Suppository calculation

Suppository Calculation Practice Problems

Q1: Prepare a suppository containing 200 mg of the active drug with a density of 3.0. The base has a density of 1.0. The weight of the blank base using the same mold is 2.0 g. How many grams of the base is required?

Step 1: Find out the volume of the drug

v(drug)= m(drug)/density(drug)

           =0.2 g/3.0g/mL

           =0.067 mL

Step 2: Find out the replace volume, which is equal to the volume of the drug

v(base replaced)= v(drug)=0.067 mL.

Step 3: find out the replaced amount

     m(base replaced)=v(based replaced)x density (base)

                              =0.067 ml x 1.0 g/mL

                              =0.067 gram

Step 4: Find out the required base 

  Base required = estimated amount-replaced amount

                       =2.0 - 0.067 g

                       =1.933 gram

Q2: How many grams of base is required to prepare a suppository containing 150 mg of drug x with a density of 1.8 g/mL? The density of the based is 1.5 g/mL. The weight of the blank suppository is 2.0 g

Step 1, Find out the volume of the drug

 V(drug)=m(drug)/density (drug)=0.15 g/1.8 g/mL=0.083 mL

Step 2. find out the replaced volume of the base

 V(base replaced)=V(drug)=0.083 mL

Step 3. Find out the weight of the replace drug 

 m(replaced base)=v(replaced base)xdensity (drug)=0.083*1.5 g/mL=0.125 g

Step 4.Find out the weight of the required base

m (required base)=m(estimated base)-m(replaced base)=2-0.125=1.875 g

Q3: Prepare 12 suppositories, each containing 250 mg of the active drug with a density of 1.8. The base has a density of 0.9. The weight of the blank base using the same mold is 2.0 g. What is the total volume of the drug?

calculate the volume using the equation Density(p)=Mess (m)/volume (v)

V=mess/density=0.25*12 (total weight of the drug)/1.8 (density of the drug)=0.139*12=1.668 mL

Q4: In Q3, what is the base replacement volume?

Base replacement volume=drug volume=1.668 mL

Q5: in Q3, what is the base replaced weight and how many grams of the base is required?

Replaced weight=replaced volume* density of the base=1.668 mL* 0.9 g/mL=1.501 g

Total base required= Total estimated-replaced weight=2 * 12 -1.501=22.49 g

Q6: Prepare a suppository containing 150 mg of the active drug with a density of 2.0. The base has a density of 1.5. The weight of the blank base using the same mold is 2.0 g. How many grams of the base is required?

Step 1, Find out the volume of the drug

 

Step 2. find out the replaced volume of the base

 V(base replaced)=V(drug)

Step 3. Find out the weight of the replace drug 

 m(replaced base)=v(replaced base)xdensity (drug)

Step 4.Find out the weight of the required base

m (required base)=m(estimated base)-m(replaced base)

Q7: How many grams of base is required to prepare a suppository containing 0.10 g of morphine with a density of 1.5 g/mL? The density of the based is 2.0 g/mL. The weight of the blank suppository is 3.0 g

Step 1, Find out the volume of the drug

 

Step 2. find out the replaced volume of the base

 V(base replaced)=V(drug)

Step 3. Find out the weight of the replace drug 

 m(replaced base)=v(replaced base)xdensity (drug)

Step 4.Find out the weight of the required base

m (required base)=m(estimated base)-m(replaced base)

Q8: Prepare a suppository containing 2.5 % of phenobarbital using cocoa butter as the base. The weight of the pure cocoa butter suppository is 2.0 g. The weight of each suppository is 1.95 g. What is the replacement factor?

F=1+((E-G))/(G×x)×100

   =1+(2-1.95)/(1.95*2.5) * 100

   = 1+ 5/4.875 =2.026

Q9: In Q8. How many base are required to prepare 12 suppository?

Q11: Your colleague prepared some rectal suppositories using metal suppository models. The volume of the models is 2.0 mL.

Your colleague prepared a dozen rectal suppositories using a metal suppository mold. The volume of the mold is 2.0 mL. When he filled the mold with pure drug x, the weight of the drug was 2.0 grams. When he filled the mold with the pure base, the weight of the base is 2.2 grams, however, he accidentally read this 2.2 grams as 2.4 grams and made the calculation using this incorrect number. To prepare a dozen suppositories, how many grams of the base did he waste theoretically? (Assuming each suppository contains 100 mg of drug x)

Average particle size calculation

Medication powder average particle size calculation

Q1: what is the average particle size of the following powder

size of particles (um)    Numbers in the group 

20-40                                      25    

40-60                                      68 

60-80                                      80

80-100                                    110

100-120                                  152

120-140                                  85 

Q2: A lactose bulk powder was past through 5 sieves and the retained weights were obtained. What is the average particle size for this bulk powder?

