Development and Validation of a Stability Indicating RP-HPLC Method for the Determination of Two Sun Protection Factors (Koptrizon and Tinosorb S) in Topical Pharmaceutical Formulations Using Experimental Designs
Table 2
Data of forced degradation study for Koptrizon and Tinosorb S.
Stress conditions
Koptrizon
Tinosorb S
PA
PTH
% Deg.
Purity flag
PA
PTH
% Deg.
Purity flag
Acidic hydrolysis
0.088
0.326
2.5
No
0.097
0.302
1.4
No
(5(N) HCl at 70°C, 5 hrs)
Alkaline hydrolysis
0.145
0.381
43.7
No
0.130
0.367
39.6
No
(5(N) NaOH at 70°C, 5 hrs)
Oxidation
0.076
0.311
14.5
No
0.094
0.299
9.2
No
(30% H2O2 at 70°C, 2 hrs)
Thermal exposed
0.071
0.306
ND
No
0.091
0.307
ND
No
(At 105°C, 6 hrs)
Photolytic exposed
0.089
0.341
ND
No
0.084
0.325
ND
No
(1.2 million lux hr visible light and 200 wh/m2 UV light)
