-
-
dosage forms
- suppositories
- solutions
- ointments
-
rectal route - advantages:
- patients who suffer from extream nausea and vomitting
- unconsious patients
- pediatrics
- no taste limitations
- hepatic (liver) bypass
- gastric (stomach) bypass
-
rectal route - disadvantages
- absorption interrupted by pooping
- small surface area
- inconvenient
- absorption can be erratic and unpredictable
- "leakage" or expelled after insertion
-
shapes and sizes (rectal)
- torpedo (pointed end tapered to blunt end)
- adult: 20mm, 2g
- child: 10mm, 1g
- max amound of solid materal is 30% of blank weight
- **no more than 500mg can be incorporated into rectal suppositories
-
rectal suppositories effects
- local: treats hemmoroids, inflammation
- systemic: treats fever, pain, infection
*drugs are absorbed via passive diffusion
-
factors that affect absorption of rectal supp.
- site
- absorption enhancer used
- colonic content
- suppository base used
-
vaginal supp. advantages
- less toxic (less absorption than oral)
- dose can be retrieved
- long term administration (IUDs)
- improved compliance
-
vaginal supp. disadvantages
- absorption can be variable (depending on viability of vaginal walls)
- toxic shock
- can be expelled
-
vaginal formulations
- solutions
- powders for solutions
- ointments, creams
- aerosol foams
- supp. (globule, oval shaped, blank weigh 3-5g)
-
vaginal formulation uses
- contraceptives
- feminin hygeine antiseptic
- bacterial antibiotic
- restore vaginal mucosa
-
urethral administration
- not very common
- inserted into urethral
-
urethral uses
- antibacterial
- local preparative anesthetics
- erectile disfunction
-
suppository bases: ideal materials
- non-toxic
- non-irritating
- inert
- compatible
- easily pilable into desired shape
-
suppository base classes
- 1: oleaginous (fatty)
- 2: water soluble or miscible
-
types of oleaginous bases
- 1: theobroma oil (cocoa butter)
- 2: synthetic triglyceride mixtures
-
theobroma oil (cocoa butter)
*base not heated over 35oC *adding phenol lowers melting point*adding beeswax raises melting point
-
synthetic triglyceride mixtures
- not same formulation of cocoa butter
- doesnt exhibit polymorphism, *contolling temp. not important
- Ex: Wecobee, MBK, FattiBase
-
types of water soluble/miscible bases
- glycerinated gelatin
- polythylene glycol (PEG) polymer
-
glycerinated gelatin
- add preservatives: methylparaben
- supp dipped in water before use
- translucent, resilent, gelatinous
- provide prolonged release of A.I.
- store in sealed containers, will absorb and dissolve in atmospheric moisture
-
polyethylene glycol (PEG) polymer
- chemically stable, nonirrating, miscible in water and mucous secretions
- can be formulated by molding or compression in wide range of hardness and melting points
- do not melt at body temp.
- dissolve to provide more prolonged release than cocoa butter
-
methods of prep
- hand rolling: cocoa butter base
- compression: forced into special compress
- fusion: melt, disperse drug into melted base, pour into mold
-
instability of suppositories
- excessive softening
- hardness
- dried out
- oil staining on packaging
-
storage
- protect from heat
- refrigerate (do not freeze)
- glycerin and PEG kept in tight sealed container
|
|
