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101 Cards in this Set

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What is a suppository?
A solid dosage form intended to be inserted into various body orifices where they melt, dissolve, or disperse to exert local or systemic effects.
Name the possible sites of insertion for suppositories.
1. Commonly rectal or vaginal

2. Occasionally urethral
Sizes of rectal suppositories for children vs. adults?
Adult = 2g

Children = 1g
The possible shapes of rectal suppositories?
Bullet, finger, or torpedo
Size of vaginal pessaries?
5 g
Shape of vaginal pessaries?
Globular, oviform. More rounded than rectal suppositories.
Size of urethral bougies for males verses females?
Males = 4 g

Females = 2 g
Shape of male bougies?
Pencil shaped. 3-6 mm diameter and 140 mm long.
Suppositories are used to attain what kind of effect?
Either Local or Systemic.
Some local effects of rectal suppositories?
1. Pain, irritation, itching, inflammation associated with steroids

2. Local anesthetic, vasoconstrictor, astringent, analgesic, soothing, emollients, protective agents.

3. Relief of constipation
Give 2 examples of rectal suppositories used for constipation relief?
1. Glycerin

2. Bisacodyl
Some local effects of vaginal suppositories?
1. Contraceptives

2. Antiseptic

3. Antifungal

4. Yeast infection
Some local effects of urethral suppositories?
1. Antibacterial

2. Anesthetic before preparation for urethral examination.
The systemic effects of rectal suppositories involves these steps?
Absorption involves 2 steps:

1. Release of drug from vehicle, diffuse through the mucosa

2. Drug transports through the veins, lymph vessels and into systemic fluids or tissues
Suppositories are useful alternatives to the oral route of administration for these medications?
1. Aminophyline and theophyline for asthma.

2. Prochlorperazine and chlorpromazine for relief of nausea/vomiting, and as a tranquilizer.

3. Aspirin and acetaminophen for analgesic and antipyretic (reduce fever) effects.
5 advantages of rectal suppositories?
1. Avoid first pass effect (So avoid losing drug through liver processing)

2. Avoid possible drug inactivation by GI pH or enzymatic activity

3. Drugs will not irritate stomach (ex. Aspirin, Indomethacin diclofenac)

4. Patients who are not able to swallow

5. Patients who are vomiting
List 3 disadvantages of suppositories?
1. Un-comfort

2. Variation of absorption

3. Irritation to mucous membranes by some bases or drugs.
Elaborate on how variation in absorption is a possible disadvantage of suppositories?
The rectum is 15-20 cm long. There is variation in blood vessel distribution. So absorption depends on where it is inserted. Blood vessels tend to congregate in the center.
Basic composition of suppositories?
1. Active drug

2. Base

3. Additive
2 general factors that affect the absorption of suppositories?
1. Physiological factors

2. Physiochemical factors
List 4 points about the physiology of the rectum?
1. Rectum is 15-20 cm

2. 2-3 mL of mucus

3. Not mobile in resting state, no villi or microvilli

4. High viscularization (High blood flow)
List 3 physiological factors that may affect the absorption of suppositories?
1. Colonic content

2. Circulation route

3. pH and lack of buffering capacity.
Explain how colonic content can affect the absorption of suppositories?
If it is empty verses distended with fecal matter affects absorption. Fecal matter can remove drug. Also diarrhea and colonic obstruction due to tumorous growth can affect absorption.
How does the circulation route affect the absorption of suppositories?
It can bypass the portal circulation and be circulated by hemorrhoidal veins and lymphatic circulation.
How does pH and lack of buffering capacity affect the absorption of suppositories?
pH is neutral. So no chemical change will happen to the drug.
What are the physiochemical factors that must be considered when considering the drug for a suppository?
1. Lipid water solubility

2. Particle size
Would you want a lipophilic drug in an oleaginous base for a suppository?
No. The drug would be more attracted to the base and would not be absorbed.
What is the nature of the ideal base for a suppository? (5)
1. The base should be nontoxic and not irritable to the mucous membrane.

2. It should be compatible with the variety of drugs that are used in suppositories.

3. It should melt or dissolve in rectal fluids.

4. It should be stable on storage, it should not bind or otherwise interfere with the release and absorption of drug substances (ie. it should be inert)

5. It should be easy to handle and be cost effective.
Name 3 problems that may be encountered with the base of a suppository?
1. Base may interact with the drug

2. Base does not release the drug

3. Base irritates the mucous membrane and promotes bowel movement.
Name the 3 classes of Supp. Bases.
1. Fatty or Oleaginous (hydrophobic) bases

