Bioequivalence and Bioavailability Forum • Lag Time Manual Calculation

Pankaj Bhangale
☆

India,
2011-09-05 11:30
(5054 d 17:15 ago)

Posting: # 7334
Views: 6,445

Lag Time Manual Calculation [PK / PD]

Dear All,

Please anyone can guide me, how to calculate lag time from subject concentration data vs time? I want manual calculation of lag time.

Following is example to calculate lag time.


Time  Concentration

(Hrs)   (ng/mL)

 0.00    0.00

 1.00    1.79

 2.00    3.48

 3.00    4.42

 3.50    4.44

 4.00    4.72

 4.33    5.12

 4.67    5.45

 5.00    4.92

 5.33    4.45

 6.00    4.12

 8.00    3.03

10.00    2.07

12.00    1.65

24.00    0.64

36.00    0.20

48.00    0.00

72.00    0.00

What is significance & interpretation of lag time in BE study? and Is there any correlation occurred between tmax & lag time?

Please Help me

Best Regards,
PANKAJ BHANGALE

Helmut
★★★

Vienna, Austria,
2011-09-05 15:15
(5054 d 13:30 ago)

@ Pankaj Bhangale
Posting: # 7335
Views: 5,506

Lag Time Manual Calculation

Post reply

Dear Pankay,

❝ Please anyone can guide me, how to calculate lag time from subject concentration data vs time? I want manual calculation of lag time.

Come up with a suitable definition of t_lag (sounds trivial, but isn’t; see below).
Select an algorithm.
Perform the calculation.

For some background search the forum; read the posts and references given in them.

❝ What is significance & interpretation of lag time in BE study?

T_lag plays some role in enteric coated (gastric resistant) formulations (examples: PPIs, diclofenac). With these types of formulations you may expect a lot of variability – not caused by the formulation itself, but due to gastric emptying.

❝ Is there any correlation occurred between tmax & lag time?

Partly. If the coating ‘works’ similar in both formulations and k_a is also similar you should get a good correlation. If one of these are different you would need PK modeling which is not acceptable in BE studies… :-D

—
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

Pankaj Bhangale ☆ India, 2011-09-06 11:49 (5053 d 16:56 ago) @ Helmut Posting: # 7336 Views: 5,309	Lag Time Manual Calculation Post reply
	Dear Helmut, Very thank you for the quick reply with information. Best Regards, Pankaj Bhangale