Rectal Delivery Part 1

Question 1

define suppository?

Answer 1

solid, bullet-shaped mass of drug with a base of either cocoa butter or hi-mw-PEG manufactured by casting

Question 2

Advantages of rectal admin for systemic therapy?

Answer 2

Drug-in-butt stability (DIBS)D – dysphagia/retainingI – irritationB – bypassS – stability

Question 3

disadvantages of rectal admin?

Answer 3

1) poor acceptance2) variable bioavailability3) difficult to titrate dose

Question 4

Function of rectum

Answer 4

continence & defecation (do not interfere with these)

Question 5

what is the distance from anus across stratified squamous epithelium to columnar epithelium?

Answer 5

2.5 cm

Question 6

describe rectal arterial blood supply

Answer 6

superior rectal artery (branch of inferior mesenteric artery)

Question 7

venous return for superior rectal vein?

Answer 7

inferior mesenteric vein –> hepatic portal

Question 8

venous return for middle/inferior rectal veins?

Answer 8

internal iliac –> IVC

Question 9

describe tonicity, volume, & pH of rectal fluids

Answer 9

pH = 7.2tonicity: isotonic, can deal with slight changesvolume = 3mL, can hold 30-60mL additional

Question 10

How much of rectal fluid is mucus?

Answer 10

1 - 2%

Question 11

function of mucus in the rectal cavity

Answer 11

lubricant

Question 12

describe properties of the two suppository vehicles

Answer 12

1) cocoa butter – melts @ 37C for slow, DR2) hi-mw-PEG – dissolves in fluids

Question 13

describe properties of rectal gels

Answer 13

concentrated solution of hydrophilic polymerbioadhesive

Question 14

how does suppository manufacture affect absorption?

Answer 14

1) manufactured – solution incorporated into melted base – drug moleculary dispersed in rectal cavity2) compounded – particles incorporated into melted base – drug particles dispersed in rectal cavity