PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Rectal Absorption”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed1998

Enhanced colonic and rectal absorption of insulin using a multiple emulsion containing eicosapentaenoic acid and docosahexaenoic acid.

The aim of this study was to test the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on insulin absorption from rat intestinal loops in situ, using a water-in-oil-in-water (W/O/W) multiple emulsion. The enhancement effect of these long-chain polyunsaturated fatty acids was compared with that of free fatty acids having a C18 alkyl chain. The emulsion (insulin dose, 50 units/kg) was administered directly into the colonic and rectal loops. Both EPA and DHA strongly enhanced insulin absorption and induced hypoglycemia after colonic and rectal dosing. Comparing the pharmacological availability, the order of effectiveness with respect to the enhanced absorption of insulin was DHA >/= EPA > C18 unsaturated fatty acids >> C18 saturated fatty acid at both sites. DHA showed greater effects upon rectal dosing than upon colonic dosing. Histological studies revealed that the emulsion incorporating DHA did not induce gross morphological changes in the structure of the intestinal mucosa. Our results indicate that a W/O/W multiple emulsion incorporating DHA is a possible means of facilitating the intestinal absorption of insulin without inducing any serious damage to the epithelial cells.

Animals↗
PubMed1990

A comparison of oral and rectal absorption of L-dopa esters in rats and mice.

Short-chain alkyl esters of L-dopa were administered to rats and mice via oral and rectal routes. Plasma L-dopa esters and L-dopa were determined in the systemic and portal circulation by HPLC. A comparison of isopropyl, butyl, and 4-hydroxybutyl esters of L-dopa demonstrated significantly higher levels of the esters in both systemic and portal blood samples following rectal administration than following oral administration. In most cases, oral administration resulted in nondetectable (less than 0.01 micrograms/ml) levels of the esters in plasma. Correspondingly, the plasma levels of L-dopa itself were consistently higher following rectal administration. At very high oral doses (500 mg L-dopa equivalents/kg body weight), systemic plasma levels of the butyl ester could be detected (1.25 micrograms/ml at 10 min), which might indicate saturation of the esterase activity of the small intestine. These studies indicate that the systemic availability of L-dopa from short-chain alkyl esters of L-dopa may be best optimized by rectal administration, which avoids the relatively high esterase activity characteristic of the small intestine.

Administration, Oral↗
PubMed1993

Difference in rectal absorption of morphine from hollow-type and conventional suppositories in rabbits.

The bioavailability of morphine after rectal administration using three types of suppositories containing morphine hydrochloride (10 mg) in different added forms was evaluated in rabbits. Three types of suppositories were constructed with a base material (Witepsol H-15): a conventional suppository containing morphine hydrochloride mixed with a base material, a hollow-type suppository containing morphine in an aqueous solution in its cavity, and a hollow-type suppository containing morphine as a powder (hydrochloride salt) in its cavity. The plasma concentrations of morphine and its metabolites, morphine-3-glucuronide (M-3-G) and morphine-6-glucuronide (M-6-G), were determined. The mean AUC0-6 of morphine after rectal administration of the hollow-type suppository containing powdered morphine was significantly higher than that after the administration of a conventional suppository, whereas the mean AUC0-6 of M-3-G was lower than that after administration of a conventional suppository. The mean AUC0-6 of M-6-G by a hollow-type suppository containing powdered morphine was higher than that by a conventional suppository. Although the mean AUC0-6 ratio of M-3-G to morphine after administration of a conventional suppository was three times larger than that of a hollow-type suppository containing powdered morphine, the mean AUC0-6 ratios of M-6-G to morphine after use of the three types of suppositories were all approximately 1.0. This study demonstrates that the hollow-type suppository containing powdered morphine is a more effective rectal dosage vehicle than the conventional suppository.

Administration, Oral↗
PubMed1987

The synergistic effects of concurrent administration to rats of EDTA and sodium salicylate on the rectal absorption of sodium cefoxitin and the effects of inhibitors.

