L55 - Formulation Of Suppositories Flashcards
What are suppositories? (3)
- solid dosage form for admin of drug
- via rectum, vagina, urethra
- melt, soften, dissolve in body cavity
What are the different types of suppositories? (4)
- rectal
- infant
- vagina
- urethral
What are rectal suppositories like? (2)
- cylindrical, conical, tapered
- ~2g, 2.5-3.75 cm long
What are infant suppositories like?
~50% of adults
What are vaginal suppositories like? (2)
- various shapes
- ~3.5g
What are urethral suppositories like? (2)
- ~5mm diameter, female 50mm long, male 125mm
- 2g for female, 4g for male
What are the different application of suppositories? (2)
- local
- systemic
What are the local application of suppositories? (3)
- treatment of hemorrhoids
- itching
- infections
What are systemic application of suppositories? (5)
- for variety of drugs
- anti-nauseants
- anti asthmatics
- analgesics
- hormones
What are suppositories indicated for administering drugs to? (4)
- infants, small children
- severely debilitates patients
- cannot take meds orally
- parenteral route not suitable
What are physiological factors about rectal absorption? (3)
- fluid available for drug dissol ~3ml, 100mcm thick
- dissol of slightly soluble subs are slowest step
- rectal fluid neutral pH 7-8, no buffer capacity
What is suppository formulation like? (3)
- dissolved/dispersed drug in base at high temp
- poured into mould
- solidified at room temp
What are the types of bases drug dissolved/dispersed into? (4)
- oil of theobroma
- glycogelatin
- hydrogenated veg bases
- water soluble polyethylene glycol (PEG)
What are factors of physical chem of drug that influences choice of base? (3)
- drug solubility in vehicle
- particle size
- nature of the base
How does drug solubility in vehicle influence choice of base? (3)
- rate at which drug is released, solubility in vehicle
- partition coefficient of drug
- drug that is highly soluble in vehicle, release rate into rectal fluid is slow
How does particle size influence the choice of base? (3)
- undissolved - particle size influences rate of dissol, availability for absorption
- smaller = more rapid
- ideal - <50mcm
How does the nature of the nature of the base influence the choice of the base? (3)
- must melt, soften, dissolve for absorption
- if interacts - absorption impaired/prevented
- if irritates -initiate bowel movement = incomplete drug release, absorption
What are ideal properties of a suppository base?
- melts at body temp, dissolves in body fluids
- non
