A comparison of HPLC and bioassay methods for plasma melanotan-II (MT-II) determination: Application to a pharmacokinetic study in rats

✍ Scribed by Sydney O. Ugwu; James Blanchard; Linh D. Nguyen; Mac E. Hadley; Robert T. Dorr

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 395 KB
• Volume: 15
• Category: Article
• ISSN: 0142-2782
• DOI: 10.1002/bdd.2510150505

✦ Synopsis

The pharmacokinetic profile of the melanotropic peptide, melanotan-I1 (MT-II), was determined in rats following a 0.3 mg kg-I intravenous dose. Regression analysis of the plasma MT-I1 concentrations determined using HPLC and bioassay methods indicated the existence of a significant linear correlation (r=0-90, p<O.OOl). The plasma concentration versus time plots determined using the two assay methods yielded biphasic disposition profiles that were essentially superimposable. The following pharmacokinetic parameters were assessed from plasma concentration versus time data using both methods: C-, AUC, CL,, tIlw, MRT, Vd,, and V,. Statistical comparison showed that the parameters measured by each method were not significantly different (at the 0.05 level) except for t,,? MRT and V,. The presence of even one aberrant data point in the &phase can significantly influence t,lyp when only a few data points are available in the &phase. Since MRT and V, were calculated from tIlw it is not surprising that these two parameters also differed between methods.