Plasma levels of cefoxitin, as enhanced by rectal coadministration of sodium salicylate, were reduced by concurrent administration of less than 0.5 mg mL-1 N-ethylmaleimide (NEM) or p-chloromercuriphenylsulphonic acid, sodium salt (p-CMP). Concentrations of these inhibitors above 1 mg mL-1 resulted in enhanced peak plasma values of cefoxitin. This did not occur after coadministration with either ethylenediaminetetraacetic acid (EDTA) or polyoxyethylene-23 lauryl ether (POE). Ouabain and 2,4-dinitrophenol (DNP) suppressed plasma cefoxitin levels in the presence of salicylate and the enhancing effects of EDTA and POE when EDTA and POE were administered at low doses. At higher concentrations of EDTA and POE, DNP had little effect, while ouabain had little effect on POE and only partially suppressed the effects of EDTA. Plasma concentrations of cefoxitin after coadministration with salicylate and POE together, or with EDTA and POE together, were about the same as expected from summing the plasma levels resulting from coadministration of each adjuvant individually at the same concentrations. However, combined administration of salicylate and EDTA with cefoxitin yielded plasma cefoxitin concentrations which were much higher than expected from the sum of their individual actions.

2,4-Dinitrophenol↗
PubMed1989

Rectal absorption enhancement of des-enkephalin-gamma-endorphin (DE gamma E) by medium-chain glycerides and EDTA in conscious rats.

The stability of the neuroleptic peptide des-enkephalin-gamma-endorphin (DE gamma E; Org 5878) in the rectal lumen and the rectal bioavailability of DE gamma E were investigated in conscious rats. Furthermore, the influence of peptidase inhibition, peptidase saturation, and absorption enhancement on DE gamma E bioavailability were evaluated. Na2EDTA (0.25%, w/v) prolonged the degradation half-life of DE gamma E in the ligated colon from 33 +/- 7 to 93 +/- 45 min. Without adjuvant, tritium-labeled DE gamma E was absorbed from the rat rectum to a very low extent (0-4%). After administration of an excess of unlabeled DE gamma E or with Na2EDTA, comparable results were obtained. The medium-chain glyceride preparation MGK markedly enhanced the rectal DE gamma E bioavailability, up to 8-20%, which was further increased to 10-44% by coadministration of Na2EDTA. No substantial influence of varying the rectal delivery rate was observed. The results suggest that absorption enhancement and enzyme inhibition both are essential for effective increase of rectal peptide bioavailability.

Absorption↗
PubMed1996

Combination effects of alpha-cyclodextrin and xanthan gum on rectal absorption and metabolism of morphine from hollow-type suppositories in rabbits.

Pharmacokinetics of morphine and its glucuronides in plasma were studied after rectal administration of hollow-type oleaginous suppositories containing kneading mixtures of morphine hydrochloride, alpha-cyclodextrin, and/or xanthan gum in rabbits. In combination with xanthan gum, alpha-cyclodextrin reduced the first-pass metabolism of morphine in the rectal mucosa and by the liver and improved the apparent rectal bioavailability of the opioid about 4 fold. In vitro permeation studies using an isolated rectal mucosal preparation of rabbits revealed that alpha-cyclodextrin increased the transepithelial conductance and facilitated the transport of morphine through the rectal mucosa. Furthermore, alpha-cyclodextrin facilitated its own mucosal permeation and reduced the glucuronidation of morphine during the passage through the rectal mucosa, probably through restricting the formation of a catalytic complex of morphine with glucuronyltransferases, rather than because of the enzyme saturation. The present data suggest that alpha-cyclodextrin in combination with xanthan gum is particularly effective in improving the rectal bioavailability of morphine from hollow-type suppositories.

Analgesics, Opioid↗
PubMed2000

Rectal absorption of lamotrigine compressed tablets.

PURPOSE: Interruption of oral drug administration poses a significant clinical problem for antiepileptic drugs that have no parenteral formulation. If a drug is absorbed rectally, rectal administration can be a useful alternative when the oral route of administration is not possible. The purpose of this study was to compare the single-dose pharmacokinetics of lamotrigine (LTG) compressed tablets after rectal and oral administration in healthy volunteers. METHODS: A single LTG compressed tablet (100 mg) was administered orally and rectally to 12 volunteers in this single-dose, two-period, crossover study with a 2-week washout between doses. For rectal administration, tablets were crushed and suspended in 10 mL of water. Plasma samples were collected from 0 to 120 hr after each dose and analyzed for LTG by an HPLC method developed for this investigation. RESULTS: LTG plasma concentrations were lower after rectal administration versus oral administration. The average area under the curve was 28.90 +/- 9.5 microg/mL/hr after rectal administration and 51.71 +/- 19.2 microg/mL/hr after oral administration. The average maximum LTG concentration was 0.53 +/- 0.14 microg/mL after rectal administration and 1.45 +/- 0.35 microg/mL after oral administration. The relative bioavailability for LTG compressed tablets was 0.63 +/- 0.33 for rectal administration. There were no drug-related rashes or serious side effects. CONCLUSIONS: LTG suspension prepared from LTG compressed tablets is absorbed rectally, although not to the same extent or rate as when given orally.

