How many grams of NaCl are needed for preparation of 97 mL o

How many grams of NaCl are needed for preparation of 97 mL of a 1.2 % w/v isotonic solution of procaine hydrochloride (E = 0. 21)? Use the Sodium Chloride Equivalent (E value) method. Enter your result with 3 decimal places and no units.

Solution

Sodium Chloride Equivalent Method

Step1: E * (amount of drug in solution) = X

Step2: (0.9g/100mL) * (volume of solution in mL) = Y

Step3: Y–X = amount of NaClneeded

97 ml of 1.2 % w/v solution of drug(E=0.21), How much NaCl?

To render the solution isotonic.

S1: 0.21 * 97*1.2/100 = 0.24444g

S2: (0.9g/100mL) * (97mL) = 0.873g

S3: 0.873-0.2444=0.62856 g

hence 0.629