title: An improved validated ultra high pressure liquid chromatography method for separation of tacrolimus impurities and its tautomers.
abstract: A selective, specific and sensitive ultra high pressure liquid chromatography (UHPLC) method was developed for determination of tacrolimus degradation products and tautomers in the preparation of pharmaceuticals. The chromatographic separation was performed on Waters ACQUITY UPLC system and BEH C₈ column using gradient elution of mobile phase A (90:10 v/v of 0.1% v/v triflouroacetic acid solution and Acetonitrile) and mobile phase B (90:10 v/v acetonitrile and water) at a flow rate of 0.6 mL min⁻¹. Ultraviolet detection was performed at 210 nm. Tacrolimus, tautomers and impurities were chromatographed with a total run time of 25 min. Calibration showed that the response of impurity was a linear function of concentration over the range 0.3-6 µg mL⁻¹ (r² ≥ 0.999) and the method was validated over this range for precision, intermediate precision, accuracy, linearity and specificity. For precision study, percentage relative standard deviation of each impurity was < 15% (n = 6). The method was found to be precise, accurate, linear and specific. The proposed method was successfully employed for estimation of tacrolimus impurities in pharmaceutical preparations.
authors.affiliation: Dr Reddy's Laboratories Ltd, Generics AR&D, Bachupalli, Qutubllapur, AP, India. subasranjana@drreddys.com
authors.forename: Acharya
authors.initials: A
authors.lastname: Subasranjan
authors.forename: Srinivasulu
authors.initials: S
authors.lastname: C
authors.forename: Raoutray
authors.initials: R
authors.lastname: Hemant
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D056148:Chromatography, Reverse-Phase; D004340:Drug Contamination; D006358:Hot Temperature; D006868:Hydrolysis; D007536:Isomerism; D015394:Molecular Structure; D010084:Oxidation-Reduction; D004364:Pharmaceutical Preparations / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D016559:Tacrolimus / Q000031:analogs & derivatives* / Q000302:isolation & purification* / Q000378:metabolism / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D004364:Pharmaceutical Preparations; D016559:Tacrolimus