Determination of neomycin sulfate and impurities using high-performance anion-exchange chromatography with integrated pulsed amperometric detection.

摘要: Neomycin B is one of a class aminoglycoside antibiotics that lack good chromophore, and therefore difficult to determine using reversed-phase HPLC with absorbance detection. This especially true for determining the quantity each impurity. We show neomycin sulfate its major impurities, including neamine (neomycin A), can be separated on strong anion-exchange column weak potassium hydroxide eluent (2.40 mM) at temperature 30 degrees C, directly detected by integrated pulsed amperometric detection (IPAD). The resolution (United States Pharmacopeia (USP) definition) between closest impurity ranged from 6.56 7.45 over 10 days consecutive analysis (7.24+/-0.10, n=836 injections). Due difficulty producing eluents required purity (i.e. carbonate-free), this method depends automatic generation ensure ruggedness. exhibited long-term (10 days, 822 injections) retention time stability R.S.D. 0.6%. Peak area microM) was 1.3%. Method robustness evaluated intentionally varying flow rate, concentration, temperature, column. spike recoveries extractions three different topical ointments cream formulations 95 100%. measured concentration in these 119 154% label concentration. tested separate n=11 extracts, 3.2%. Based results evaluations, we believe used identity, assay, purity.