Great video. It has helped me a lot but I need help with this question: The pharmacist receives an order for 10 ml tobramycine 1% ophthalmic solution. She has tobramycion 40mg/ml solution. Tobramycin does not dissociate and has a MW of 468. Find the E value for tobramycin and determine how many milligrams of NaCl are needed to make the solution isotonic. Round to 2 decimal places. I was able to calculate the E value and I had 0.069 but then I got stuck.
Rx Oxytetracycline HCl 1/2% Tetracaine HCl Sol. 2% 15 mL NaCl qs Pur. Water ad 60 mL Make isotonic sol. Sig. For the eye. The 2% solution of Tetracaine HCl is already isotonic. How many mL of a 0.9% isotonic solution of NaCl should be used in compounding the prescription? hope you could help me
Thank you Kyla for watching and for the comment. Your question has been solved in this video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-cmcXe8Injmk.html .
Rx proclacline HCL 1% Benzallonia 1:1000 Purified water 50 ml Make isotonic solution. How many ml of normal saline should be used in compounding the above prescription? Ev=0.21 EV=0.16.
its extremely helpful .thanks a lot prof. just one thing I want to ask how we can relate freezing point to tonicity how to solve the calculations in which we are ask to find freezing point of molal solution of any substance say sodium chloride.
You are right Agusta. Step 2 is where all the action is and may be confusing. One way to process to make it less complicated is to recall that in step 2 you always want to multiply the quantity of the ingredient in grams by the E value to get the equivalent of the NaCl. Keep up the good work.
Thank you, mx for watching and for the comment. You can typically find the e-value in table. You can also calculate the E-value using this formula. E= ((molecular weight of NaCl/ i factor of NaCl) * (i factor of the substance/ molecular weight of substance)). Hope this helps.
Thank you Simweeleba for watching and for the comment. The 0.9% is the percentage concentration of normal saline solution (sodium chloride solution) which is isotonic. Hope this helps.
