No volume effect on retrograde colonic spread of rectally‐administered ropivacaine gel

Abstract

SUMMARYBackground: Rectal administration of enemas, foams and suppositories is the most efficient way to deliver locally acting drugs to the distal colon. Ropivacaine, a long-acting local anaesthetic, was chosen as a candidate for a new rectal treatment of ulcerative colitis. Aim: To determine the colonic spread of a rectal ropivacaine formulation. Methods: In this randomized, incomplete cross-over study, 12 male volunteers were given 200 mg ropivacaine HCl rectally in 20, 40, 60 and 80 mL hydroxypropyl methylcellulose gel. The viscosity of the gel was 1.1 Pa s. The spread of the radiolabelled ( 99m Tc-labelled diethylenetriaminepenta-acetic acid) formulations was

Distribution of Cell-Free and Cell-Associated HIV Surrogates in the Colon After Simulated Receptive Anal Intercourse in Men Who Have Sex With Men

“…Imaging with γ-emitting agents has been used to describe drug distribution after rectal administration 19–24 . Previously, we used SPECT/CT or MR with small molecule surrogate, diethylene triamine pentaacetic acid (393 g/mol) mixed into gels to describe colon distribution of microbicide surrogates following simulated RAI 9 .…”

Rectal microbicides: a new focus for HIV prevention

“…Also, imaging studies are somewhat artificial and do not provide definitive proof as to where viral transmission occurs. In addition, gastroenterologists routinely prescribe topical products (gels, enemas, foams and suppositories) that are able to deliver 5′ aminosalicylic acid to the left side of the colon in patients with ulcerative colitis 55 56. Hopefully, pharmacological experience with the design and delivery of 5′ aminosalicylic acid products can be used in the development of rectal microbicides.…”

A Comparative Pre-Phase I Study of the Impact of Gel Vehicle Volume on Distal Colon Distribution, User Experience, and Acceptability

“…The effect of product volume on distribution has previously been assessed in gel and enema studies using larger volumes of gel with widely varying viscosities. [13][14][15][16][17][18][19][20] One study found no difference in retrograde colonic distribution of 20 and 80 ml of rectally administered, radiolabeled ropivacaine gel. 13 Another study that examined a hypoosmolar product (FemGlide, 32 mOsm/kg) in men who practice RAI assessed the acceptability of four escalating volumes of a placebo gel from 5 to 50 ml and established that the maximum acceptable volume for use during RAI was 35 ml.…”