Background: A stability indicating high-performance thin layer chromatography (HPTLC)
method was developed for the evaluation of fisetin (FIS) in active pharmaceutical ingredient (API)
and marketed capsule formulation in accordance with the ICH guidelines.
Methods: The mobile phase combination toluene: ethyl acetate: formic acid: methanol (3: 5.5: 1: 0.5
v/v/v/v) was optimized with the aid of AQbD approach. The absorbance mode at 254 nm was chosen
for densitometric analysis as it gives a compact spot of FIS at Rf value of 0.74.
Results: The R2 value obtained from the linear regression equation of calibration plots made by taking
the spot in the concentration range of 100-1400 ng/spot was found to be 0.9993. The observed LOD
and LOQ value was found to be 29.8 ng/spot and 98.5 ng/spot, respectively. The exposure of FIS to
various stress conditions revealed the fact that the drug is stable in photochemical and dry heat stress
conditions without any degradation. The drug-exposed to acidic, alkaline and oxidative stress was
found to be degraded into different degradation products with the highest degradation was found in
alkaline stress. All degradation products were observed to be fairly separated from well-resolved parent
peak of FIS.
Conclusion: The developed HPTLC method have shown well-resolved peaks and also shown good
recovery in the compound FIS as well as FIS formulation.