QUESTION ON ADJUSTMENT OF ISOTONOCITY BY SODIUM CHLORIDE
EQUIVALENT METHOD
For i values, E values and molecular weight refer to the tables below.
1. How many grams of dextrose should be used in compounding the prescription below?
(Answer 1.59g)
RX
Ephedrine hydrochloride 0.5
Chlorobutanol 0.25
Dextrose q.s
Rose water ad 50.0ml
Make solution isotonic
Sig. Nose drops
Sodium chloride equivalents are as follows
Ephedrine HCL = 0.30
Chlorombutol = 0.18
Dextrose = 0.16
2. Find the quantity of boric acid (in grams) to be used in compounding the following
prescription. (answer 0.471)
Rx
Tetracaine hydrochloride 0.1
Zinc sulphate 0.05
Boric acid q.s
Purified water ad 30.0
Make isotonic solution
Sig. in eyes
Sodium chloride equivalents are as follows
Tetracaine HCl = 0.18
Zinc sulphate = 0.15
Boric acid = 0.52
3. Calculate the dissociation factor of pilocarpine hydrochloride dissociating 80% (2 ions)
in a certain concentration. Assume there 100 particles before dissociation.
4. Papaverine hydrochloride (m.w 376) is a 2-ion electrolyte, dissociating 80% in a given
concentration. Calculate its sodium chloride equivalent.
5. Calculate the E values of the following aqueous solutions at 1% concentration.
a) Chlorobutanol
b) Tetracaine hydrochloride
c) Ephedrine sulfate
6. How many grams of sodium chloride should be used in compounding the prescription?
Rx
Procaine Hydrochloride 1%
Sodium chloride q.s
Sterile water for injection ad 100
Make isotonic sol.
Sig for injection
7. How many grams of sodium chloride should be used in compounding the prescription?
Rx
Cocaine hydrochloride 0.6
Eucatropine hydrochloride 0.6
Chlorobutanol 0.1
Sodium chloride q.s
Purified water ad 30.0
Make isotonic sol.
Sig for the eye
8. How many grams of boric acid should be used in in compounding the prescription?
Rx
Zinc sulphate 0.06
Boric acid q.s
Purified water ad 30.0
Make isotonic sol.
Sig. Drop in eyes
9. How many milliliters of a 0.9% solution of sodium chloride should be used in
compounding the prescription?
Rx
Phenylepinephrine hydrochloride 1.0
Chlorobutanol 0.5
Sodium chloride q.s
Purified water ad 100.0
Make isoton. sol.
Sig. Use as directed
10. How many grams of sodium chloride should be used in preparing the solution?
Dextrose, monohydrate 2.0%
Sodium chloride q.s
Sterile water for injection ad 1000ml
Label; Isotonic Dextrose and Saline solution
11. How many milliliters of a 5% solution of boric acid should be used in compounding the
prescription?
Rx
Oxymetazoline hydrochloride 2%
Boric acid solution q.s
Purified water ad 15.0
Make isotonic sol
Sig. For the nose as decongestant
12. How many grams of dextrose monohydrate should be used in preparing a liter of a 0.5%
isotonic ephedrine sulphate nasal spray?
13. How many grams of boric acid should be used in compounding the prescription?
Rx
Tetracaine Hydrochloride 1.0
Boric acid q.s
Purified water ad 30.0
Make isoton sol.
Sig. Eye drops
14. How many grams of potassium nitrate could be used to make the following prescriptions
isotonic?
Rx Sol. Silver Nitrate 60
1:500 w/v
Make isoton. Sol.
Sig. For eye use
QUESTIONS ON ADJUSTMENT OF ISOTONICITY BY FREEZING POINT DEPRESSION
METHOD
15. Render the following solution iso osmotic with blood and tears
Dextrose, anhydrous 2.5%
Sodium chloride q.s
Sterile water for injection ad 1000ml
(Answer 0.512%)
Freezing point of 1% dextrose is 0.09C
b) How many grams of sodium chloride should be used in preparing the solution?
( Answer 5.12g)
16. Rx Ephedrine hydrochloride 0.15g
Chlorobutanol 0.15g
Sodium chloride q.s
Rose water ad 10ml
How many grams of sodium chloride should be used in compounding the prescription?
The freezing point of 1% Ephedrine hydrochloride is 0.165 and that of 1%
chlorobutamol is 0.14. (Answer 0.044g)
