Crouch Dennis J
University of Utah, Salt Lake City, UT 84112, USA.
Forensic Sci Int. 2005 Jun 10;150(2-3):165-73. doi: 10.1016/j.forsciint.2005.02.028.
The potential to use oral fluid as a drug-testing specimen has been the subject of considerable scientific interest. The ease with which specimens can be collected and the potential for oral fluid (OF) drug concentrations to reflect blood-drug concentrations make it a potentially valuable specimen in clinical as well as forensic settings. However, the possible effects of the OF collection process on drug detection and quantification has often been over looked. Several studies have documented that drug-contamination of the oral cavity may skew oral fluid/blood drug ratios and confound interpretation when drugs are smoked, insufflated or ingested orally. OF pH is predicted to have an effect on the concentration of drugs in OF. However, in a controlled clinical study, the effect of pH was less than that of collection technique. Mean codeine OF concentrations in specimens collected a non-stimulating control method were 3.6 times higher than those in OF collected after acidic stimulation. Mean codeine concentrations were 50% lower than control using mechanical stimulation and 77% of control using commercial collection devices. Several factors should be considered if a commercial OF collection device is used. In vitro collection experiments demonstrated that the mean collection volume varied between devices from 0.82 to 1.86 mL. The percentage of the collected volume that could be recovered from the device varied from 18% to 83%. In vitro experiments demonstrated considerable variation in the recovery of amphetamines (16-59%), opiates (33-50%), cocaine and benzoylecgonine (61-97%), carboxy-THC (0-53%) and PCP (9-56%). Less variation in collection volume, volume recovered and drug recovery was observed intra-device. The THC stability was evaluated in a common commercial collection protocol. Samples in the collection buffer were relatively stable for 6 weeks when stored frozen. However, stability was marginal under refrigerated conditions and poor at room temperature. Very little has been published on the efficacy of using IgG concentration, or any other endogenous marker, as a measure of OF specimen validity. Preliminary rinsing experiments with moderate (50 mL and 2 x 50 mL) volumes of water did not reduce the OF IgG concentration below proposed specimen validity criteria. In summary, obvious and more subtle variables in the OF collection may have pronounced effects on OF-drug concentrations. This has rarely been acknowledged in the literature, but should to be considered in OF drug testing, interpretation of OF-drug results and future research studies.
将口腔液用作药物检测样本的潜力一直是相当多科学研究的主题。样本采集的便捷性以及口腔液（OF）药物浓度反映血药浓度的可能性，使其在临床和法医环境中成为一种潜在的有价值样本。然而，OF采集过程对药物检测和定量的可能影响常常被忽视。多项研究表明，当药物通过吸烟、吸入或口服进入口腔时，口腔的药物污染可能会扭曲口腔液/血药比例并混淆解读。预计OF的pH值会对OF中的药物浓度产生影响。然而，在一项对照临床研究中，pH值的影响小于采集技术的影响。采用非刺激对照方法采集的样本中可待因的OF平均浓度比酸性刺激后采集的OF中的浓度高3.6倍。使用机械刺激时可待因的平均浓度比对照低50%，使用商用采集装置时比对照低77%。如果使用商用OF采集装置，应考虑几个因素。体外采集实验表明，不同装置的平均采集体积在0.82至1.86 mL之间变化。从装置中可回收的采集体积百分比在18%至83%之间变化。体外实验表明，苯丙胺（16 - 59%）、阿片类药物（33 - 50%）、可卡因和苯甲酰爱康宁（61 - 97%）、羧基 - THC（0 - 53%）和苯环己哌啶（9 - 56%）的回收率存在相当大的差异。在同一装置内观察到的采集体积、回收体积和药物回收率的变化较小。在一种常见的商用采集体检中评估了THC的稳定性。采集缓冲液中的样本冷冻保存时相对稳定6周。然而，在冷藏条件下稳定性一般，在室温下稳定性较差。关于使用IgG浓度或任何其他内源性标志物作为衡量OF样本有效性的方法的功效，发表的内容很少。用适量（50 mL和两个50 mL）水进行的初步冲洗实验并未使OF中的IgG浓度降至建议的样本有效性标准以下。总之，OF采集中明显和更细微的变量可能对OF药物浓度有显著影响。这在文献中很少被提及，但在OF药物检测、OF药物结果解读和未来研究中应予以考虑。
