Spectrofluorimetry and First derivative ratio of ratio spectroscopy.

Four simple, accurate and precise methods have been developed and validated for the determination of cisatracurium besylate in bulk and in its pharmaceutical preparation. The first method was a spectrofluorimetric method based on measuring the native fluorescence intensity (FI) of cisatracurium (CIS) in aqueous micellar medium at 317 nm upon excitation at 235 nm in the range of 0.2- 2.2 µg.mL-1. The other three methods were adopted for the determination of the studied drug in the presence of its alkaline degradation product including a spectrophotometric method namely, first derivative of ratio spectra (DD1) in the range of 8-38 µg.mL-1 and two high pressure liquid chromatographic (HPLC) methods, one with diode –array detector (DAD) and the other with fluorescence detector (FLD) in the ranges of 1.0- 40.0 µg.mL-1 and 0.25-20.0 µg.mL-1, respectively. Separation was achieved on Supelco Discovery®C18 column (150 mm x 4.6 mm, 5 µm) and Agilent Zorbax® SB- CN column (50 mm x 4.6 mm, 1.8 µm) for HPLC - DAD and HPLC- FLD methods, respectively. All the proposed methods were validated and successfully applied for the determination of CIS in bulk and in pharmaceutical preparation with good recovery ranges between 99.92- 100.71. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer method, and no significant difference was found.