A HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR THE DETERMINATION OF LJP 394 IN PLASMA AND SERUM.

L. Leggett*, R. Hayden, P. Chieng, La Jolla Pharmaceutical Company, San Diego, CA 92121 USA, and D. Dadgar, F. Vazvaei*, L. Cojocaru and R. Lucherini; Phoenix International Life Sciences, Montreal, Canada, H4R 2N6.

A robust and sensitive method was developed to quantitate an investigational new oligonucleotide (LJP 394), a treatment for Systemic Lupus Erythematosus (SLE) and associated renal disease, by HPLC/UV, utilizing a column switching technique. The method was based on online solid phase extraction using a Dionex Nucleopac PA-100 (2x10 mm) concentration column. Plasma or serum was filtered (MSI, Nylon, 0.22 m) prior to application onto the concentration column. Proteins and interfering compounds were washed to waste with a gradient mixture of:

a) (25 mM tris pH 7.4)/ACN/MeOH (85/10/5)

b) (25 mM tris pH 7.4, 1 M NaCl)/ACN/MeOH (85/10/5)

After 8 minutes the switching valve was activated to allow the elution of LJP 394 from the concentration column onto a Dionex Nucleopac PA-100 (2x250 mm) analytical column. The method was validated with a quantitation range of 10-1000 ng/mL in both human serum and plasma as well as 10-2600 mg/mL in monkey plasma. Validation data including within and between-batch precision accuracy, recovery and different types of stability studies will be presented. The method has been successfully applied to a variety of samples.

Presented at the Annual Meeting of the American Association of Pharmaceutical Scientists, Oct. 27-31, 1996, Seattle, WA.