3You have on hand 17 grams of a 1 ww HC ointment formulation

3.You have on hand 17 grams of a 1% (^w/_w) HC ointment formulation but need to dispense a 2.5 % (^w/_w) HC ointment. If you combine the 17 grams of 1% (^w/_w) ointment with a 5% (^w/_w) ointment what total weight of 2.5% (^w/_w) ointment can you prepare?

A. 10.2 g B. 27.2 g C. 28.3 g D. 45.3 g

4.

The following prescription comes into your pharmacy for a 15 kilogram pediatric patient:
R_x: Tolmetin Na 20 mg/kg/day in 4 divided doses
Lactose qs
M.ft. cap #8 size 3

Sig: 1 cap q.i.d.

Tolmetin is available 400 mg strength capsules (total content weight = 550 mg). How many milligrams of capsule powder should be weighed out to provide the required amount of tolmetin to compound the order?

A. 75mg B. 400mg C. 600mg D. 825mg E. 900mg

5.

The following prescription comes into your pharmacy for a 44 pound patient:
R_x: Phenobarbital 1mg/kg
     Lactose qs
     M.ft. caps #8

Phenobarbital is available to you as 15 mg tablets (average tablet weight = 80 mg). In order to compound this product you need to crush _________ tablets and weight out __________mg of the crushed powder. Enter your values as whole numbers only with no units.

Solution

3.

let weight of 5% w/w ointment is x

for the combination to be 2.5% w/w, we get

(.17 + .o5x)/(17+x)=.025

after calculations

x=10.2

total weight =17 +10.2=27.2 (B)

4.

1 capsule dose contain 20*15/4 mg tolmetin =75mg

for 8 doses of capsule tolmetin=75*8=600mg

for 400 mg we have 550 mg total content

for 600 mg we need=550/400*600=825mg (D)

5.

44pound=19.96kg

for 1 dose phenobarbitol=19.96mg

for 8 dosesn phenobarbitol=19.96*8=159.68mg which is equal to 160 mg

for 15 mg we need 80 mg tablet weight

for 160 mg we need =80*160/15=853.33 which is equal to 853mg

number of tablets=160/15=10.66=11 tablets

answer 11 and 853