SOME OBSERVATIONS ON THE ADSORPTION OF TETRACYCLINES TO GLASS AND PLASTIC LABWARE

The binding of six tetracyclines to borosilicate glass or polypropylene test tubes was studied in vitro, and included chlorotetracycline, demeclocycline, doxycycline, minocycline, oxytetracycline, and tetracycline. All tetracyclines bound to borosilicate glass test tubes, and minocycline bound the most. Both time for binding to occur, and exposure to increasing amounts of surface area were involved in the production of increased binding, but the binding was mostly due to surface area. Doxycycline and minocycline significantly bound to polypropylene test tubes, whereas all of the other tetracyclines did not. This study suggests that all containers should be tested for possible binding of tetracyclines before use, and polypropylene labware is less likely to bind tetracyclines, compared to borosilicate glass. © 1990.