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 91 records · Page 5Linked to original sources
PubMed1977

Rectal absorption of nitrofurantoin.

The adsorption in humans of nitrofurantoin from seven suppository bases was studied using urinary excretion measurements. Rectal absorption was poorer than GI absorption. The administration of 400 mg of nitrofurantoin in a polyethylene glycol-polysorbate 80 suppository base and in a polyethylene glycol-silica suppository based provided an adequate urinary concentration of nitrofurantoin. Persons who cannot tolerate orally administered nitrofurantoin due to gastric upset could receive nitrofurantoin therapy rectally.

Administration, Oral↗
PubMed1990

Influence of the hydrophilicity of suppository bases on rectal absorption of carprofen, a lipophilic nonsteroidal anti-inflammatory drug.

The influence of the hydrophilicity of fatty suppository bases on the rectal absorption of the lipophilic drug carprofen (octanol-buffer, pH 7.4; partition coefficient, 40) was investigated in dogs. Five animals received each of six carprofen formulations in a random sequence: intravenous, oral, and rectal solutions, and three suppository formulations. The suppository vehicles tested were semisynthetic glycerides containing saturated fatty acids mainly in the range of C10 to C18 [Massa Estarinum A (MEA), Massa Estarinum B (MEB), and Massa Estarinum 299 (ME299)]; their hydroxyl values increased from 1 for ME299, through 24 for MEB, to 45 for MEA. Following every drug administration, blood samples were collected over a period of 104 h and carprofen plasma concentrations were measured by a specific HPLC method with UV detection. The rate and extent of carprofen absorption were characterized by evaluation of the maximum plasma concentrations (Cmax), the time of their occurrence (tmax), absolute bioavailabilities, statistical moments, and by deconvolution. Carprofen was rapidly and completely absorbed from the oral solution. The maximum concentrations obtained with oral solutions were significantly higher than those observed with rectal solutions and with the three suppository formulations. Results obtained with the rectal solution exhibited a high degree of intersubject variability. After rectal administration of suppositories, the rate and extent of carprofen absorption increased with the hydroxyl value of the suppository base; the mean absorption times (MAT) and tmax were shorter with MEA (2.15 and 1.7 h, respectively) than with the less hydrophilic vehicles (MEB: 4.09 and 2.1 h, respectively; ME299: 4.22 and 2.4 h, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Effects of salicylate and other enhancers on rectal absorption of erythropoietin in rats.

To develop a new treatment for patients with anaemia in which erythropoietin (EPO) can be given without injection, the effects of promoters of the rectal absorption of EPO were studied. Recombinant human (rHu) EPO (5000 units) in a dosing solution or in a rectal suppository was placed in the rectum of healthy rats and changes in serum EPO levels were monitored by an enzyme-linked immunosorbent assay. Without a promoter, rHuEPO was not absorbed. Sodium glycocholate, sodium caprate, and sodium salicylate in the solution of rHuEPO increased the absorption of rHuEPO. Sodium salicylate or sodium caprate in the suppository with rHuEPO also increased its absorption. The bioavailability of rHuEPO in a suppository containing 5% sodium salicylate compared with that by an intravenous injection was 1.2%. rHuEPO given in rectal suppositories containing sodium salicylate and inserted once a day for 6 consecutive days increased erythropoiesis in peripheral blood.

Administration, Rectal↗
PubMed1987

Possible mechanisms for the enhancement of rectal absorption of hydrophilic drugs and polypeptides by aqueous polyacrylic acid gel.

The mechanisms of absorption enhancing effect by polyacrylic acid gel were investigated in rats. Polyacrylic acid gel significantly enhanced rectal absorption of phenol red, a hydrophilic compound. The enhanced absorption was concentration dependent in the range of 0.01-0.05% w/v polyacrylic acid in gel. The gel also significantly increased the influx and the net influx on water movement in rat rectum. Further, the histological change in rectal epithelium after administration of the polyacrylic acid gel was examined with transmission electron microscopy. The structural changes, which were removal of the mucus and fenestrations of the intercellular spaces 5 and 10 min after administration of polyacrylic acid gel, were observed. These changes were reversible and returned relatively soon to normal levels. Thus, the absorption promoting effect by polyacrylic acid gel may occur mainly with increased water influx as a driving force.

