A new chromatographic-densitometric method has been developed for the 
qualitative and quantitative determination of the active ingredients in a 
simulated mixture corresponding to the PolyIran polypill, composed of 
acetylsalicylic acid, hydrochlorothiazide (HCT), enalapril (ENA), and 
atorvastatin (ATR), whose efficacy in the treatment and prevention of 
cardiovascular disease has been documented in clinical trials. Chromatographic 
separation was performed using TLC silica gel 60 plates with fluorescent 
indicator F254 as the stationary phase and a mixture of n-hexane-ethyl 
acetate-methanol-water-acetic acid (8.4 + 8 + 3 + 0.4 + 0.2, v/v/v/v/v) as the 
mobile phase. Densitometric measurements were carried out at λ = 210 nm when 
determining ENA and at λ = 265 nm in the case of the other drugs. Peaks of 
examined substances were well separated in the recorded chromatograms, enabling 
the evaluation of the results in terms of both qualitative and quantitative 
analysis. The method was specific for the analyzed components and was 
characterized by high sensitivity. The LOD was between 0.043 and 0.331 μg/spot, 
and LOQ was between 0.100 and 0.942 μg/spot. Recovery was in the range of 
97.02-101.34%. The linearity range was broad and ranged from 0.600 to 6.000 
μg/spot for acetylsalicylic acid, from 0.058 to 1.102 μg/spot for HCT, from 
0.505 to 6.560 μg/spot for ENA, and from 0.100 to 1.000 μg/spot for ATR. The 
method was characterized by good precision, with RSD values that ranged from 
0.10 to 2.26%.