ophthalamic

Question 1

USP definition of ophthalmic preparation

Answer 1

free from particles, suitably compounded and packaged for installation in the eye

Question 2

what section of USP has sterile preparations

Answer 2

USP 797

Question 3

what is the purpose of ophthalmic preparations

Answer 3

admin medication to the eye
lubrication
cleansing

Question 4

are ophthalmic products local or systemic

Answer 4

usually local, systemic is rare and includes GI coupling and epithelial absorption

Question 5

what is the capacity of the eye

in drops and mg

Answer 5

1 gtt/eye

50mg/eye

Question 6

how do you administer eye meds

liquid vs semi-solid

Answer 6

liquid–> use 1-2 drops

semi-solid –> 1/4 - 1/2

Question 7

are ophthalmic preparations used in cleansing and lubrication

Answer 7

Yes

Question 8

ophthalmic dosage forms

Answer 8

solutions (aqueous)
ointments (white petro and min oil)
suspensions (prednisolone)
gels (timolol) or gel upon administration

Question 9

ideal pH for ophthalmic

tolerable range

Answer 9

7.4

tolerable range is 6.5-8.5

Question 10

ideal tonicity

Answer 10

277millimolar

Question 11

tonicity definition

Answer 11

a measure of concentration. moles of solute particles per L of solution

Question 12

mole

Answer 12

6.022 x 10 23

Question 13

what colligative properties are dictated by tonicity

all depend on ____________

Answer 13

osmotic pressure
freezing point depression
boiling point elevation
vapor pressure
 *only depend on number of particles in solution, not size

Question 14

freezing point vs freezing point depression

Answer 14

FP is the temp at which a liquid freezes

FPD is the number of centigrade degrees below freezing point of water (0 C) at which a liquid freezes

Question 15

for water, freezing point is depressed ____ centigrade for every ____ of particles per _______ of solution

Answer 15

1.86
mole
liter

Question 16

when given g solute /mL, how do we calculate the FPD?

Answer 16

given g/mL
convert g to mole
convert mL to L
mole x 1.86

Question 17

freezing point depression is (-7.23 degrees centigrade or 7.23 degrees centigrade) while freezing point is (“ “ “)

Answer 17

FPD is 7.23 while freezing point is -7.23

Question 18

what is physiologic tonicity

Answer 18

277mM

Question 19

tolerable tonicity range

Answer 19

200-600

Question 20

I value definition

Answer 20

dissociation factor

1 mole solute generates ! number of particles

Question 21

I value for 
non-electrolytes
2 ion electrolytes
3 ion
4 ion
5 ion

Answer 21

1. 0
2. 8
3. 6
4. 4
5. 2

Question 22

zinc sulfate unique I value

Answer 22

1.4

Question 23

SCE value definition

Answer 23

a value that when multiplied by the g or mg of a substance will give the sodium chloride equivalent that it contributes to a products total tonicity

Question 24

SCE method considerations

Answer 24

used when pH is NOT an issue

Question 25

Theorem A

Answer 25

if you add an isotonic solution of any volume to a second isotonic solution of any volume the resulting solution will also be isotonic

Question 26

what are V values

Answer 26

mL of H2O required for dissolution of 300mg of drug which results in isotonic solution

Question 27

assumptions involved in v values

Answer 27

contribution of solute to the overall soln volume is negligible and that concentration is 300mg/V-value (mL)

Question 28

USP method

Answer 28

used when pH is not an issue
prepare an excess amount of isotonic NaCl, calculate volume of each solution required, which when combined will yield the desired concentration of drug. qs to final volume

Question 29

Sorensen Method

Answer 29

used when pH is an issue
prepare excess buffer stock solution of appropriate proportion to yield desired pH in final product

from table get % of buffer components and 9/100mL for total tonicity.
total - part (SCE) = amount NaCl needed
dissolve to a final volume with buffered stock solution