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Saturday 21 February 2015

Why 70% Isopropyl alcohol is used as disinfectant in pharmaceutical industries?

Iso-propyl alcohol (IPA) is widely used as a disinfectant in pharmaceutical companies . IPA is very effective on gram positive as well as gram negative bacteria. Most of the hand disinfectants available in the market contains IPA as an active component just because of its effectiveness. IPA is very effective and kill microbial cell with in a few seconds. But one limitation of IPA is that it is not effective against bacterial and fungal spores. Disinfectant efficacy depends upon two factors. First is concentration of disinfectant solution and second is contact time. Disinfectant validation activity also depends upon these two factors. In pharmaceuticals that's why validation activity must be performed to validate its effective concentration and contact time. Different guidelines and pharmacopoeias recommend 70% IPA solution because at this particular concentration, IPA is very effective. But why 70% IPA is effective and recommended by pharmacopoeias and guidelines why not 100 %? The reason is behind the mode of action of 70% IPA. Bacterial cells have proteins in their cell wall and when this protein comes in contact with the 70% IPA during disinfectant application, coagulation of proteins takes places in which denaturation of proteins occurred and after that IPA penetrate in the interior of the cell which cause lysis or death of the cell. Protein coagulation also happens in case of 100% IPA but with very fast rate and because of this very fast protein coagulation process denatured protein forms protective layer out side of the cell. When this happens, 100% can not penetrate inside the cell and not able to kill the microbe. Microorganisms become dormant in that conditions. In case of 70% IPA protein coagulation takes place with a slow rate and due to this 70% IPA get enough time to penetrate in the cell and kill the microorganism. Another factor is contact time, 70% IPA takes longer time to evaporate from any surface hence get enough contact time and in this mean time it show its efficacy but in case of 100% IPA, evaporation will be very fast, contact time will be less and it will not be so effective against microbes. That's why 70% IPA solution is used as disinfectant in pharmaceuticals industries.

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19 comments:

  1. Quality Excipients22 July 2015 at 04:53

    Nice article. Actually alcohol is widely used in pharmaceutical industry. Pharma grade alcohol i.e. Ethanol or Ethyl alcohol is used as solvents in medicine formulation.

    ReplyDelete
    Replies
    1. Sandeep Dhiman26 July 2015 at 08:20

      Thanks Quality Excipients for your valuable comment.

      Delete
  2. Unknown31 March 2016 at 22:41

    Great answer. I have a query still.. Why 70% specifically and why not 75%, 80% or 85%. I understand contact time is key, still, does 70% carry any other significance?

    I have been having this question in my mind for a long time. Felt this forum is apt to throw this for discussion.

    Thanks

    ReplyDelete
    Replies
    1. Anonymous27 April 2016 at 08:34

      I think the last sentence answers your question. 70% strikes the right balance of contact time and efficacy.

      Delete
    2. Sandeep Dhiman4 September 2016 at 11:17

      Vijay Raghvan, in disinfectant validation acceptance criteria is 3 log reduction for vegetative cells.I am not denying, 75%, 80% and 85% IPA also kills microorganisms but we have to select the least effective concentration of disinfectant (which gives 3 log reduction minimum) in minimum contact time. If 70% IPA is able to provide 3 log reduction in few seconds (as per validation study) for vegetative cells then there is no need to increase the concentration.As the concentration of IPA increases its effectiveness decreases as i have mentioned above and cost factor is also there if you use high concentration.

      Thanks and enjoy the blogs...

      Delete
    3. Anonymous26 August 2020 at 15:39

      Also, I think at approximately 70% concentration, IPA and water form an azeotrope. This means the concentration of IPA in water does not change with evaporation.

      Delete
  3. Unknown9 June 2016 at 13:17

    What is the expiry of 70% IPA?

    ReplyDelete
  4. Unknown9 June 2016 at 13:17

    This comment has been removed by the author.

    ReplyDelete
  5. Unknown9 June 2016 at 13:18

    What is the expiry of 70% IPA?

    ReplyDelete
    Replies
    1. Sandeep Dhiman4 September 2016 at 11:32

      Zaynab Shabbir, expiry of 70% IPA depends upon your validation study.you can do hold time study of 70% IPA for 0 hour, 24 hours, 48 hours, 72 hours and 96 hours. You have to validate, after holding 70% IPA whether it will give 3 log reduction for vegetative cells or not and one more concern is there if you use 70% IPA for grade A then you have to also ensure the sterility of 70% IPA after hold time

      Thanks...

      Delete
  6. Unknown15 April 2017 at 01:59

    70 % IPA is more effective its a validated study, if you are interested in 80% OR any other concentration it need study for the same in compression to 70% by disinfectant efficacy test method.

    Thanks
    Dheerendra

    ReplyDelete
  7. Sandeep Dhiman10 August 2017 at 04:46

    This comment has been removed by the author.

    ReplyDelete
  8. Sandeep Dhiman10 August 2017 at 05:14

    Dear Azad Suraniya, Dey Engley agar neutralizes a broad spectrum antiseptic and disinfectants including quaternary ammonium compounds, phenolics, iodine and chlorine preparations, mercurials, formeldehyde and gluteraldehyde. Sodium bisulphite neutralizes aldehyde, sodium thioglycollate neutralizes mercurials, sodium thiosulphate neutralizes iodine and chlorine, lecithin neutralizes quaternary ammonium compounds and polysorbate 80 neutralizes substituted phenolics. That's why Dey Engley agar media is recommended for disinfectant validation, surface monitoring and other testing which includes disinfectants.

    ReplyDelete
  9. Unknown1 October 2017 at 23:44

    can u plz provide protocol or sop for 70 % ipa validation?

    ReplyDelete
  10. vikas singh9 October 2017 at 04:42

    Hello Sir,

    I'm big fan of you.

    Sir can you tell me, how much time take for 3 log Reduction and also how much inoculum killed in that time ?

    ReplyDelete
  11. Sandeep Dhiman2 November 2017 at 11:21

    Vikas singh, it depends upon your validation study. Don't just go with the article. Articles are just for references, just perform your validation study and validate the concentration and contact time.

    Thanks

    ReplyDelete
  12. Vipin2 June 2018 at 02:39

    Dear Sandeep ji, Is it mention any where that there should be 3 log reduction in disinfectant validation and their contact time...please tell me the reference.

    ReplyDelete
  13. bloomChemAG5 May 2022 at 02:10

    Thanks for sharing these useful information! This is really interesting information for me. Isopropyl alcohol(IPA) is an isomer of propyl alcohol with antibacterial properties. Although the exact mechanism of isopropanol's disinfecting action is not known, it might kill cells by denaturing cell proteins and DNA, interfering with cellular metabolism, and dissolving cell lipo-protein membranes.

    ReplyDelete
  14. Chemstock22 August 2022 at 06:40

    Nice Post.
    Isopropyl Alcohol
    Ethanol
    Ethyl Alcohol

    ReplyDelete