Development and validation of a RP-HPLC method for the simultaneous detection and quantification of simvastatin's isoforms and coenzyme Q10 in lecithin/chitosan nanoparticles

Hybrid nanocapsules constituted of phospholipids and polysaccharides have been proposed as colloidal systems for the delivery of drugs via non-parenteral administration routes, due their capacity of high drug loading, controlled drug release and targeted delivery to the specific organ. Moreover, nanoparticles systems offer the possibility of co-encapsulation of drugs in the same drug delivery system and, consequently, the simultaneous administration of compounds. Characterization of nanoparticles properties, specifically involves quantification of the active pharmaceutical ingredients and is pivotal in the development of innovative nanomedicines. Therefore, this study has proposed and validated a new RP-HPLC-UV method for the simultaneous determination of simvastatin and coenzyme Q10 in hybrid nanoparticles systems. A reversed phase (RP) C8 column and a gradient elution of water: methanol at flow rate of 1.5 ml/min was used. Simvastatin (SVT), simvastatin hydroxyacid isoform (SVA) and coenzyme Q10 were identified by dual wavelength-UV detection at 238 nm (statins) and 275 nm, respectively. The proposed method was selective and linear in the range of 0.5-25 μg/ml (r2 > 0.999), precise, with values of relative standard deviation (RSD) lower than 2%, robust and accurate (recovery values of 100 ± 5%), satisfying FDA guidelines. Furthermore, low detection (LOD <0.2 μg/ml) and quantification limits (LOQ <0.4 μg/ml) were suitable for the application of the method for the in vitro study of release kinetics of simvastatin and coenzyme Q10 co-encapsulated in lecithin/chitosan nanoparticles. The proposed method represents, to our knowledge, the only method for the simultaneous quantification of simvastatin, coenzyme Q10 and of the hydrolysed hydroxyacid isoform of the statin in nanoparticles.