Compounding Lectures 4-10 Review

Question 1

For emulsions, do they require preservatives (like if its o/w, w/o)?

Answer 1

Yes – b/c they have water (even if it’s a small amount)

Question 2

What are the diff classes of emulsifying agents?

Answer 2

• May stabilize an emulsion through use of surfacants, hydrocolloids or solid particles
  o Surfacants:
   Anionic (sodium docusate, sodium oleate) or non-ionic (Spans & Tweens)
   Catonic (ex: quaternary ammonium halides)
  o Hydrocolloids:
   Natural (gelatin), semi-synthetic (methylcellulose) or synthetic (Carbopol)
  o Solid Particles:
   Bentonite, Aluminum hydroxide, Mg trisilicate

Question 3

What are the 4 categories of preparing an emulsion?

Answer 3

1. Continental:
   - Acacia + Oil (Levigation), then add ALL WATER at once
2. English:
   - Acacia + Water (Titurated), then add OIL IN PORTIONS
3. Bottle
   - Acacia in bottle, ADD OIL (mix), ADD WATER (mix)
4. Beaker
   - ALL WATER SOLUBLE dissolved in water, & ALL SOLUBLE material dissolved in OIL
   - Heated on water bath
   - Internal phase added to external phase with mixing

Question 4

What are the 4 different types of ointment bases and give an example for each.

Answer 4

1. Oleaginous
   a. Drug release: POOR (b/c will hold tightly to that drug)
   b. Ex: White Petrolatum
2. Absorption (w/o)
   a. Drug release: Intermediate
   b. Ex: Lanolin
3. Water-removable (o/w)
   a. Drug release: Fair
   b. Ex: Hydrophilic ointment
4. Water-soluble
   a. Drug release: GOOD
   b. Ex: PEG ointment

Question 5

What are the different forms of formulations?

Answer 5

• Think about auxiliary labels for each thing we did in lab
• Be able to determine BUD based off table in lecture

Question 6

What are the 2 types of capsules based on their capsule shell? What are they composed of?

Answer 6

a. Hard Shell
- Gelatin
- Well suited to extemporaneous compounding)

b. Soft Shell
a. Contains a Plasticizer which may be a sugar or glycerol & more water ~30%
b. Require very specialized equipment

Question 7

Suspensions Advan/Disad:

Answer 7

Advantages as a dose form:
* Ease of swallowing for pt’s who cannot swallow solid dose forms
* Flexibility in giving doses of diff. sizes
* Disagreeable taste may be masked
* Drug may have INCREASED CHEMICAL STABILITY (even though unstable thermodynamic)

Disadvantages:
- PHYSICALLY UNSTABLE & will separate over time (if homogeneity not restored before use dosing inaccuracy will result)
- Pt may not like mouth-feel of product esp. if particle size is relatively large

Question 8

Semisolids Advan/Disad:

Answer 8

?

Question 9

Capsules advan/disad:

Answer 9

Advantages:
* Oral solids, tablets & capsules are most common dose form for adults
* Convenient to take & carry
* Readily identified & attractive appearance
* Efficient to fabricate, package & ship
* SOLIDS tend to be MORE STABLE than other dose forms

Question 10

Suppositories advan/disad:

Answer 10

Advantages for systemic use:
* Bypasses GI tract & 1st pass metabolism (get there faster)
* Drugs irritating to stomach can be given this way
* For pt unable to use oral route (vomiting, unconscious)

Disadvantage:
* Absorption erratic with inter-pt variability (b/c lots of factors affecting rectum)

Question 11

Transdermals advan/disad:

Answer 11

Advantages:
* Avoid (bypass) GI tract & 1st pass metabolism
* Can be used when oral route not possibl (pt can’t swallow or doesn’t want to )
* Non-invasive compared to parental route (easy to admin)
* Provide sustained release which may aid compliance or adherence
* Useful for administering drugs with a short half-life
* Therapy may be stopped rapidly by removal of the device
* Easily & rapidly identifiable since label on device

Disadvantages:
* Not all drugs will pass through the skin
* Can only be used for potent drugs where the dose is small
* Some pt’s do not tolerate the adhesive or some component (falls off or is itchy) & may develop contact dermatitis

Question 12

What are the desirable quanities of a suppository base?