2. Water soluble and water miscible bases

3. Misc. bases (combo of lipophylic and hydrophilic)

(This class will focus on 1 and 2)
Fatty or Oleaginous bases are the ? ? used bases.
The most frequently used.
How do fatty and oleag. bases melt at body temperature?
They allow quickly. This allows the drug to be released and absorbed.
Are fatty and oleag. bases irritating at all?
No, they are mild and non-irritating.
Fatty or Oleag. bases allow for a rapid release of what kind of drugs?
They allow for a rapid release of water soluble drugs.
What is basically the most ideal base used for suppositories?
Cocoa butter. It is the most commonly used.
Besides Cocoa butter, list some examples of fatty or oleaginous bases used in the preparation of suppositories?
1. Hydrogenated Fatty Acids of vegetable oil (palm kernel oil or cottonseed oil)

2. Glycerin and High MW fatty acids, Glyceryl monostearate and glyceryl monopalmitate.
Where does cocoa butter come from?
It is natural, from the roasted seed of theobroma cacao.
What is the color of Cocoa butter?
It is a yellowish-white solid.
At what temperature does Cocoa butter melt at?
It melts at 30-36 degrees celsius. This is a little below body temperature.
Cocoa butter is a triglyceride. What does this mean?
It is composed of a combo of glycerin and one or more different FAs)
Cocoa butter, NF exhibits ? ? ? and commonly exists in ? forms.
It exhibits different crystal forms and commonly exists in four forms.
Cocoa butter is a polymorph. What does this mean?
It has different crystal forms but the same chemical constitution. This has an effect on the m.p. It becomes an issue when we overheat cocoa butter.
Does cocoa butter require lubrication when it is the base for a supp.?
No, Because it is fatty/oleaginous.
Name 3 additives that are added to Cocoa butter bases?
1. Phenol

2. Camphor

3. Chloral Hydrate

These are all added for other purposes but they all happen to lower m.p.
What may be added to cocoa butter bases to thicken them?
1. Beeswax

2. Cetyl Ester Wax
Substances that are said to be polymorphic exist in what state?
They exist in different crystalline forms.
The different crystalline forms of a polymorphic substance have what differences between forms?
They differ in melting points and solubility.
How must cocoa butter be melted?
Slowly and evenly. Not at a high temp.
What occurs if cocoa butter is overheated?
If overheated lower M.P. crystals will form on cooling and the mix may not solidify at room temperature.
When overheated what form of cocoa is derived?
Alpha form is derived. It has a low m.p.
What form of Cocoa butter do we aim for in preparations?
We want the Beta form. It is the most stable for our purposes.
What is the melting point of the Beta form of cocoa butter? What is the m.p. of the Alpha form?
Beta Form = 30-36

Alpha Form = 22
List 6 disadvantages of cocoa butter?
1. Polymorphism

2. Poor water absorptive power

3. Pitting due to contraction on cooling

4. Rancidity (40% of FAs are unsaturated, lends to chemical instability)

5. Softens at low temperatures (28-30)

6. Batch to batch variability due to natural origin.
Due to Cocoa butter limitations, what is available?
Many combinations of FATS and WAXES are available to be used as substitutes.
List 3 examples of Cocoa butter substitutes?
1. Fattibase

2. Wecobee bases

3. Witepsol bases
Why is the cocoa butter substitute Fattibase desirable?
It is more stable than cocoa butter because it is not made of unsaturated fats. It is saturated.
Name 6 Advantages of Cocoa butter substitutes over cocoa butter?
1. No polymorphism

