Development and validation of a rapid HPLC method for the quantification of GSE4 peptide in biodegradable PEI–PLGA nanoparticles

• An HPLC method was validated for the determination of GSE4-loaded nanoparticles.
• The method is specific, linear, precise, and accurate within the range 10–100 μg/ml.
• GSE4 was stable for 48 h at 5 °C as standard solution or extracted form nanoparticles.
• The method is simple, fast and easy to apply for quality control routine analysis.

In this work a high performance liquid chromatographic (HPLC) method has been developed and validated for the content determination of GSE4 peptide in PEI–PLGA nanoparticles. Chromatographic separation was performed on a C18 column, and a gradient elution with a mobile phase composed of methanol and 0.1% aqueous trifluoroacetic acid (TFA) solution, at a flow rate of 1 ml/min, was used. GSE4 peptide identification was made by fluorescence detection at 290 nm. The elution of methanol:TFA was initially maintained at (20:80, v/v) for one min and the gradient changed to (80:20, v/v) in 6 min. This ratio was then followed by isocratic elution at (80:20, v/v) during another min and for further 3 min it was linearly modified to (20:80, v/v). The developed method was validated according to the ICH guidelines, being specific, linear in the range 10–100 μg/ml (R2 = 0.9996), precise, exhibiting good inter-day and intra-day precision reflected by the relative standard deviation values (less than 3.88%), accurate, with a recovery rate of 100.18 ± 0.95%, and stable for 48 h at 5 °C or at RT when encapsulated in nanoparticles. The method was simple, fast, and successfully used to determine the peptide content in GSE4-loaded PEI–PLGA nanoparticles.