Number of days
stored

0.25 µg/ml

2.5 µg/ml

 20 µg/ml

Mean ± SD
(n = 3)

% C.V.

Mean ± SD
(n = 3)

% C.V.

Mean ± SD
(n = 3)

% C.V.

3-Freeze thaw studies

0.247±0.006

2.341

2.493±0.042

1.670

20.280±0.061

0.300

5 days

0.237±0.006

2.440

2.413±0.055

2.282

19.770±0.123

0.622

15 days

0.227±0.015

6.739

2.327±0.057

2.444

19.607±0.155

0.792

30 days

0.220±0.01

4.545

2.217±0.05

2.271

19.397±0.157

0.809