Sieve #    Weight retained (g)    Opening (mm)

#6                     20.5                  3.36   

#8                     42.3                  2.38

#10                    68.8                 2.00  

#12                    21.0                 1.68

#14                    5.1                   1.41

#16                    1.5                   1.19

Concentration calculation

Q1: A medical powder is dissolved in water and then diluted into 100 mL to be dispensed to a patient. The concentration of this drug in the final solution is 110 mg every 5 mL. How many grams of this powder was used in total?

x gams/ 100 mL = 0.11 g/ 5 mL

x=0.11/5*100

Q2: What is the concentration strength in mg/mL when 325 mg of drug X is dissolved in water to make a 500 mL of solution?

x g/100 mL= 0.325 g/ 500 mL

x=0.325/500*100

Q3: A pharmacist needs to add 500 mg of calcium gluconate to a fluid. The pharmacist has a 10% (w/v) calcium gluconate stock solution. How many milliliters of this stock solution is required?

10% is 10 grams in 100 mL. 

500 mg=0.5 g

10g/100 mL=0.5 g/x mL

x=0.5 * 100/10

Q4: A pharmacist needs 1.95 g of a salt for a prescription. How many milliliters of a 32.5% stock solution of the salt are needed?

32.5% is 32.5 grams in 100 mL

32.5 g/100 mL = 1.95 g/ x mL

x=1.95 * 100/32.5

Dosage calculation problems

Q1: Penicillin V suspension 240 mL (200,000 units/tsp). Sig: 400,000 unit tid.  How many days will this prescription last the patient?

Answer:

1 tsp=4.93 mL

200,000 unit/tsp=200,000 unit/4.93 mL

240 mL=240/4.93=48.68 tsp

48.68 tsp*200,000 unit/tsp=9,736,308.32 unit

9,736,308.32/400,000=24 doses

24/3=8 days

Q2: A prescription calls 1.2 mL of saline as one of its ingredients. A dropper was calibrated and found to deliver 3 mL of saline 10 drops. How many drops is needed to prepare this prescription?

Answer:

Q3: Irinotecan is administered through i.v. infusion at 5 mg/kg in a 21-day cycle. For a patient weighing 70.0 kg, how many mg of irinotecan is required in 3 months?

Answer:

5*70*3=1,050 mg

Q4: In a PK study, A patient took acetaminophen 500 mg. A nurse collected 325 uL of serum from the patient and took 10 uL for dilution to afford a 250 uL solution. The concentration is 4 ug/mL after dilution. What is the concentration in serum?

Answer:

 

Q5: The dose of lucanthone hydrochloride is 5 mg/kg body weight three times a day for 1 week. What should the total daily dose (in grams) be for a patient weighing 120 lb

Answer:

Step 1: Convert lb to kg

Step 2: find out the amount of each dose by multiplying  5 mg/kg*body weight in kg

Step 3: Total dose= 3*7*amount of each dose

Q6: Irinotecan is administered through i.v. infusion at 5 mg/kg in one cycle. For a patient with 165 lb, how many mg of irinotecan is required for 6 cycles

Q7: The dose of drug X is 180 mg/m2, how many milligrams of this drug should be administered to a patients weighing 75 kg with 175 cm height?

Q8: A child weighing 28 lb has a urinary tract infection. The physician ordered the following medication. The pharmacist has on hand streptomycin sulfate injection 1 g/2.5 mL. How many milliliter should be administered every dose?

Rx: Streptomycin sulfate, 20 mg/kg/day

          Sig: q12h, im. Seven days

Q9: A child weighing 80 lb with pneumonia was prescribed Tao 7.5 mg/kg every 6 hours for 5 days? Tao is available only as 250 mg capsules. How many grams will this patients receive per day? How many 250 mg capsules would be needed for this order?

Q10: A child weighing 30 lb needs a drug in a dose of 5 mg/kg. How many milliliters of a pediatric suspension of the drug, containing 20 mg/mL, should the patient receive?

GPA calculator

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