过氧化氢空间消毒技术(3)
其他

文章转自公众号:制剂车间

01 过氧化氢的腐蚀性

在过氧化氢空间消毒中,不管是采用哪种工艺,均会对洁净区的某些材料具有一定的腐蚀性,无非是腐蚀速度的快与慢,强与弱的区别罢了。究竟是谁家的好,我们在这里不进行比较,也没有争论的意义,因为造成腐蚀不仅仅是因为工艺或所用过氧化氢浓度的问题,它还包括了用户选择的物品的质量、材料,工艺开发,消毒的频率等等方面的问题,选择了哪家我们就从那家的工艺方面入手去平衡消毒效果与腐蚀问题。

下面是我们对过氧化氢腐蚀的一些建议

1、洁净区的过氧化氢消毒中,我们通常最关心的是对彩钢板的腐蚀。彩钢板的主要结构包括:金属框架、表面涂层、钢板、支撑层以及岩棉等。洁净区彩钢板与彩钢板之间通过中字铝或者其他进行连接,然后缝隙填上密封胶,在进行过氧化氢空间消毒时,过氧化氢主要与彩钢板表面的涂层进行接触。

由于过氧化氢主要与彩钢板的涂层接触,因此涂层的材质、涂层工艺、涂层致密性以及厚度均很重要。市面上有专门用于制药洁净室的抗过氧化氢氧化彩涂板,这种彩钢板的板材部分采用镀锌板,内外表面均进行特殊涂层处理,由于涉及到专利,这里不方便公开。对于表面涂层可采用聚酯、硅性树脂、氟树脂等,耐久性主要取决于板材的镀锌和表面涂层,当然有些表面是贴PVC膜。

彩钢板耐腐蚀不仅仅与板材,涂层材料,涂层工艺有关,还应注意在日常工作中小心不要损坏彩钢板表面涂层。一旦涂层损坏后,过氧化氢就有可能与里面的板材接触,发生化学反应,产生气体与水,使得涂层起泡。

有些彩钢板属于非标定制,可能进行二次加工,比如现场切割,那么需要注意是否表面涂层造成伤害,当然有些优秀供应商会通过图纸排版,在彩钢板厂家加工好发往施工现场。彩钢板通常在制作组装过程会对钢板进行折弯,那么折弯处很容易造成涂层损伤等等。

彩钢板与彩钢板之间的缝隙使用密封胶进行密封,如果密封胶封的不好或者后期有脱落,那么过氧化氢蒸汽有可能进入到彩钢板中从而造成腐蚀。所以这些细节问题都可能会导致在将来造成腐蚀,产生起泡甚至涂层脱落等。

2、应控制消毒过程中过氧化氢的浓度,在过氧化氢空间消毒技术(1)中有介绍,过氧化氢具有腐蚀性,那么在消毒时应在消毒效果和腐蚀性之间做好平衡。过氧化氢浓度高固然能达到很好的消毒效果,但是随之带来的问题就是腐蚀性,所以通过工艺开发,使用最低的浓度达到良好的效果,这也跟设备厂家的技术有很大的关系。成熟的厂家可能一台设备解决问题,而有些厂家对自己的设备不够有信心,同时为了能够卖出设备会推荐用户使用多台设备提高浓度以求通过验证等等。

3、过氧化氢空间消毒的频率,用户应知道过氧化氢对物品具有腐蚀性,那么在制定空间消毒策略上应综合进行考虑,有些用户为了追求效果,每个季度甚至每两个月进行一次空间消毒,如此高的过氧化氢消毒频率很容易造成腐蚀情况的发生。通常定期进行消毒(比如一年1到2次),当环境被异常破坏时使用空间消毒,当环境发现霉菌孢子等使用过氧化氢空间消毒等等。目前采用移动小车的,在消毒阶段结束后,应及时开启强排风。

