Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
|
What is the definition of suppositories?
|
Solid bodies of various weights and shapes, adapted for introduction into the rectal, vaginal or urethral orifice of the human body. May act as a protectant or palliative to the local tissues at the point of introduction or as a carrier of therapeutic agents for systemic or local action.
|
|
|
What are examples of local application?
|
-hemorrhoids
-itching -infections |
|
|
What are examples of systemic application?
|
-antiepileptics
-antinauseants -antiasthmatics -analgesics -hormones |
|
|
What are the 3 advantages of rectal drug delivery?
|
1. self administration
2. avoidance of oral and parenteral administration 3. localized drug delivery |
|
|
What are the 5 disadvantages of rectal drug delivery?
|
1. Mucosal irritation
2. Patient Compliance 3. Erratic and undesired drug absorption 4. GI state affects drug absorption 5. Suppositories will be at ambient temperature |
|
|
What is the physiology? (7)
|
-tissue of rectum different compared to GI tract
-No microvilli -1.2 to 3 mL -pH= 6.8 -absence of carriers -vascularization of submucosal region -colon content |
|
|
What are the two ways drug is released from suppositories?
|
Oleaginous --> melts
Hydrophilic --> dissolve |
|
|
What are 3 factors that affect absorption?
|
1. Form of drug: salt form has faster release from fatty, lipophilic base than its unionized form
2. Particle size of drug: smaller=greater rate of absorption 3. Effect of concentration: increasing [drug] releases more drug into the rectal mucosa and rate of drug release increases. |
|
|
Uretheral suppositories
|
-5mm in diameter and 50 mm in length for females adn 125 mm for males
-weigh 2 g for females and 4 g for males -antiseptics, anesthetics -local action only |
|
|
What is an ideal suppository base?
|
-nontoxic, nonirritating, inert, compatible with medicaments, and easily formed by compression or molding
|
|
|
Suppository Bases
|
-should dissolve or disintegrate in presence of mucous secretions or melt at body temperature to allow for release of medication
-plays role in rate and extent of release of medications -Melt: fatty bases (Cocoa butter) -Dissolve: water soluble (PEG, Glycerin) |
|
|
Cocoa-butter (theobroma oil)
|
-most widely used
-innocuous - bland -non-reactive -melts at body temperature |
|
|
What are the disadvantages of cocoa-butter?
|
-does not mix with aqueous mucous secretions resulting in leakage from the site
-fatty acids can become rancid -melt in warm weather -liquefy with certain incorporated drugs -variable properties (natural product) |
|
|
What are the 4 polymorphs of cocoa butter?
|
- alpha mp 23 °C
-beta prime mp 28 °C -beta mp 34.5 °C -gamma mp 18.9 °C |
|
|
Suppository Bases (water soluble)
|
-glycerinated gelatin
-PEG suppository bases consist of blends of various MW -All water based bases must be preserved -hygroscopicity can cause stinging sensations and discomfort and probably affects the passage of drugs across the mucosa. |
|
|
what is glycerinated gelatin?
|
-useful suppository base, particularly for vaginal suppositories
-suitable for use with a wide range of drugs including alkaloids, boric acid, and zinc oxide -translucent, resilient, gelatinous solids that tend to dissolve or disperse slowly in mucous secretions to provide prolonged release of active ingredients -must be kept in well-closed containers in a cool place -should be dipped in water just before use -Incompatibility: Gelatin A and B: IEP: 7-9; 4.2-5 |
|
|
What is Polyethlylene Glycol?
|
-chemically stable, nonirritating, miscible with water and mucous secretions, and can be formulated, either by molding or compression, in a wide range of hardness and melting point
-dissolves at room temperature |
|
|
what are the 6 advantages of PEG?
|
1. PEG suppositories are easily made by fusion
2. liquid: 200-400 g/mol Solid: >100g/mol 3. they release hydrophilic and hydrophobic drugs 4. they do not support mold growth 5. Provide sufficient aqueous secretions in the body cavity, they provide more reliable release of drug than oleaginous bases 6. Because their melting point is easily controlled by appropriate blends, suppositories do not require carefully monitored storage temperature |
|
|
What are the 3 disadvantages of PEG?
|
1. Can be irritating to body cavity tissues
2. Incompatible with long list of drugs, especially those prone to oxidation 3. Interact with polystrene, often used for prescription vials so should not be dispense in these containers, unless the suppositories are first wrapped with foil. |
|
|
What are the 5 rationales for use of artesunate suppositories?
|
1. children with severe malaria unable to take tablets
2. Administering injections requires trained staff and equipment 3. Majority of malaria morbidity and mortality occurs in remote rural areas 4. safe and effective 5. potential to be administered at village level |
