Texas A&M University Health Science Center Rangel College of Pharmacy - Pharmaceutical Sciences, MSC 131 1010 West Avenue B, Kingsville, TX 78363-8202, USA.
Texas A&M University Health Science Center Rangel College of Pharmacy - Pharmaceutical Sciences, Kingsville, TX, USA.
Ther Adv Drug Saf. 2014 Oct;5(5):180-9. doi: 10.1177/2042098614543091.
The accessibility of prescription drugs produced outside of the United States, most notably sildenafil citrate (innovator product, Viagra®), has been made much easier by the Internet. Of greatest concern to clinicians and policymakers is product quality and patient safety. The US Food and Drug Administration (FDA) has issued warnings to potential buyers that the safety of drugs purchased from the Internet cannot be guaranteed, and may present a health risk to consumers from substandard products.
The objective of this study was to determine whether generic sildenafil citrate tablets from international markets obtained via the Internet are equivalent to the US innovator product regarding major aspects of pharmaceutical quality: potency, accuracy of labeling, and presence and level of impurities. This will help identify aspects of drug quality that may impact public health risks.
A total of 15 sildenafil citrate tablets were obtained for pharmaceutical analysis: 14 generic samples from international Internet pharmacy websites and the US innovator product. According to US Pharmacopeial guidelines, tablet samples were tested using high-performance liquid chromatography for potency of active pharmaceutical ingredient (API) and levels of impurities (impurities A, B, C, and D). Impurity levels were compared with International Conference on Harmonisation (ICH) limits.
Among the 15 samples, 4 samples possessed higher impurity B levels than the ICH qualification threshold, 8 samples possessed higher impurity C levels than the ICH qualification threshold, and 4 samples possessed more than 1% impurity quantity of maximum daily dose (MDD). For API, 6 of the samples failed to fall within the 5% assay limit.
Quality assurance tests are often used to detect formulation defects of drug products during the manufacturing and/or storage process. Results suggest that manufacturing standards for sildenafil citrate generic drug products compared with the US innovator product are not equivalent with regards to potency and levels of impurities. These findings have implications for safety and effectiveness that should be addressed by clinicians to safeguard consumers who choose to purchase sildenafil citrate and foreign-manufactured drugs, in general, via the Internet.
由于互联网的便利性，从美国境外生产的处方药，尤其是枸橼酸西地那非（原研药，伟哥）更容易获得。令临床医生和政策制定者最担忧的是产品质量和患者安全。美国食品和药物管理局（FDA）已向潜在买家发出警告，称无法保证从互联网购买的药品的安全性，并且来自低质量产品的药品可能对消费者的健康构成风险。
本研究的目的是确定通过互联网从国际市场获得的枸橼酸西地那非普通片剂在药物质量的主要方面是否与美国原研产品等效：效力、标签准确性以及杂质的存在和水平。这将有助于确定可能影响公共健康风险的药物质量方面。
共获得 15 片枸橼酸西地那非进行药物分析：14 个来自国际互联网药店网站和美国原研产品的通用样本。根据美国药典指南，使用高效液相色谱法对片剂样品进行活性药物成分（API）的效力和杂质（杂质 A、B、C 和 D）水平的测试。杂质水平与国际协调会议（ICH）的限制进行了比较。
在 15 个样本中，4 个样本的杂质 B 水平高于 ICH 合格阈值，8 个样本的杂质 C 水平高于 ICH 合格阈值，4 个样本的杂质最大日剂量（MDD）超过 1%。对于 API，有 6 个样本未能落在 5%的测定范围内。
质量保证测试常用于检测药品在制造和/或储存过程中的制剂缺陷。结果表明，枸橼酸西地那非普通药物产品与美国原研产品的制造标准在效力和杂质水平方面并不等效。这些发现对安全性和有效性有影响，临床医生应加以解决，以保护选择通过互联网购买枸橼酸西地那非和外国制造药品的消费者。
