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Mauricio Sampaio ★ Brazil, 2013-05-12 23:59 (4380 d 21:27 ago) Posting: # 10576 Views: 8,456 |
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Anybody have information about linear or nonlinear pharmacokinetics of lymecycline? Are there dose-proportionality between 300 mg and 150 mg strength? Thank you in advance for any reference sent. |
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Dr_Dan ★★ Germany, 2013-05-13 11:39 (4380 d 09:48 ago) @ Mauricio Sampaio Posting: # 10577 Views: 7,269 |
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Hi Mauricio After oral dosing lymecyclin is absorbed readily with or without the presence of food. Lymecycline is more readily absorbed from the gastro-intestinal tract than tetracycline, with a peak serum concentration of approximately 2mg/L after 3 hours following a 300 mg dose. In addition, similar blood concentrations are achieved with small doses. When the dose is doubled an almost correspondingly higher blood concentration has been reported to occur. (SmPC Lymecycline 408mg Capsules, hard and SmPC Tetralysal 30') Kind regards Dan — Kind regards and have a nice day Dr_Dan |
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Mauricio Sampaio ★ Brazil, 2013-05-14 03:12 (4379 d 18:14 ago) @ Dr_Dan Posting: # 10580 Views: 7,181 |
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Hi Dan. Thank you, but I keep my doubt. Are there or not linear pharmacokinetics between 150 mg and 300 mg? The text above not allow to concluded about it. |
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Dr_Dan ★★ Germany, 2013-05-14 11:32 (4379 d 09:54 ago) @ Mauricio Sampaio Posting: # 10581 Views: 7,156 |
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Hi Mauricio you are right, the text of the SmPC is not clear. However, why do you want to know if the PK is linear when only the 300 mg originator is available? A 150 mg formulation would not be a generic and since a comparator is missing you could only test 2×150 test against 1×300 reference and then your question regarding linear PK does not apply, right? For a 150 mg formulation you would also not only need PK data but also data for safety and efficacy. Kind regards Dan — Kind regards and have a nice day Dr_Dan |
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Mauricio Sampaio ★ Brazil, 2013-09-04 02:04 (4266 d 19:22 ago) @ Dr_Dan Posting: # 11422 Views: 6,673 |
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Hi Dan... According your last reply to another question about analyte mensured to lymecycline BE study, I think that PK is linear between 150 mg and 300 mg of Lymecycline. Once tetracycline has linear Pk. |
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Dr_Dan ★★ Germany, 2013-09-04 12:03 (4266 d 09:24 ago) @ Mauricio Sampaio Posting: # 11428 Views: 6,651 |
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Hi Mauricio Lymecycline can not have linear Pk since it is not available in the systemic circulation. The active component of this prodrug tetracycline has linear Pk. However, I still do not know why you want to test your 150 mg formulation against the 300 mg formulation of the originator. A 150 mg formulation would not be a generic and since a respective originator strength is missing you could only test 2×150 test against 1×300 reference. For a new 150 mg formulation you would also not only need PK data but also data for safety and efficacy. Kind regards Dan — Kind regards and have a nice day Dr_Dan |
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Mauricio Sampaio ★ Brazil, 2013-09-07 03:18 (4263 d 18:09 ago) @ Dr_Dan Posting: # 11454 Views: 6,716 |
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Hi Dan I did not expressed myself as I wanted in my last post. What I meant is that I have a possibility to biowaiver of 150 mg strength based on the data of 300 mg lymecycline, because they will come from tetracycline (that has linear PK). In Brazil Tetralysal is marketed in the two forces. Therefore, the bioequivalence study of 300 mg can support a bioiwaiver to smallest strength of 150 mg since the test formulations are proportionate and in vitro profiles of lymecycline are similar. Did you understand me now?  |
Ing. Helmut Schütz