MGR ★ India, 2007-02-02 11:10 (6579 d 03:26 ago) Posting: # 502 Views: 44,595 |
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Dear all, Please tell me about how to proceed for IVIVC using the pilot data. Also can anybody tell me the important tests and procedure for IVIVC Studies using WinNonlin or any software (SAS, SPSS,.....). If there are any important sites regarding IVIVC kindly let me know. Thanks and regards, MGR — Regards, MGR |
Helmut ★★★ ![]() ![]() Vienna, Austria, 2007-02-07 20:56 (6573 d 17:41 ago) @ MGR Posting: # 510 Views: 43,526 |
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Dear Mamidi! ❝ Please tell me about how to proceed for IVIVC using the pilot data. OK, you are going in the right direction, namely starting with in vivo data! ❝ Also can anybody tell me the important tests and procedure for IVIVC Studies using WinNonlin or any software (SAS, SPSS,.....). Unless you want to start with parametric deconvolution, even M$-Excel will do the job (I would not trust the built-in Solver-routine)… Kinetica offers templates for the ‘classical’ methods (Wagner-Nelson, Loo-Riegelman) and convolution/deconvolution. If you have already a little experience with WinNonlin’s programming language, it should not be too difficult to implement any needed model manually. An additional product (the IVIVC Tookit) is available for the latest release (5.2) of WinNonlin only. ❝ If there are any important sites regarding IVIVC kindly let me know. Not directly IVIVC, but browse through the archive at Dissolution Technologies, and have a look at this nice review. — 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 |
venu ☆ Mumbai, India, 2007-02-23 07:58 (6558 d 06:39 ago) @ Helmut Posting: # 533 Views: 41,308 |
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Dear HS! I would like to share this piece of infomation which I am sure will be useful: http://www.dissolutiontech.com/DTresour/800Articles/800_art1.html Best Regards, Vandana Panchal — Best Regards, Ms. Vandana Panchal Biostatistician Mumbai India |
Dipesh Jayswal ● 2007-03-16 08:53 (6537 d 05:43 ago) @ venu Posting: # 582 Views: 40,958 |
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Dear groupmates, can u please suggest the method for calculating "dose absorbed" at each sampling time point from Plasma concentration Vs Time profile of the subject from Bioequivalence study? Please suggest me the complete procedure with formula or some easily accessible reference on net. Thanks in advance, Dipesh Jayswal |
Helmut ★★★ ![]() ![]() Vienna, Austria, 2007-03-16 16:39 (6536 d 21:57 ago) @ Dipesh Jayswal Posting: # 583 Views: 43,304 |
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Dear Dipesh! First of all get the two ‘classical’ papers; for the 1-compartment model,[1] and for the 2-compartment model.[2] ❝ Please suggest me the complete procedure with formula… Below is a simple example of the Wagner-Nelson method.
┌────┬──────┬───────┬───────┬───────┬──────┐ ❝ … or some easily accessible reference on net. A nice website is run by David Bourne. If you want to examine your own data you will need the Java-plugin for your browser; for examples on absorption see this one of David's pages and followings.
— 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 |
Dipesh Jayswal ● 2007-03-19 11:04 (6534 d 03:32 ago) @ Helmut Posting: # 586 Views: 41,721 |
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Dear HS, Thanks a lot for ur detailed calculation. ![]() Regards, Dipesh |
drcampos ★ Brazil, 2007-03-19 16:26 (6533 d 22:10 ago) @ Helmut Posting: # 587 Views: 41,051 |
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Dr. Helmut, I have just seen your explanation about Wagner-Nelson and Loo-Riegelman methods (model dependent approach). So, if possible, I would like to know how apply deconvolution approach to obtain fraction absorbed using excel. This method is known as model-independent approach. Could you help me with details about calculations and articles about this topic? best regards, Daniel Rossi de Campos Brazil |
Helmut ★★★ ![]() ![]() Vienna, Austria, 2007-03-19 17:20 (6533 d 21:17 ago) @ drcampos Posting: # 588 Views: 45,348 |
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Dear Daniel! ❝ So, if possible, I would like to know how apply deconvolution approach to obtain fraction absorbed using excel. This method is known as model-independent approach. Could you help me with details about calculations and articles about this topic? First I would recommend two other ‘classical’ papers:
![]() Langenbucher F. In vitro Prüfung und Korrelation mit in vivo Daten. In: Meier J, Rettig H, Hess H. Biopharmazie – Theorie und Praxis der Pharmakokinetik. Stuttgart 1981; Georg Thieme: pp 300–3. Main problems with numerical deconvolution are: Sampling points of the response function (e.g., an oral formulation), and the weighting function (i.e., an i.v. dose or an oral solution) must be equidistant, which they almost never are. Therefore you must interpolate ‘missing’ data points by a suitable algorithm (first approximation would be linear interpolation until Tmax, and linear/log afterwards, better options are splines or Lagrange-polynoms). Numerical deconvolution is subject to instability such as sudden oscillations in the input function. Errors in early time points have a cumulative effect upon subsequent estimates. You may use my speadsheet as some kind of a sandbox: alter values, and watch… ![]() But please don’t use it for your actual problems! For the application of M$-Excel in IVIVC have a look at Langenbucher F. Handling of computational in vitro/in vivo correlation problems by Microsoft Excel: III. Convolution and deconvolution. Eur J Pharm Biopharm. 2003; 56(3): 429–37. doi:10.1016/s0939-6411(03)00140-1. Software packages having a deconvolution module onboard (WinNonlin 5.2+, Kinetica, PDx-IVIVC) rely heavily on smoothing of data – but manufacturers rarely document the actual method in the manual. ![]() Good look! — 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 |
drcampos ★ Brazil, 2007-03-19 22:17 (6533 d 16:20 ago) @ Helmut Posting: # 589 Views: 41,362 |
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Helmut, Thank you for your prompt reply and the excel-sheet with detailed calculation. Therefore, the articles suggested and the explanation were very important to understand the principle of the numerical deconvolution. ![]() I have just requested the IVIVC module of WinNonlin to Pharsight. Best regards, Daniel Rossi de Campos Brazil |
Rayhope ☆ India, 2021-10-07 16:25 (1217 d 23:11 ago) @ Helmut Posting: # 22621 Views: 8,501 |
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❝ You may use my speadsheet as some kind of a sandbox: alter values, and watch… Dear Daniel, Is your excel sheet still available to start with? it will be great if you can share it. Regards, Ray. |
Helmut ★★★ ![]() ![]() Vienna, Austria, 2021-10-07 18:38 (1217 d 20:58 ago) @ Rayhope Posting: # 22622 Views: 8,316 |
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Hi Ray, ❝ Is your excel sheet still available to start with? it will be great if you can share it. If you would have looked at Daniel’s profile, you would have noticed that the last time he logged in was nine years ago. You can try to send him a PM. No idea whether the email he used in registration is still current. If that doesn’t work, I can ask him (my last contact was in April). — 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 |
Rayhope ☆ India, 2021-10-08 11:07 (1217 d 04:30 ago) @ Helmut Posting: # 22623 Views: 8,212 |
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❝ If you would have looked at Daniel’s profile, you would have noticed that the last time he logged in was nine years ago. You can try to send him a PM. No idea whether the email he used in registration is still current. ❝ ❝ If that doesn’t work, I can ask him (my last contact was in April). Sure I will ask Daniel. Thank you. |
Rayhope ☆ India, 2021-11-11 09:35 (1183 d 05:02 ago) @ Rayhope Posting: # 22671 Views: 7,684 |
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❝ ❝ If that doesn’t work, I can ask him (my last contact was in April). Hi, I tried to contact Daniel but I guess not active here. Can you ask him please. |
Dipesh Jayswal ● 2007-03-21 09:21 (6532 d 05:15 ago) @ Helmut Posting: # 590 Views: 41,349 |
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Dear HS, Please correct the year of the publication which u have prescribed in ur mail.
Regards, Dipesh |
Helmut ★★★ ![]() ![]() Vienna, Austria, 2007-03-21 13:13 (6532 d 01:24 ago) @ Dipesh Jayswal Posting: # 591 Views: 40,923 |
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Dear Dipesh, oops, thank you for the correction! — 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 |
jesse08 ● 2007-09-01 03:38 (6368 d 11:58 ago) @ Helmut Posting: # 1045 Views: 40,416 |
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Hi: Anyone know how to calculate the plasma profile using in vitro dissolution profile and IVIVC? i.e. in vivo absorption profile -> plasma profile Thanks. HMY |
Helmut ★★★ ![]() ![]() Vienna, Austria, 2007-09-01 16:49 (6367 d 22:48 ago) @ jesse08 Posting: # 1046 Views: 40,540 |
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Dear HMY! ❝ Anyone know how to calculate the plasma profile using in vitro dissolution profile and IVIVC? Yes. ![]() ❝ i.e. in vivo absorption profile -> plasma profile This is the concept of ‘Mapping’. You should have all tools given previously in this thread handy. Once you have an IVIVC established, it’s trivial to calculate in vivo dissolution and therefore predict the plasma profile. What is your question? — 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 |
jesse08 ● 2007-09-02 02:32 (6367 d 13:04 ago) @ Helmut Posting: # 1047 Views: 40,456 |
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❝ Once you have an IVIVC established, it’s trivial to calculate in vivo dissolution and therefore predict the plasma profile. ❝ What is your question? My question is once I have IVIVC, any software or program I can use to predict in vivo plasma profile (i.e. how to run the convolution? How to run the convolution in WinNonlin?) Thanks. HMY Edit: Full quote removed. Please see this post! [HS] |