当然防止过氧化氢的腐蚀还有其他方法,比如使用不锈钢板,但是总体造价会非常昂贵,不适合大面积使用,有钱另说。因个人能力有限,这里可能介绍的不全。

02 过氧化氢消毒的脆弱性

过氧化氢虽然有很好的消毒作用,但是其也有一定的局限性。在这里我们引用英国MHRA(Medicines & Healthcare products Regulatory Agency)的一篇文章说明。VHP (Vapour Hydrogen Peroxide) Fragility,andrewhopkins, Posted on:20 April 2018 - Categories:Compliance matters, Good manufacturing practice,内容如下:
I have been the chairperson for the revision of Annex 1 of the EU and PIC/S GMPS for the manufacture of sterile medicinal products for a couple of years now. As such I engaged with stakeholders and other regulators to understand their wishes and concerns. One particular topic that has come up as a discussion point at a number of the more recent conferences that gives me great concern, and this is around how to sterilise direct and indirect product contact items in an isolator. I therefore felt it was time to go into print regarding the agency’s view.
几年来,我一直担任欧盟和 PIC/S GMP 附录1修订的主编。因此,我与利益相关者和其他监管机构进行了接触,以了解他们的愿望和关切。在最近的一些会议上,有一个特别的话题引起了我的极大关注,那就是如何在隔离器中对直接和间接接触产品的物品进行灭菌。因此,我认为是时候发表一下机构的观点了。

A number of manufacturers are looking at isolator technology in new or existing facilities, which is great to hear, but the fly in the ointment, is that the consideration of how to sterilise direct and indirect contact parts does not always form part of the design process. But before I go further I will clarify what I mean by indirect and direct product contact parts:

许多设备制造商考虑在新的或现有的设备中采用隔离器技术,这是很好的消息,但问题是,如何对直接和间接接触部件进行灭菌的考虑并不总是设计过程的一部分。在进一步说明之前,我想先澄清一下间接和直接接触产品部件的含义:

Indirect product contact parts, as the name implies, are equipment parts that come into contact with items and components, such as stoppers. So, although the equipment itself does not contact the product the items that are “processed” by the equipment do.
Direct contact parts are those that the product passes through, such as filling needles or pumps.
间接接触产品部件,顾名思义,是指与瓶塞等物品和部件接触的设备部件。虽然设备本身不接触产品,但设备 "加工 "产品用到的物品却接触产品。

Direct contact parts are those that the product passes through, such as filling needles or pumps.
直接接触部件是指产品通过的部件,如灌装针或泵。

The issue that is arising is that a number of manufacturers are not including robust systems of sterilisation, such as autoclaves, dry heat or offsite irradiation in their facility designs. This leaves a situation where the Agency is being asked, why Vapour Hydrogen Peroxide (VHP) cannot be used for “sterilisation” of these direct and indirect product contact parts. After all, pharmacopeias refer to VHP as a sterilising agent. However, our concern is that although under ideal conditions, VHP can achieve a reduction of biological Indicator spores of up to 6 logs, the process itself is incredibly fragile.

现在出现的问题是,许多制造商在其设施设计中没有采用高压灭菌器、干热或辐照等强有力的灭菌系统。在这种情况下,监管机构就会问到,为什么不能使用过氧化氢蒸汽(VHP)对这些直接和间接接触产品的部件进行 "灭菌"。毕竟,药典将 VHP 称作灭菌剂。然而,我们担心的是,虽然在理想条件下,VHP 可以减少BI孢子达 6 个对数,但这一过程本身却非常脆弱。


If we cast our minds back a number of years, when VHP was being used to decontaminate the internal surfaces of isolators (not the indirect or direct contact parts) there were a number of issues seen with biological indicators failing the process due to clumping of spores at a microscopic level. This led to a number of papers being written (such as “Biological indicators don’t lie, but in sporicidal gassing disinfection cycles do they sometimes confuse the truth?”, European Journal of Parenteral & Pharmaceutical Sciences 2009; 14(1): 5-10 © 2009 Pharmaceutical and Healthcare Sciences Society) that justified biological indicator failure at one or two locations based on statistical analysis. The papers also recommended that a number of indicators (usually 3) be placed at each location to demonstrate a 3 log reduction (which is not a sterilisation process). This, along with other evidence, such as VHP failure due to very minor occlusion, even to the degree that fatty acids from a fingerprint may “protect” contaminating organisms from the VHP demonstrate the true fragility of the process as a sterilant.