Administration, Oral↗
PubMed1991

[Effect of inclusion complexation of decanoic acid with alpha-cyclodextrin on rectal absorption of cefmetazole sodium suppository in rabbits].

Inclusion complex of decanoic acid (DA) with alpha-cyclodextrin (alpha-CyD) was prepared as an additive of cefmetazole sodium (CMZ) suppository and rectally administered to rabbits. The resulting complexation was examined by the phase solubility method, differential scanning calorimetry (DSC) and X-ray diffractometry. Plasma concentration and AUC of CMZ after rectal administration of a suppository containing DA/alpha-CyD complex to rabbits increased more significantly than those with none additive.

Adjuvants, Pharmaceutic↗
PubMed1989

Studies on sustained-release suppositories. I. Effect of alginic acid addition on rectal absorption of bacampicillin in rabbits.

Sustained-release suppositories of bacampicillin (BAPC) were prepared by the use of the adduct which was precipitated from an aqueous solution containing BAPC and alginic acid (Alg). As the suppository base, Witepsol H-15 and macrogol were used. Absorptions of BAPC from the suppositories were prolonged in rabbits, but the bioavailabilities were decreased compared to that after administration of BAPC alone. However, these absorptions were improved enormously by the addition of surface-active agents, that is, an excellent prolonged absorption and high bioavailability were obtained. Interestingly, similar prolonged absorption could be obtained only by mixing Alg with BAPC in a suppository base. Further, this absorption rate was found to be controlled by the amount of Alg addition. The absorption profiles from a suppository containing the mixture differed from that containing the adduct in exhibiting both high plasma level and prolonged absorption. This may be due to simultaneous fast absorption of BAPC itself and formation of the adducts. Thus, it seemed that BAPC preparations containing Alg may be practically useful as a rectal preparation with prolonged action and giving a high plasma level.

Alginates↗
PubMed1988

Release and rectal absorption of ethosuximide from suppositories in rabbits.

Ethosuximide was formulated in different suppository bases. In vitro release experiment demonstrated more rapid and higher release of the drug from water soluble polyethylene glycol (PEG) bases than from Witepsol fatty bases. Rectal administration in PEG 400:4000 and 400:6000 to rabbits gave high plasma levels where Cmax was 45.66 and 42.66 micrograms.ml-1, respectively; while, in the presence of Witepsol E76 and W35 it was 34.00 and 28.33 micrograms.ml-1, respectively. The systemic availability was 89.39%, 82.72%, 58.80% and 47.45% when the bases were PEG 400:4000, PEG 400:6000, Witepsol E76 and Witepsol W35, respectively.

Animals↗
PubMed1993

Investigation on rectal absorption of indomethacin from sustained-release hydrogel suppositories prepared with water-soluble dietary fibers, xanthan gum and locust bean gum.

Sustained-release hydrogel suppositories prepared with water-soluble dietary fibers, xanthan gum and locust bean gum, were evaluated as a vehicle for rectal administration of indomethacin (IMC) in rabbits. The drug plasma levels were compared with those after rectal administration of commercial suppositories. When the commercial suppositories were given to rabbits, the plasma concentration reached the maximum level at 30 min after administration followed by a quick reduction, while no sharp peak of plasma levels was seen with the hydrogel suppositories. In particular, the plasma levels observed with the hydrogel suppositories of 1% (w/v) gum concentration were sustained much longer than those after dosing with the commercial suppositories; the mean residence times had higher values without a decrease in the area under the plasma concentration vs. time curves. Histopathological study showed good biological safety of the hydrogel suppositories to the rectal mucosa. These results suggested that the IMC hydrogel suppositories prepared with xanthan gum and locust bean gum were a practical rectal preparation with prolonged action and reduced side effects.

