Stereo-specific analysis of a novel protein kinase C inhibitor

SPC-100270 drug substance ((2S,3S)-2-aminooctadecane-1,3-diol) is a synthetic sphingosine analogue possessing limited ultraviolet absorbance (UV) and two chiral centres. Analytical methodology employing derivatization of SPC-100270 with o-phthaldialdehyde (OPA) and a chiral thiol, N-acetyl-D-penicillamine, was developed to assess the isomeric purity of SPC-100270 in the presence of two of its three stereoisomers. Separation of the isoindole derivatives was achieved with isocratic reversed-phase column chromatography with detection at 330 nm. Under the conditions studied, the derivatization was complete within 3 h at 50°C. The standard and derivatized solutions were stable for 7 days under refrigerated conditions. The limit of detection was 0.036 μg SPC-100270 per ml and the limit of quantitation was 0.237 μg SPC-100270 per ml. The assay response was linear over a concentration range of 4.7–376 μg SPC-100270 per ml with a coefficient of determination of greater than 0.9999. The precision, ruggedness and specificity of the assay were acceptable for determination of SPC-100270 in the presence of its stereoisomers and under forced degradation conditions. The method has been applied successfully in two independent laboratories for quality control release and stability assessment of SPC-100270 drug substance for early clinical studies.