Acrylic Resins↗
PubMed1991

Enhancement effect of lauric acid on the rectal absorption of propranolol from suppository in rats.

In a previous paper, we have demonstrated that medium chain fatty acids significantly enhance the in vitro rectal absorption of propranolol (PL) and that the enhancement may be partly due to the formation of a complex with a fatty acid at a 1:1 molar ratio. To confirm in vivo the enhancement effect of lauric acid on PL absorption, PL suppositories with lauric acid at various molar ratios were administered to rat rectum. PL absorption from Witepsol and macrogol suppositories with lauric acid at a 1:1 molar ratio was much larger than that after PL alone and the 1:2 or 1:3 molar ratio ones. The bioavailability (BA) after administration of the 1:1 molar ratio suppository (PL, 4 mg/kg) was 1.6- and 2.1-fold for the Witepsol and macrogol formulations respectively, compared with that after PL alone. A similar result was obtained with the PL solid dispersion suppository with lauric acid at a 1:1 molar ratio, showing a 1.7-fold higher BA compared with PL alone. The release of PL from the macrogol suppository was significantly faster at a 1:1 molar ratio than that of other preparations, but not so in the solid dispersion suppository. There was not good agreement between the release rates of PL from the suppositories and the plasma levels after dosing. These results supported the concept that a portion of PL, by forming a 1:1 complex with lauric acid, would penetrate across the rectal mucosa more easily than PL alone.

Administration, Rectal↗
PubMed1997

Rectal absorption of ozagrel from a suppository containing its commercial tablet in healthy human subjects.

A suppository containing an ozagrel tablet was prepared using Witepsol H-15 as a base, and its rectal absorption was studied in male human volunteers. In comparison, a commercially available ozagrel tablet was administered orally to all the individuals in a cross-over design. After rectal dosing, ozagrel was absorbed rapidly at a Tmax of 0.75 h, and its elimination half-life was longer than after oral dosing. The extent of absorption of ozagrel after both administration routes was similar. However, the bioavailability of the rectal suppository is 92 +/- 37% (mean +/- S.D.; n = 6) relative to the oral tablet. The tablet-containing suppository is easy to prepare, with its content being accurate and reproducible. Thus, the present study suggests that the rectal administration of an ozagrel suppository is a practical and promising alternative to oral administration, especially for patients who cannot take tablets orally. This study demonstrated for the first time the possibility of an ozagrel suppository in human subjects.

Adult↗
PubMed1988

Rectal absorption enhancement of rate-controlled delivered ampicillin sodium by sodium decanoate in conscious rats.

Because of the relatively poor intestinal absorption of ampicillin sodium, efforts have been made to enhance ampicillin absorption by co-administration of absorption promoters. In the present study the enhancing effect of sodium decanoate on rate and extent of rectal ampicillin absorption in rats has been evaluated after rate-controlled and site-controlled delivery of aqueous solutions. Rectal absorption without enhancer was extremely low (8 +/- 7%), and the addition of 0.032 M sodium decanoate gave comparable values. However, administration in 0.16 M decanoate considerably increased ampicillin bioavailability, to 79 +/- 30%, whereas the absorption rate was not significantly affected.

Administration, Rectal↗
PubMed1986

Thallium scintigraphy in the evaluation of portal systemic shunting. The problem of rectal absorption.