2. Higher M.P. range possible (33-37.5)

3. Rancidity corrected (Due to the fact that the substitutes are mostly saturated rather than unsaturated fats)

4. More reproducible

5. Better contraction (So better looking)

6. Enhanced ability for water uptake.

7. Rapidly solidify
List 2 bases that are water-soluble and water-miscible?
1. Gycerinated gelatin

2. Polyethylene glycols (PEG)
What is Gycerinated gelatin and what is it composed of?
It is a base that is both water soluble and water miscible. It is composed of 10% Drug solution + 70% Glycerin + 20% Pharmagel A or B.
What are Pharmagel A and Pharmagel B?
They are different sources of gelatin. A is from acid hydrolysis of skin. B is from base hydrolysis of bone.
Cocoa butter tends to ? ? orifice.
Tends to leak from the orifice.
What kind of suppositories are glycerinated gelatins used for?
They are commonly used for vaginal supp's. It is slower to soften and mix with physiological fluids.
What is the difference between Glycerinated gelatins used for vaginal suppositories verses those used for urethral supp's?
Urethral suppositories using glycerinated gelatin have more gelatin than the vaginal variety. Urethal are composed of 20% drug solution, 60% gelatin, and 20% glycerin.
Does glycerinated gelatin display the property of poymorphism like cocoa butter does?
No
What needs to be done to a glycerinated gelatin supp. before insertion?
It needs to be moisturized with water before insertion. Otherwise, it could cause irritation by absorbing fluid.
Glycerinated Gelatins tend to have a ? dissolution. This makes them best suited for a ? effect.
They tend to have a slow dissolution that is best suited for a local effect.
What needs to be done to glycerinated gelatins if they are not intended for immediate use?
They need to be preserved. Parabens may be used to accomplish this. Refrigeration is reqd for these.
What may overheating of glycerinated gel supps lead to?
It may lead to a release of volatile toxic vapors.
What is polyethylene glycol?
It is another example of a base that is water soluble and miscible. Also referred to as PEG, Carbowax. It is commonly used.
What is PEG composed of?
It is a polymer of ethylene oxide and water.
What is the M.W. of PEG?
Range from 300-8000
Which varieties of PEG are clear liquid at room temperature?
PEG 300, 400, and 600
PEGs that are <1000M.W. are ?. PEGs that are >1000M.W. are ?.
PEGs less that have a mw less than 1000 or liquid. PEGs that have a mw greater than 1000 are wax-like solids whose hardness increases with mw.
Are PEGs water soluble?
Yes, but dissolution is slow.
Do PEGs require a preservative?
Yes, Paraben can be used to preserve.
Remember, the term PEG is interchangeable with what?
Polyethylene glycol or Carbowax
Name 7 advantages of water-soluble/water-miscible bases?
1. mp~40C (This makes them easier to handle)

2. Slowly melt and release. (An advantage if you desire a slower release)

3. Ratio adjustment for a suitable base. ie, you can combine PEGs with different mw until you get the type of base you desire.

4. Not sticky

5. Appropriate for hydrophilic and lipophilic drugs

6. High viscosity

7. Easy storage
Name 5 disadvantages of water-soluble/water-miscible bases?
1. High mw PEG has a slow release of ~25-30 minutes.

2. Tendency to sting. This is because they absorb water from the mucous membrane. This is why they need to be dipped in water before insertion.

3. Contraction on cooling. They get cavitation at the ends like the pitting of cocoa butter.

4. They interact with polystyrene. This limits the molds that can be used.

5. They are incompatible with many drugs.
Give 2 examples of drugs that water-soluble/water-miscible bases are incompatible with?
1. Aspirin degrades faster in PEG than in cocoa butter

2. Indomethacin and PEGs
List the 3 methods of suppository preparation?
1. Molding

2. Compression

3. Hand rolling
What is molding aka?
Fusion
List the 5 steps of molding?
1. Melt the base using minimum heat in water bath.

2. Incorporate medication

3. Pour into the mold

4. Allow to cool. May be refrigerated.

5. Remove from the mold
How would you incorporate a volatile drug into a mold?
If a drug is volatile or thermo-labile it should be added at the CONGEALING point.
How should a supp. prep. be poured into a mold?
In a continous stream with stirring. Over filling should be avoided.
How should a supp. be removed from a mold?
Usually with no pressure applied.
What is not involved in the method of compression?
No heating involved. You are forcing the base and the medication into a special mold.
How does the base soften in the method of compression if heat is not applied?
It is softened by friction. Mortar and pestle may be used.
What are two advantages of the method of compression for supp. making?
1. May use heat-labile medication

2. No medication can precipitate at the bottom of the mold
What are the 2 disadvantages of using compression to make supps?
1. Requires the use of a special machine.

2. LImitation of the suppository shape.
What 2 bases are commonly used in the compression method of making supps?
PEG and cocoa butter
What is the most common way of making supps?
Fusion (molding)
What is the historic method of making supps?
Hand-rolling
What does the process of hand rolling help avoid?
Helps to avoid the necessity of heating cocoa butter.
How is a "plastic-like mass" formed in the process of hand rolling supps?
You would triturate cocoa butter and the active ingredient in a mortar.
What size and shape are supp. molds available in?
A variety of shapes and sizes.
What are supp. molds commonly comprised of?
1. Aluminum

2. Stainless steel

3. Brass

4. Plastic

5. Rubber

6. Foil paper
What base does not need lubrication when it is molded?
PEG and Cocoa butter do not need lubrication. This is because they contract.
What type of base needs a lubricated mold? What is an option for lubrication?
Glycerinated gel bases may need a lubricated mold. You may use mineral oil to achieve this.
Each mold is capable of holding specific volumes. What size is desired for adults? What size is desired for children?
Adults = 2g

Children = 1g
What is the reason for calibrating molds?
To account for the fact that bases and drugs have different sizes and densities.
In the calibration of a mold, Active drug with ? ? ? volume is considered insignificant.
Active drug with < 100 mg of drug is insignificant.