Animals↗
PubMed1985

[Rectal absorption of steroids].

The investigations were designed to evaluate the systemic absorption of two steroids from suppositories. The suppositories containing either 3H-hydrocortisone (1 mg) or 3H-prednisolone-21-hexanoate (1 mg) were administered to a group of 4 baboons restrained in chairs. The levels of radio-activity in the plasma and urine were measured up to 120 h following rectal administration, and these levels were compared with those of a subsequent intravenous administration (1 mg each). The results show that both hydrocortisone (H) and prednisolone-21-hexanoate (P) are rapidly (tmax = 2-3 h) and significantly (H: 60-78%, P: 47-58%) absorbed from suppositories and thus can also cause systemic effects.

Animals↗
PubMed1994

Improvement of aqueous solubility and rectal absorption of 6-mercaptopurine by addition of sodium benzoate.

The solubility of 6-mercaptopurine (6-MP) in water increased as the concentration of sodium benzoate or sodium hippurate in the solution increased. The solubility of 6-MP in 20% (w/v) sodium benzoate or sodium hippurate solution was about 6-fold larger than that of 6-MP alone. The stability constant of the soluble complex of 6-MP with sodium benzoate was estimated to be 2-8 M-1 from (1) phase-solubility study and (2) analysis of chemical shifts observed in 1H-NMR. Partition of 6-MP from the saturated solution to n-octanol was also greatly increased by the addition of sodium benzoate or sodium hippurate, the degree being less in the latter. Administration of 6-MP with 20% (w/v) sodium benzoate to rat rectum resulted in enhanced absorption and the area under the plasma concentration-time curve was comparable to that obtained by intravenous administration (bioavailability = 100%), while the bioavailability after intrarectal administration of 6-MP with 20% (w/v) sodium hippurate was only 9%. The reason for the difference was discussed.

1-Octanol↗
PubMed2006

Optimization of suppository preparation containing sodium laurate and taurine that can safely improve rectal absorption of rebamipide.

We previously reported that the fatty base suppository containing sodium laurate (C12) and taurine (Tau) (C12-Tau suppository) could enhance the colonic absorption of rebamipide, a poorly water-soluble and poorly absorbable drug, without any serious mucosal damages in rats. In the preset study, in order to make C12-Tau suppositories available for practical use, the scaling-up studies of animal and formulation size were performed, compared with the suppositories containing sodium caprate (C10) (C10 suppository) at the same amounts as those contained in the commercial products. Twenty-mg C12 improved the dissolution of rebamipide from suppository remarkably and the addition of 30-mg Tau only slightly decreased the dissolution rate. The absorption of rebamipide from rabbit rectum was more markedly improved by suppositories containing C12 than C10 suppositories. Although Tau tended to attenuate the absorption-enhancing effect of C12, several C12-Tau suppositories kept high bioavailability values, which were much higher than control. Histopathological studies showed that Tau exerted the cytoprotective action and that C12-Tau suppositories were better than C10 suppositories in safety. Considering the balance between efficacy and safety, the suppository containing 10- or 20-mg C12 with 30-mg Tau is better than C10 suppositories as commercial products and could be promising for practical use in human.

Administration, Rectal↗
PubMed1985

Comparison of the effects of sodium salicylate, disodium ethylenediaminetetraacetic acid and polyoxyethylene-23-lauryl ether as adjuvants for the rectal absorption of sodium cefoxitin.

Sodium salicylate, disodium ethylenediaminetetraacetic acid (EDTA) and polyoxyethylene-23-lauryl ether (POE) significantly enhanced the absorption of cefoxitin from the rectum but with the following differences. The effectiveness of salicylate or EDTA was enhanced by sodium chloride, whereas the activity of POE was not. Although the ratios of plasma cefoxitin peak values to cefoxitin dose were constant with POE or EDTA, the peak to dose ratios with salicylate decreased with increasing cefoxitin concentration. Phlorizin and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) inhibited the effectiveness of salicylate, but did not influence the adjuvant action of either POE or EDTA. Although treatment with salicylate resulted in slightly less protein release than treatment with NaCl, both POE and EDTA increased the release of protein from the rectal mucosa. It appears that the effects of salicylate occur at the protein fraction of the rectal mucosa through a saturable process whereas the adjuvant action of POE and EDTA appears to involve some irreversible disruption of the membrane.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