Wagner-Nelson, Loo-Riegelman [Dissolution / BCS / IVIVC]

posted by Helmut Homepage – Vienna, Austria, 2007-03-16 16:39 (6034 d 09:03 ago) – Posting: # 583
Views: 38,498

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.
  1. Estimate kel from t=15 to t=32: 0.1271
  2. Calculate the partial AUCs (column 3)
  3. Calculate amount excreted / central volume of distribution:
    column 4 = column 3 x kel
  4. Calculate amount absorbed / central volume of distribution:
    column 5 = column 2 + column 4
  5. Calculate %absorbed:
    column 6 = column 5 / asymptotic plateau (estimated as mean from t=15 to t=32: 9.976)
┌────┬──────┬───────┬───────┬───────┬──────┐
│ c1 │  c2  │   c3  │   c4  │   c5  │  c6  │
├────┼──────┼───────┼───────┼───────┼──────┤
│  t │ C(t) │ AUC(t)│ Ae/Vp │ Aa/Vp │ %abs │
├────┼──────┼───────┼───────┼───────┼──────┤
│  0 │  –   │   –   │   –   │   –   │ 0.00 │
│  1 │ 2.28 │  1.14 │  0.14 │  2.42 │ 0.24 │
│  2 │ 3.69 │  4.13 │  0.52 │  4.21 │ 0.42 │
│  3 │ 5.52 │  8.73 │  1.11 │  6.63 │ 0.66 │
│  4 │ 5.52 │ 14.25 │  1.81 │  7.33 │ 0.73 │
│  5 │ 5.08 │ 19.55 │  2.49 │  7.57 │ 0.76 │
│  6 │ 4.91 │ 24.55 │  3.12 │  8.03 │ 0.80 │
│  8 │ 4.10 │ 33.56 │  4.27 │  8.37 │ 0.84 │
│ 10 │ 3.38 │ 41.04 │  5.22 │  8.60 │ 0.86 │
│ 12 │ 3.33 │ 47.75 │  6.07 │  9.40 │ 0.94 │
152.66 │ 56.73 │  7.21 │  9.87 │ 0.99 │
240.80 │ 72.30 │  9.19 │  9.99 │ 1.00 │
280.49 │ 74.88 │  9.52 │ 10.01 │ 1.00 │
320.31 │ 76.48 │  9.72 │ 10.03 │ 1.01 │
└────┼──────┼───────┴───────┼───────┼──────┘
     │0.1271│               │  9.976│
     └──────┘               └───────┘


❝ … 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.
  1. Wagner JG, Nelson E. Per Cent Absorbed Time Plots Derived from Blood Level and / or Urinary Excretion Data. J Pharm Sci. 1965; 52: 610–1.
  2. Loo JCK, Riegelman S. New Method for Calculating the Intrinsic Absorption Rate of Drugs. J Pharm Sci. 1968; 57: 918–28.

Dif-tor heh smusma 🖖🏼 Довге життя Україна! [image]
Helmut Schütz
[image]

The quality of responses received is directly proportional to the quality of the question asked. 🚮
Science Quotes

Complete thread:

UA Flag
Activity
 Admin contact
22,759 posts in 4,775 threads, 1,627 registered users;
12 visitors (0 registered, 12 guests [including 8 identified bots]).
Forum time: 02:43 CEST (Europe/Vienna)

A refund for defective software might be nice,
except it would bankrupt the entire software industry
in the first year.    Andrew S. Tanenbaum

The Bioequivalence and Bioavailability Forum is hosted by
BEBAC Ing. Helmut Schütz
HTML5