Suppositories (Cut off for Exam 1) Flashcards
1
Q
Suppositories
A
- Solid Dosage Forms intended for insertion into body cavities where they soften, dissolve, or melt and exert local or systemic effect
- Commonly used rectally and vaginally, though can also be sometimes used urethrally
- Various shapes and sizes, must insert into orifice without distension then retain its position for proper amount of time
2
Q
Local Action + Rectal
A
- Constipation - glycerin promotes laxation by local imitations of mucous membrane with dehydrating effects
- Pain, itching, hemorrhoid inflammation - anesthetics, vasoconstrictive astringents, emollients, and protective agents
3
Q
Local Action + Vaginal and Urethal
A
- Vaginal - contraception, antiseptics, antibacterials, antifungals
- Urethra - Antibacterial or local anesthetics in preparation for urethral exam
4
Q
Systemic Action
A
-Mucous membrane of rectum and vagina permits absorption of soluble drugs into blood stream.
5
Q
Suppository Advantages (5)
A
- Avoid low pH of stomach
- Avoids first pass metabolism
- Avoids irritation of stomach
- Effective route in treatment of patients with nausea
- Allows for drug administration in patient who can’t or who refuse to swallow
6
Q
Absorption + Physiological Factors
A
- Colonic content - increased absorption in void colon
- Circulation route - abundant vascularization of submucosa region of rectum wall with blood and lymphatic vessels
- pH and lack of buffering - rectal fluids are neutral with no buffer capacity, drugs need to be unionized when inserted
7
Q
Absorption + Physicochemical Factors
A
- Lipid/Water Solubility - lipophilic drugs in fatty base has a decreased tendency to escape to surrounding aqueous fluid than hydrophilic drugs
- Particle size - smaller particles have increased rate of dissolution and absorption
- Nature of the bases - fatty and water soluble, must be able to melt to release drug and not inhibit its release, must not irritate membranes else it could initiate a bowel movement that could expel the suppository
8
Q
Suppository Bases
A
- Analogous to ointment bases
- *Must be solid at room temperature and soften/dissolve/melt at body temperature
- Fatty bases (Cocoa butter) - lipophilic drugs tend to remain in base while hydrophilic drugs release and absorb into the tissue
- Water soluble bases (Glycerated gelatin) - dissolve slowly in body fluids and release lipophilic drugs readily
9
Q
Calibration of Suppository Molds
A
- Individual molds hold a specific volume
- Differences in density between bases will result in differences in weights of suppositories with the same volume
- Pharmacists should calibrate the mold for the usual base (cocoa butter or PEG)
10
Q
Preparation of Suppositories
A
– Melting the base
– Incorporating any required medicaments
– Pouring the melt into molds
– Allowing the melt to cool and congeal into suppositories
– Removing the formed suppositories from the mold
11
Q
Fatty or Oleaginous Bases
A
- Most frequently employed (cocoa butter)
- Hydrogenated fatty acids of vegetable oils, EX: Palm kernel or cottonseed oils
- Glycerin with high weight fatty acids, EX: Palmitic or stearic acids
- Combinations used to obtain desired hardness for storage and transportation and desirable melting characteristics
12
Q
Cocoa Butter Problem
A
- Exhibits polymorphism: existence in several crystalline forms
- When heated too rapidly to a temp much higher than melting point and then quickly chilled, forms α crystals
- Must melt slowly and evenly (water bath) to avoid
formation of the unstable crystals
13
Q
Alpha Crystals
A
- α crystals have a much lower melting point and may not solidify at room temp
- α crystals are a metastable form and slowly will revert back to β crystals, but this may take place over several days
14
Q
Water-soluble Bases
A
- Glycerinated Gelatin
2. Polyethylene Glycol
15
Q
Glycerinated Gelatin
A
- Gelatin (20%), glycerin (70%), and solution or suspension of drug (10%)
- Most frequently used in the preparation of vaginal
suppositories where prolonged local action is desired - Protect from atmospheric moisture
- Should be moistened prior to insertion to avoid irritation
16
Q
Polyethylene Glycol
A
- Polymers of ethylene oxide and water with various chain lengths, molecular weights, and physical characteristics
- Vary from low weight PEGs that are clear, colorless liquids to high weights (> 1000) are wax-like, white solids with increasing hardness
- Mixed by fusion to achieve base with desired consistency and characteristics
- Do not melt at body temp, but slowly dissolve in body fluids
17
Q
Rectal Suppository Counseling
A
- If stored in refrigerator, allow to come to room temperature before insertion
- Rub cocoa butter suppositories gently with fingers to melt the surface and provide lubrication for insertion
- Glycerinated gelatin or PEG suppositories should be moistened with water to enhance lubrication and decrease irritation
- Remove all wrappings completely before insertion
18
Q
Vaginal Suppository Counseling
A
- Read all instructions
- Insert suppository high in the vagina with provided applicator
- Notify physician if burning, itching or signs of allergic reaction occur
- Because suppositories are commonly administered at bedtime and can be messy, instruct patient to use a sanitary napkin to protect nightwear and bed linens (if using an oleaginous base)
19
Q
Rectal Suppository Shapes/Sizes
A
- 32 mm (1.2 in) long, cylindrical and have one or both ends tapered
- Weight will depend on density of base and drug, but adult cocoa butter suppositories weight about 2 grams
20
Q
Vaginal Suppository Shapes/Sizes
A
- Usually globular, oviform, and cone shaped
- Weigh about 5 grams
21
Q
Urethral Suppositories Shapes/Sizes
A
- Slender, pencil shaped
- Male: 3 to 6 mm in diameter, 140 mm (5 in) long, and weigh 5g
- Female: half the length and weight
