Wu Zimei, Tucker Ian G, Razzak Majid, Medlicott Natalie J
School of Pharmacy, University of Otago, P.O. Box 913, Dunedin, New Zealand.
Int J Pharm. 2005 Nov 4;304(1-2):1-3. doi: 10.1016/j.ijpharm.2005.08.012. Epub 2005 Sep 29.
A simple in vitro method for the detection of precipitation using 96-well microplates and a SpectraMax Plus microtiter plate reader has been developed and described. The method requires only small amount of drug and is, therefore, potentially applicable in early pre-formulation. The method is based on opacity changes that occur with precipitation and yields several descriptive parameters, onset time (Tonset), maximum rate (Vmax) and the time to reach Vmax (Tmax). Using these parameters, potential parenteral formulations can be ranked by their tendency to precipitate on dilution. We report use of this method and ranking of potential formulations of ricobendazole (RBZ), a poorly soluble anthelmintic, in various solvent systems. Detection at 500 nm was more sensitive than a wavelength of 550 nm and increased temperature (37 degrees C compared with 25 degrees C) accelerated precipitation. Results demonstrated the method was simple, descriptive and objective in the detection of precipitation of ricobendazole formulation on dilution and pH shift.
已开发并描述了一种使用96孔微孔板和SpectraMax Plus酶标仪进行沉淀检测的简单体外方法。该方法仅需少量药物，因此可能适用于早期制剂前研究。该方法基于沉淀时发生的浊度变化，并产生几个描述性参数，起始时间（Tonset）、最大速率（Vmax）和达到Vmax的时间（Tmax）。利用这些参数，可以根据潜在注射剂在稀释时沉淀的倾向对其进行排序。我们报告了该方法的使用以及在各种溶剂系统中对难溶性驱虫药利可苯达唑（RBZ）潜在制剂的排序。在500 nm处检测比在550 nm波长处更灵敏，升高温度（37℃与25℃相比）会加速沉淀。结果表明，该方法在检测利可苯达唑制剂在稀释和pH值变化时的沉淀方面简单、具有描述性且客观。
