Loveless Vivian S, Surdock Christopher P, Bhattacharjee Himanshu
Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center-Memphis, Memphis, Tennessee, USA.
J Nucl Med Technol. 2010 Mar;38(1):49-52. doi: 10.2967/jnmt.109.068973. Epub 2010 Feb 16.
The use of (99m)Tc-sulfur colloid lymphoscintigraphy for the determination of lymph flow patterns from a tumor site and localization of the sentinel node has been widely adopted. However, the effects of multiple injections of the radiopharmaceutical can range from mild discomfort to pain. pH-adjusted lidocaine HCl coadministered with (99m)Tc-sulfur colloid presents a risk of introducing instability of the radiopharmaceutical, which could lead to aggregation, possibly impeding the kinetics of lymphatic drainage from the tumor site.
In the present study, lidocaine pH-adjusted with 4.2%, 6.3%, or 8.4% sodium bicarbonate was added to the (99m)Tc-sulfur colloid radiopharmaceutical to monitor effects on radiochemical purity, zeta-potential, particle size, and pH. These parameters were then used to evaluate the short-term stability of the preparation.
The study revealed that the formulation of lidocaine pH-adjusted with 8.4% sodium bicarbonate added to (99m)Tc-sulfur colloid demonstrated a similar change in zeta-potential (-4.09 +/- 2.90 mV) and particle size (10-330 nm) to that of control filtered (99m)Tc-sulfur colloid (-5.09 +/- 1.68 mV and 11-343 nm, respectively). However, the 4.2% preparation showed a zeta-potential of -3.01 +/- 2.24 mV and a particle size range of 10-351 nm. The pH of the 8.4% buffered preparation, at 7.1, was closer to physiologic pH than was the control, at 6.0. The 6.3% pH-adjusted lidocaine-(99m)Tc-sulfur colloid preparation failed radiochemical purity; thus, it was not included in the analysis.
Compared with other (99m)Tc-sulfur colloid test formulations of 4.2% and 6.3% pH-adjusted lidocaine, the 8.4% sodium bicarbonate pH-adjusted lidocaine-(99m)Tc-sulfur colloid preparation, taken as a whole, yielded superior quality-control parameters. This formulation would be an acceptable alternative to the control.
使用（99m）锝-硫胶体淋巴闪烁显像术来确定肿瘤部位的淋巴引流模式和前哨淋巴结的定位已被广泛采用。然而，多次注射放射性药物的影响范围从轻度不适到疼痛。与（99m）锝-硫胶体共同给药的经pH调节的盐酸利多卡因存在导致放射性药物不稳定的风险，这可能会导致聚集，有可能阻碍肿瘤部位的淋巴引流动力学。
在本研究中，将用4.2%、6.3%或8.4%碳酸氢钠调节pH的利多卡因添加到（99m）锝-硫胶体放射性药物中，以监测对放射化学纯度、ζ电位、粒径和pH的影响。然后使用这些参数来评估制剂的短期稳定性。
研究表明，添加到（99m）锝-硫胶体中的用8.4%碳酸氢钠调节pH的利多卡因制剂，其ζ电位（-4.09±2.90 mV）和粒径（10 - 330 nm）的变化与对照过滤后的（99m）锝-硫胶体（分别为-5.09±1.68 mV和11 - 343 nm）相似。然而，4.2%的制剂显示ζ电位为-3.01±2.24 mV，粒径范围为10 - 351 nm。8.4%缓冲制剂的pH为7.1，比对照的pH 6.0更接近生理pH。6.3%经pH调节的利多卡因-（99m）锝-硫胶体制剂放射化学纯度不合格；因此，未纳入分析。
与其他4.2%和6.3%经pH调节的利多卡因的（99m）锝-硫胶体测试制剂相比，整体而言，用8.4%碳酸氢钠调节pH的利多卡因-（99m）锝-硫胶体制剂产生了更好的质量控制参数。该制剂将是对照的可接受替代物。