Thallium-201 scintigraphy is an attractive method for studying the portal systemic shunting. However, the technique is sometimes hampered by a low rectal absorption. The present work shows that cirrhotic patients present a significantly lower activity in the regions of interest in relation to the low absorption of the tracer as compared with non-cirrhotic subjects (p less than 0.01). This study also demonstrates that the dilution of the tracer in a large volume cannot be envisaged in order to increase the surface contact and secondarily the absorption, because part of the tracer can reach the inferior vena cava via portal systemic communications in the lower part of the rectum. Oral administration of the thallium was also attempted but this route cannot be used in relation to its poor absorption and due to the difficulty in separating liver from intestinal activity. The study also shows that even in the case of low activity in the regions of interest, the interpretation of the test in cirrhotic patients is usually possible on the condition that the curves of radioactivity in the liver and cardiac areas are ascending. Using these criteria, only 6.7% of the tests were in fact not interpretable in this study.

Female↗
PubMed1978

Rectal absorption of homatropine [14C]methylbromide in the rat.

Homatropine[14C]methylbromide (HMB-14C) was administered to rats by intramuscular injection, oral gavage and rectal suppository. Plasma concentration of 14C were measured over the subsequent 12 h. Peak plasma concentrations were higher and achieved more rapidly after rectal administration than by the other routes whether HMB-14C was administered in a water-soluble suppository base or in aqueous solution. Twelve h after the suppositories were inserted and retained 28% of the 14C had been excreted in the urine while 56% remained in the large intestine. Unlabelled HMB, given in rectal suppositories to anaesthetized rats, caused prompt blockade of the effects of vagal stimulation on pulse rate and of intravenous acetylcholine on blood pressure. These results confirm the rapid rectal absorption of the drug.

Absorption↗
PubMed1978

[Rectal absorption of phenobarbital in children as affected by different vehicles].

68 infants received 7--15 mg phenobarbital and sodium-phenobarbital/kg body weight by suppositories of different melting-points and hydroxyl-values (Witepsol H 12, W 35, E 76). The kinetic analysis of the serum concentration curve shows that the rate of rectal absorption is significantly increased if sodium-phenobarbital instead of phenobarbital is applied. The absorption rate is faster using suppositories with a lower melting-point (32.5 degrees C) compared to suppositories with a higher one (37.5 degrees C). Increasing the amount of hydroxyl values in the vehicle the absorption rate of phenobarbital becomes faster. Comparing the area under the serum concentration curve after intravenous and rectal application in 8 infants the absorption ratio was 74%.

Chemical Phenomena↗
PubMed1998

Human rectal absorption of short- and medium-chain C2-C10 fatty acids.

BACKGROUND: Current knowledge on the colonorectal absorption of medium-chain fatty acids is limited. The purpose of the present study was to evaluate and compare the human rectal absorption of short- and medium-chain C2-C10 fatty acids in healthy volunteers. METHODS: Dialysis bags containing 20 mmol x l(-1) of the fatty acids acetate, butyrate, hexanoate, octanoate, or decanoate in a phosphate-buffered (pH neutral) isoosmotic electrolyte solution were placed in the rectum for 30 min in 14 healthy volunteers. Absorption rates were calculated for all fatty acids, sodium, potassium, and water. RESULTS: Absorption rates of the fatty acids acetate, butyrate, hexanoate, octanoate or decanoate were the same (1.9 +/- 0.1 = 2.5 +/- 0.2 = 1.7 +/- 0.2 = 1.9 +/- 0.2 = 2.2 +/- 0.1 micromol x cm(-2) x h(-1) (mean +/- standard error of the mean), respectively; P = 0.24). CONCLUSIONS: Medium-chain fatty acids were absorbed in the human rectum at a rate similar to that for short-chain fatty acids. If results can be applied to the human colon, colonic absorption of medium-chain fatty acids could possibly become an important secondary site of absorption in abnormal intestinal conditions such as massive small-intestinal resection or malabsorption syndromes.

Administration, Rectal↗
PubMed1985

Topical administration of 5-aminosalicylic acid enemas in patients with ulcerative colitis. Studies on rectal absorption and excretion.

