We described a simple and rapid method to quantify simultaneously chlorhexidine (CHD) and its major metabolite, para Chloroaniline (pCA) by HPLC with UV detection without the additional need of mobile-phase amine modifiers or ion-pairing reagents, with good resolution between pCA and CHD, symmetry peak of the compound and short run time. HPLC-UV analyses were performed using a Dionex® Summit liquid chromatograph (Dionex Corp, Sunnyvale, CA, USA). Chromatographic separations were carried out on a Luna® 150 mm×3 mm i.d. column packed with 3 µm CN (cyano) particles (Phenomenex®), guarded by an on-line filter. Mobile phase consist of methanol:water with sodium chloride with 0.02% of formic acid (55:45). Wavelengths for pCA and for CHD are 238 and 255 nm respectively. Influence of methanol and of sodium chloride content in the eluant has been studied. Linearity of CHD is very good, from 0.5 up to 21.2 µg/l while linearity of pCA is in the range of 0.05 to 10 µg/l with correlation coefficients above 0.999. Resolution between the components is above 4, asymmetry is about 1.3 and 1.7 for pCA and CHD respectively and the run time is less than 5 minutes. This method has been applied to CHD solution of different medical devices. No interference has been reported, and the analysis of direct injection of solution, without any treatment is achieved in less than five minutes.In conclusion, we present a validated method for dosage of CHD and its major impurity pCA, known to be carcinogen, available into medical products or medicinal device for in-vitro diagnostic.

BackgroundA clinical trial sponsored by our hospital wished to compare HMG-CoA reductase inhibitors versus placebo for children with genetic diseases. For this purpose, and because the dosage in unavailable, our laboratory is in charge of the galenic development of simvastatin capsules and its placebo. According to GMP, the stability of the simvastatin capsule is evaluated.PurposeDevelopment and validation of a stability indicating HPLC-UV method for simvastatin capsules.Material and methodsThe HPLC system is a Thermofisher P4000. The column is an inertsil-CN, 250×4.6 mm with 5 µm particle. The mobile phase is an isocratic elution made up of 0.1% acetic acid buffer/methanol (50:50 v/v) at 1 mL/min flow rate. λ is included between 200 and 400 nm. Maximal absorbance of simvastatin is 237 nm. Calibration standard curve is between 30 and 70 µg/mL. Niacin is used as the internal standard. Linearity, trueness, accuracy and limits of quantification were evaluated according to SFSTP recommendations. Impurities were searched from SCR impurities of simvastatin dust according to pharmacopoeia 8.0. The matrix effect was evaluated.ResultsLinearity for simvastatin was validated with r² >0.99 and SD <15%. Recoveries and bias were < 15% for each validation standard. High and low limits of detections were far from the calibration standard curves. There was no matrix effect with the excipients. All impurities were detected and separated with a resolution >1.5.ConclusionA simple and rapid stability indicating HPLC-UV method was developed and validated according to ICH and SFSTP international recommendations. It will be used to evaluate the stability of our simvastatin capsule. We already have 3 months of validated stability.No conflict of interest