Hi Gabyher,
Since I'd been thinking about how dilute CDH could be administered with an insulin pump lately anyway, I decided to sort of simulate that using a 3/4 inch 27g butterfly needle. Below is a pic of what that looked like in my abdomen area. I was able to inject the entire 10cc of 50ppm slowly (over about 10 to 15 minutes, with only slight discomfort. It did form a little bit of a bump so I decided to walk around and flex my stomach muscles to encourage the circulation of it into my system while I pushed the last 5ml or so in, and that did the trick - the bump reduced quite nicely.
I used reverse osmosis drinking water to make my CDH and it's also what I used to dilute it to 50ppm. It would be better though if I could have diluted it with saline solution and so that's what I will try to do next time and it's what I would recommend to anyone. Also, the water I used was quite acidic, about 5.5 pH, and so I wouldn't want to use it for intramuscular, but it worked okay, with just a little burn for subcutaneous use.
Below are a couple of pictures I took. The picture with the black circle was taken 12 hours after the injection. I circled the area of the injection so I could examine the injection site later to see if there was any redness or bruising which would indicate that the solution caused some sort of tissue damage. I'm happy to say that there only appears to be a very slight amount of redness which is barely noticeable, and the area is only slightly tender to touch.
Hope this helps,
Scott McRae
PS. If I needed to fight some kind of disease, I would probably do this 2 to 3 times a day but I would definitely try to use saline solution if I could. A saline solution would also help to get the pH closer to 7 which should help reduce the slight burning I felt.