N and then the area of standards and CC remains similar between the study? This can give you a good idea that there is some change. Further your CC range remains same indicating that the levels were anticipated. As the study sample analysis is performed using same instrument, reference standard (for same study)- it would have minimal impact on outcome i.e. ratio and 90% CI. If you are trying to corelated the failed study and change in concentration level- it may not be fruitful. Regards, Divyen |
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Venkata Chaitanya Reddi ☆ India, 2023-06-16 10:48 (534 d 08:56 ago) @ dshah Posting: # 23602 Views: 1,913 |
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❝ I think you are getting it wrong. […] thanks for correcting me. will provide requested data soon. Regards, Venkata Chaitanya Reddi. Edit: Full quote removed. Please delete everything from the text of the original poster which is not necessary in understanding your answer; see also this post #5! [Helmut] — Venkata Chaitanya Reddi |
Ing. Helmut Schütz