5-aminosalicylic acid (5-ASA) is a new treatment for patients suffering from ulcerative colitis but only limited information is available about its rectal absorption. We therefore studied seven patients with ulcerative colitis in remission, and five with active disease to determine acetylated and free 5-ASA plasma concentrations and urinary acetyl 5-ASA after the administration of three different types of enemas: (2 g 5-ASA/100 ml, 4 g/100 ml, and 200 ml). In patients in remission urinary acetyl 5-ASA excretion was dose and volume dependent (p less than 0.01; p less than 0.05) but this correlation was absent in active disease. Because aminosalicylates are usually eliminated through the kidney, these low values (10% in active disease and 19% in those in remission) suggest that the beneficial action may be local. Urinary recovery was significantly lower in patients with active disease (p less than 0.01; p less than 0.02). No accumulation of 5-ASA was found in plasma after repeated daily administration.

Administration, Topical↗
PubMed1992

Investigations on the rectal absorption of chloramphenicol in rabbits after tenside use.

The rectal dose of 16 mg.kg-1 b.w. chloramphenicol (1) without additional tensides did not result in any detectable absorption of effective substance. In contrast, 0.04% of the N-lauroylleucine tenside allowed a rectal absorption having the same effect as that of an injection of the same quantities of effective substance. The tenside efficiency was not influenced by varied suppository masses (gelatine or Rosupol U, respectively), or by the pH value of the suppositories. Different particle sizes (less than 40 microns or greater than or equal to 40 up to less than 400 microns) of 1 did not change the absorption rate (AUC0-5h) significantly, but did change the plasma concentration-time profile considerably.

Animals↗
PubMed1984

Enhanced rectal absorption of cefmetazole and cefoxitin in the presence of epinephrine metabolites in rats and a high-performance liquid chromatographic assay for cephamycin antibiotics.

4-Hydroxy-3-methoxymandelic acid and 3,4-dihydroxymandelic acid were found to be potent adjuvants for the rectal absorption of water-soluble compounds in rats. Both adjuvants enhanced the absorption of two cephamycin antibiotics, cefmetazole and cefoxitin. Maximum plasma levels of the antibiotics were obtained within 30 min after rectal administration. The bioavailability of both antibiotics appeared to depend on the concentration of the adjuvant in the microenema, the dosage form used in these experiments. Instead of a microbial assay, a new chemical method involving high-performance liquid chromatography with an ion-pairing technique was developed for analyzing the cephamycin antibiotic plasma levels.

Adjuvants, Pharmaceutic↗
PubMed1981

Rectal absorption of some glycosaminoglycan sulphates and heparin in rats.

A standardized extract of glycosaminoglycan sulphates containing heparin, with a low affinity for antithrombin III, and a commercial heparin were administered to rats, by the rectal route. When the glycosaminoglycan sulphates were given in oil emulsion with sodium laurylsarcosinate as surfactant, 1 mg kg-1 and 3 mg kg-1 were sufficient for the clearing and anticoagulant activities, respectively. The rectal absorption of glycosaminoglycans after dosing with a suitable 'promoter' produced dose-dependent effects and their kinetics were comparable to those obtained after intramuscular administration. The oil emulsion improved the bioavailability of glycosaminoglycan sulphates at least 20 times.

Absorption↗
PubMed1994

Effect of sodium salicylate on insulin rectal absorption in humans.

The absorption promoting effect of sodium salicylate (CAS 54-21-7), 200 mg/100-U insulin (CAS 12584-58-6) suppository, was studied in 4 normal volunteers and 15 insulin dependent diabetic patients. Insulin rectal bioavailability was quantitated through the measurement of its hypoglycaemic effect and of its serum levels. A hypoglycaemic effect and a significant rise in serum insulin concentrations were traced at 15 min and maintained for 90 min post administration. The investigated suppositories, thus, proved that sodium salicylate is effective in enhancing the rectal absorption of insulin in humans.

Administration, Rectal↗