回想几年前,在使用 VHP 对隔离器的内表面(而非间接或直接接触部分)进行消毒时,曾出现过一些问题,即由于孢子在微观层面上结块,导致生物指标无法通过消毒过程。为此,我们撰写了多篇论文(如 "生物指示剂不会说谎,但在杀菌气消毒循环中,它们有时会混淆事实吗?2009;214(1)5-10 © 2009 制药与保健科学学会),根据统计分析证明BI在一个或两个位置失效是合理的。这些论文还建议在每个位置放置一定数量的BI(通常为 3 个),以显示 3-log 的降低(这不是灭菌过程)。这一点以及其他证据,如 VHP 因极小的阻碍而失效,甚至指纹中的脂肪酸可能会 "保护 "污染生物免受 VHP 的污染,都表明了该工艺作为灭菌剂的真正脆弱性。


If we then consider the design of some of the indirect and direct product contact parts, we find that a number of them are either difficult to achieve VHP penetration, or, damage and wear and tear can leave surfaces that lead to difficulty to clean and therefore potential occlusion.

如果我们再考虑一些间接和直接与产品接触部件的设计,就会发现其中一些部件很难实现 VHP 的渗透,或者由于损坏和磨损而导致表面难以清洁,从而产生潜在的阻碍,影响VHP与部件表面接触。


VHP, when well controlled and validated, is a useful method for the decontamination of the surrounding workspace, e.g. an isolator environment. However, given the above concerns, our current stance is that VHP cannot be used to sterilise critical items. Even if some of the concerns can be removed by well thought out processes, this still leaves the sterilisation at risk of the vagaries of manual process during set up. For instance, how many of us see ‘human error’ as a high percentage of root cause errors during deviation investigations? Therefore, it would be a high risk option and potentially leave the patient at risk from such a fragile process.

如果控制得当并经过验证,VHP 是净化周围工作空间(如隔离器环境)的一种有用方法。不过,鉴于上述顾虑,我们目前的立场是,VHP 不能用于关键物品的消毒。即使可以通过深思熟虑的流程消除一些顾虑,但这仍然会使灭菌工作面临人为错误引起的风险。例如,在偏差调查中,有多少人认为 "人为错误 "是造成错误的高比例根源?因此,这将是一个高风险的选择,并有可能使病人受到这种脆弱工艺的威胁。


So, what are we expecting?

那么,我们的期望是什么?


Our expectation is that the contact parts (direct and indirect) are sterilised using a robust sterilisation method that meets the current requirements of annex 1. This means that:

我们希望接触部分(直接和间接)采用符合EU GMP 附录 1 现行要求的可靠灭菌方法进行灭菌。这意味着:


the sterilising agent reaches all of the critical surfaces in a consistent and repeatable manner, typically requiring processes such as moist or dry heat sterilisation.
灭菌剂以一致和可重复的方式到达所有关键表面,通常需要采用湿热或干热灭菌等工艺。

the item is unloaded from the sterilisation process either wrapped in integral covering or container, or is transferred under grade A conditions, such as a transfer isolator into the manufacturing isolator.

物品从灭菌过程中卸下时,要么用整体覆盖物或容器包裹,要么在 A 级条件下转移,如将转移隔离器转移到生产隔离器中。


We also expect that the parts are not exposed to the isolator environment until the isolator has been closed and after completion of the work zone decontamination VHP cycle.

我们还希望,在隔离器关闭并完成工作区净化 VHP 循环之前,部件不会暴露在隔离器环境中。


We continue to move increasingly into a pharmaceutical world governed by the principles of quality risk management. We are unable to say that VHP will never be an acceptable approach. However, manufacturers who are considering a different approach to sterilisation, or to any other GMP requirement, seek a dialogue with the agency at an early stage. This may save on costly modification later on in the project and who knows, you may even receive some useful help! 

我们将继续越来越多地进入一个受质量风险管理原则支配的制药世界。我们不能说 VHP 永远不会成为一种可接受的方法。但是,正在考虑采用不同方法进行灭菌或满足任何其他 GMP 要求的制造商,应在早期阶段寻求与有关机构进行对话。这可能会节省项目后期的改造成本,谁知道呢,你甚至可能会得到一些有用的帮助!


原文链接:https://mhrainspectorate.blog.gov.uk/2018/04/20/vhp-vapour-hydrogen-peroxide-fragility/


通过以上的内容可以看出国际上监管机构对VHP用于灭菌的担心,所以也从侧面更加说明,过氧化氢空间消毒技术的脆弱性。同时也说明了,我们在使用过氧化氢进行空间消毒时应尽可能的消除对过氧化氢产生影响的因素,否则很容易导致消毒失败。