Answer 12

• Must remain solid at room temp but soften, melt or dissolve at body temp

Question 13

Where does Transdermal target?

Answer 13

target organ is bloodstream

Question 14

What are the factors affecting absorption?

Answer 14

a. Higher [ ] of drug in the device, higher the rate of absorption

b. Larger the SA of device, amount of drug absorbed increases

c. Drug should have a greater attraction to skin rather than device matrix

d. Hydration of the skin usually favours percutaneous absorption so external side of device usually occlusive

e. Absorption more effect when device applied to skin with a THIN keratin layer

f. Longer device is left in place, the greater the total drug absorption

Question 15

What are the design features of FDDS devices?

Answer 15

1. Monolithic system
   * Drug is DISPERSED in a MATRIX b/t an occlusive backing & a frontal adhesive layer
   * Rate of release controlled by matrix & the way it interacts with the drug
2. Membrane-controlled system
   * A rate-controlling membrane b/t the MATRIX & the adhesive
   * Membrane is usually polyethylene with pore size suitable to give the desired rate of release

Question 16

If drug delieved to the skin SLOWER than absorption capacity, ______ is controlling rate of absorption

Answer 16

DEVICE

Question 17

If rate of release is FASTER than what the skin can absorb, the _____ is controlling rate of absorption

Answer 17

SKIN

Question 18

What are the advantages/disadvantages of TDDS?

Answer 18

Advantages:
1. Avoid GI tract & 1st-pass metabolism
2. Can be used when oral route is not possible
3. Non-invasive
4. Provide sustained release which may aid compliance or adherence
5. Useful for administering drug with a short half-life
6. May be stopped rapidly
7. Easily & rapidly identifiable since label on device

Disadvantages:
1. Not all drugs will pass through skin
2. Can only be used for potent drugs where the dose is small
3. Some patients do not tolerate the adhesive or some component & may develop contact dermatitis

Question 19

What is USP <795>?

Answer 19

• Pharmaceutical Compounding – Nonsterile
• Discusses:
  A. Responsibility of the compounder
  B. Facility standards & equipment
  C. Stability & BUD
  D. Ingredient selection & quality
  E. Checklist of considerations before compounding
  F. Discussion of procedures for diff dosage forms
  G. Records & documentation
  H. Quality control, verification & patient counseling
• When NO DATA is available, <795> states: Solids & non-aqueous liquids prepared from bulk ingredients – up to 6 months
• USP <796> requires:
  1. Formulation record (master formula)
  2. Compounding record for each compounding preparation (what you actually weighed)

Question 20

When to compound?

Answer 20

1. Patient-healthcare profesional relationship exits
2. May prepare drugs in v. limited quantities in anticipation of a prescription
3. Only do if there is a therapeutic need & lack of product avail.
4. Must not duplicate on approved drug product
5. When there is a shortage or no supply of a commercially avail. product
6. Cannot be sold for resale to 3rd parties, but pharmacies providing compounding services may contract this activity to another pharmacist
7. Should be compounded from an authorized drug or listed in a recognized Pharmacopoeia
8. Those engaged in sterile compounding should be knowledgeable & obtain specialized tech. training in this area
9. If providing to another hospital, should be within the same province, & you operate under the same hospital management board
10. Must comply with all relevant sections of the Food & Drugs Act
11. Expiration date based on known stability data. If not avail, use BUD

Question 21

What are the different levels?

Answer 21

14. Level A – designated & separate compounding area (like mixing 2 things – Antibiotic cream or something)

Level B – separate room ventilated or with containment device (a hood) – a lot of Pharmacies don’t have it

Level C – separate room under (-) pressure with containment device (means air in that room doesn’t go out – but air from outside goes inside)