Case 4 definitions Flashcards
temp at which suppositories melt, dissolve, soften
98.6F or 37C
cocoa butter
fat from the seeds of chocolate beans; natural TGs
cocoa butter advantages
non irritating and excellent emollient
cocoa butter disadvantages
poor and erratic release
stored at fridge temp
easily overheated = polymorph forms
PEG
water soluble base; do not melt at body temp but dissolve in body fluids; different hardness or dissolution is achieved by combining different kinds
glycerinated gelatin
mix of 70 pts glycerin; 20 pts gelatin, 10 pts water to create a soft rubbery consistency
PEG and glycerinated advantages
dissolve in 30-40 minutes
do not melt
do not leak
do not required monitored temperature
PEG and glycerinated disadvantages
irritating to body cavity tissues
cocoa butter melts between _____ it must be formulated
31-34; slowly and evenly without overheating due to possibility of polymorph forming
Wecobee or Witepsol
synthetic TGs less hard to formulate than cocoa butter but more expensive
Fattibase
composed of mixture of FAs; does not have formulation difficulties; less expensive than wecobee and witepsol but still more than cocoa butter
polybase
PEG mixture of 40% 8000 and 60% 400 used to create water soluble bases
glycerinated gelatin is
hygroscopic; it absorbs moisture from the air must be stored in airtight container
important factors to consider when selecting a suppository base
patient comfort: fatty bases = more comfortable
compatibility and stability
speed and consistency of drug release
oil sol drug + oil base =
slow release / poor escaping tendency
water sol drug + water base =
rapid erratic release
oil sol drug + water base
moderate release
water sol drug + water base =
moderate release based on diffusion
fatty bases are preferred for ____ and PEG bases are preferred for ____
rectal suppositories; vaginal and urethral suppositories
advantages of hand rolling suppositories
special equipment is not required
disadvantages of hand rolling suppositories
requires experience and good technique
final product does not have an elegant appearance
advantages for fusion method
does not require well developed compounding tech
final product is elegant
disadvantages for fusion method
special molds required
caution must be used with drugs sensitive to heat
there are a lot of calculations involved to do it correctly
practical aspects of dispensing suppositories
indicate route of administration
state preparation
aux labels should be used
rectal suppositories must be inserted passed the sphincter so they are not immediately ejected (1 inch in adult and 1/2-1 in children)
sit for 15 minutes and avoid emptying bowels for an hour unless its a laxative
rectal cavity
terminal portion of the colon; 8 inches in length composed of rectum, anal canal, anus
rectum
terminal section of the intestine; relative straight
serves as a transitional area from the colon to the external part of the body
simple columnar and cuboidal epithelium lacking microvilli + goblet cells
anal canal
last 1 inch of the rectal cavity
upper 2/3 of the anal canal
simple columnar epithelium
lower 1/3 of the anal canal
non keratinized stratified squamous then transitions to keratinized stratified squamous in the anus
rectal smooth muscle
outer layer of longitudinal fiber + inner circular layer
rectal cavity is has
a rich blood supply; venous return occurs through rectal hemorrhoidal veins
drugs carried by the superior hemorrhoidal veins
undergo first pass
drugs carried by the middle and inferior hemorrhoidal veins
bypass first pass
5 barriers to rectal drug delivery
unfavorable to passive absorption ( small SA and lack microvilli )
lacks dissolution media (when empty only contains 2-3 mL of fluid)
minimal buffering capacity (easily altered in pH with presence of drugs)
location influences first pass avoidance
occupancy and bowel movements affect drug absorptions (evacuated absorbs drugs better since there is a better chance of it reaching the surface; diarrhea and tissue dehydration can reduce drug absorption)
local conditions for rectal suppositories
inflamed hemorrhoids, constipation, UC
system conditions for rectal suppositories
nausea, fever, pain, motion sickness, epilepsy
general rectal dosage formulations
suppositories, ointments, creams, gels, solutions, suspensions
correct administration of an enemas
shake well
remove cover
assume correct position
insert tip
tilt so that the nozzle is aimed towards the back
squeeze bottle firmly with steady pressure
withdraw and discard
remain in position for 30 minutes retain enema all night unless its a laxative
advantages for rectal drug delivery
nausea and vomiting
no taste
bypass first pass
minimal enzyme activity
disadvantages for rectal drug delivery
interruption in absorption due to defecation
SA is v small
erratic and unpredictable
leak or can be difficult to retain in the rectal cavity
vaginal cavity
fibromuscular tube shaped organ of fixed length; 4-6 inches in size that connects to the uterus
inner canal of the vagina is
lined with stratified squamous epithelium and mucus produced by underlying glands; surface features micro ridges in longitudinal or circular patterns that give the vagina absorptive capacity
musculature of the vaginal cavity consists of three layers
outer fibrous
middle muscular
inner stratified squamous
muscles only used when a women is in labor therefore there is not a natural urge to contract and expel dosage forms as seen with rectal administration
blood flow travels from the vagina through a venous network that empties into the
internal iliac veins; bypassing first pass
vaginal cavity has a great amount of
buffering capacity; surface is covered with an aqueous film whose volume, pH, and composition vary with age, stage of mensural cycle and location; pH change high pH as you more in; large amounts of glycogen that forms organic acids upon degradation that serve to retard bacterial growth
local conditions for vaginal dosing
contraceptives, antiseptics, antimicrobial agents
systemic conditions for vaginal dosing
hormone replacement, prostaglandins, contraceptives
general vaginal dosage formulations
suppositories or pessaries, ointments, creams, vaginal tablets, intrauterine devices, contraceptive vaginal rings
vaginal suppositories
have an oviform; egg shape to encourage retention; heavier weight 3-5 g
advantages in vaginal drug delivery
fairly consistent drug absorption
option for local and systemic delivery
potential for long term administration
bypass 1st pass
disadvantages in vaginal drug delivery
dosage forms can be expelled
risk of toxic shock syndrome with long term retention
urethral route of drug administration
urethral suppositories are typically used to deliver antibacterials and anesthetics; muse (alprostadil) is a urethral microsuppository for treatment of ED
E value
equal to how much NaCl is represented by 1 g of the compound
E value =
58.5 * i / MW * 1.8
i
dissociation factor
