Background: The number of nanoproducts on the market will increase in the next years. The
development of analytical methods comprising conventional and novel pharmaceutical dosage forms and
drug delivery, under same conditions in order to save money, time and to reduce the environmental impact
of residues, is demanding.
Objective: The aim of this study was to develop a high performance liquid chromatography (HPLC)
method to assay doxazosin in polymeric nanocapsules and tablets under the same chromatographic conditions.
Method: As stationary phase, a reversed-phase column C-18 was used. The mobile phase was composed
of a mixture of acetonitrile, acidified water (80:20 v/v). Detection was performed at 248 nm. Validation
analysis were carried out according to the official requirements.
Results: A linear relationship was observed between the concentration of doxazosin and the chromatographic
area in the range between 5 and 40 μg.mL-1. The limits of quantification and detection were
0.756 and 0.252 μg.mL-1, respectively. The method was precise (intra- and inter-day), showing values of
relative standard deviation below 2%. Accuracy was demonstrated in the mean doxazosin recovery values
of 98% for nanocapsules and 95% for tablets.
Conclusion: This simple and inexpensive method may be used to determine doxazosin in nanocapsule
suspension as well tablets, under identical chromatographic conditions.