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  • Panicking!!!

    So I can see that this has come up before and have tried searching previous posts but no luck
    It is about the 'Sodium Chloride 0.9% in 500mls and 0.45%in 500mls)

    So there is a space on my work sheet for ' formulations and calculations '

    So I have - 0.9/100x500 = 4.5g sodium chloride to make up 500ml of a 0.9% solution.

    And then I have - 0.45/100x500= 2.25g sodium chloride to make up 500ml of 0.45%

    Is this enough for both the Formulation and calculation - ? If not any advice etc would be much appreciated!
    I have not done the displacement value as I have found that answer on previous forum questions that it is not needed.

    Thank you


  • #2
    Displacement values are used when you have to mix a solid in a solid to make it fit in a given volume.
    47 BC : Julius Cesar : Veni Vidi Vici : I came, I saw I conquered.
    2018 AD : Modern Man : I shopped, I clicked, I collected.
    How times change.

    If you find you have read something that has upset or offended you an anyway please unread it at once.

    Comment


    • 1986marie
      1986marie commented
      Editing a comment
      Thank you I did read that it was more of as solid - solid and for suppositories.

      Do you have any advice on the other topic about formulation and calculations ?

  • #3
    Have you used the search box to search the forum?
    johnep

    Comment


    • 1986marie
      1986marie commented
      Editing a comment
      yes, I have, but could not find a answer - or maybe I was not looking for the right thing ?

  • #4
    Did you search on sodium chloride?
    johnep

    Comment


    • 1986marie
      1986marie commented
      Editing a comment
      Yes, That's when I saw that you said it had already been answered, so I went back through the pages and clicked on all the links and read them (the ones that are highlighted)
      I could see the same problem for others, I could see my workings out were fine and I read about displacement which was very helpful. But I just could not see if anything else I was missing. Either from the formula or calculations.

  • #5
    The pharmaceutical press do some work books for calculations.
    Although they miss some steps in places.
    Worth a look if you can find them in the Library if you are in Uni.
    Or a couple of students can club together and get a copy to share.

    There are some youtube presentations too.

    Apparently you need to wear a white coat to do these calculations. <g>
    47 BC : Julius Cesar : Veni Vidi Vici : I came, I saw I conquered.
    2018 AD : Modern Man : I shopped, I clicked, I collected.
    How times change.

    If you find you have read something that has upset or offended you an anyway please unread it at once.

    Comment


    • #6
      OK. I have just made an eye lotion containing 9grm/litre (normal Saline).
      I used 9 grm (weighed on the kitchen scales) and dissolved in 1,000 mls water. (I actually used carbonated spring water ex Sainsburys). Carbonated water is acidic due to the CO2 and is very low in bugs. Soln brought to boiling to remove CO2 and sterilise. (Boiling with a solute to raise BP and boiling with a bactericide)
      So, 500ml would contain half this quantity, ie 4.5grm. Displacement values can be disregarded for this low concentration. Calculation is done by simple proportion.
      Ie !000 ml contains 9 grm of NaCl. therefore 500 ml contains 4.5 grm of NaCl. 500ml of 1/2 strength NS would contain 2.25 grm.
      Vast majority of pharmaceutical calculations are simple proportion or percentages.
      You should be thoroughly conversant with these.
      To get practice, Really need to do a calculation each day
      johnep

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