Helmut ★★★ ![]() ![]() Vienna, Austria, 2007-09-02 14:03 (6367 d 01:34 ago) @ jesse08 Posting: # 1048 Views: 40,748 |
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Dear HMY! ❝ My question is once I have IVIVC, any software or program I can use to predict in vivo plasma profile (i.e. how to run the convolution? How to run the convolution in WinNonlin?) In WinNonlin you have two options:
Links to other software are given in this thread; Kinetica has IVIVC-Templates ‘onboard’. — 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 |
jesse08 ● 2007-10-03 04:13 (6336 d 11:23 ago) @ Helmut Posting: # 1150 Views: 41,672 |
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Hi: Did anyone compare the convolution results (i.e. predicted in vivo concentration profile) between Pharsight's IVIVC toolkit and MS-Excel method by Langenbucher's article: Handling of computational in vitro/in vivo correlation problems by Microsoft Excel: III. Convolution and deconvolution? Are the results similar? I am using the MS-Excel method now to do the convolution. I just want to make sure the IVIVC toolkit will produce the same results. HMY |
Nirali ★ India, 2007-11-21 13:38 (6287 d 00:59 ago) @ jesse08 Posting: # 1316 Views: 40,427 |
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Dear HS, I have WinNonlin 5.2 version with IVIVC kit. For IVIVC comparison WinNonlin ask minimum three formulation for comparison. I have only two formulations on hand ![]() Has WinNonlin any other way to compare two formulations ![]() Thanks & Regards, Nirali |
Helmut ★★★ ![]() ![]() Vienna, Austria, 2007-11-21 16:25 (6286 d 22:12 ago) @ Nirali Posting: # 1317 Views: 40,474 |
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Dear Nirali, ❝ I have WinNOnlin 5.2 version with IVIVC kit. How much did the IVIVC Toolkit cost? ❝ For IVIVC comparison WinNonlin ask minimum three formulation for comparison. You will need at least 3 data pairs for any type of linear dependency; this is not a WinNonlin-problem. Just imagine: In a linear regression you estimate two parameters – intercept and slope. With 3 data pairs, you have 1 degree of freedom left. With only 2 data pairs you have no degrees of freedom, or in other words you will always be able to draw a straight line, but getting no information on goodness of fit (coefficient of correlation = exactly one). ❝ I have only two formulation on hand Oh, that’s bad – no resolution possible, unless you come up with results from a 3rd formulation… — 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 |
Nirali ★ India, 2007-11-22 08:53 (6286 d 05:43 ago) @ Helmut Posting: # 1320 Views: 40,128 |
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Dear Helmut, Thank you. I will definitely get back to you if i have any query about IVIVC. ❝ How much did the IVIVC Toolkit cost? We purchase WinNonlin IVIVC toolkit in April 2007 and paid 3000$/user/single workstation. Warm Regards, Nirali |
Helmut ★★★ ![]() ![]() Vienna, Austria, 2007-11-22 10:53 (6286 d 03:44 ago) @ Nirali Posting: # 1323 Views: 40,308 |
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Dear Nirali, yesterday I was too fast in responding. ![]() Of course you need ≥3 formulations only for Level B-C correlations. If you were lucky enough to get a point-to-point correlation (Level A), even one formulation (+iv data) is enough. — 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 |
Nirali ★ India, 2007-11-27 07:05 (6281 d 07:32 ago) @ Helmut Posting: # 1335 Views: 40,145 |
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Dear Mr. Helmut, Yes you are right. I have little bit idea about level A correlation. I tried it in Excel using Wagner Nelson method. But here I am not able to perform IVIVC from WinNonlin due to lack of 3rd formulation. Is Level A correlation possible with WinNonlin? Then how? Friends, pls do share with me if you have exp of WinNonlin IVIVC. Thanks & Regards, Nirali |
SDavis ★★ ![]() UK, 2009-09-25 11:11 (5613 d 04:25 ago) @ Nirali Posting: # 4248 Views: 38,905 |
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Nirali, Sorry to resurrect an old thread but I just saw your question about "For IVIVC comparison WinNonlin ask minimum three formulation for comparison" and I am not sure I see where you get that message - it is recommended to have a minimum of 3 but you can build one with the you have or even 1, although of course you will have difficulty having confidence to go extrapolate in the PREDICTION tab, but the first 3 stages will work fine, that is IN VITRO fitting, IN VIVO fitting and CORRELATION — Simon Senior Scientific Trainer, Certara™ [link=https://www.youtube.com/watch?v=xX-yCO5Rzag[/link] https://www.certarauniversity.com/dashboard https://support.certara.com/forums/ |
sonu ☆ 2009-09-23 10:47 (5615 d 04:50 ago) @ Dipesh Jayswal Posting: # 4234 Views: 38,792 |
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