Publications by authors named "Muranishi S"

Background: Elderly inpatients who develop fevers after resumption of oral intake are often considered to have aspiration pneumonia (AP) and be tentatively fasted. Fasting has been associated with prolonged hospital stays and decreased swallowing ability. The purpose of this study was to compare AP and other infections after resumption of oral intake in elderly inpatients and to identify the clinical characteristics.

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We synthesized four novel lipophilic derivatives of phenylalanyl-glycine (Phe-Gly), C4-Phe-Gly, Phe-Gly-C4, C6-Phe-Gly and C8-Phe-Gly by chemical modification with butyric acid (C4), caproic acid (C6) and octanoic acid (C8). The effect of the acylation on the stability, permeability and accumulation of Phe-Gly in the intestine was investigated by in vitro studies. The stability of Phe-Gly in homogenates of duodenal and colonic membranes was low, but was significantly improved by the acylation except for Phe-Gly-C4.

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Effects of various viscous vehicles on the pulmonary absorption of water-soluble drugs were examined by an in situ pulmonary absorption experiment. Gelatin, polyvinylacohol (PVA), hydroxypropylcellose (HPC), chondroitin sulfate A sodium salt (CS), polyacrylic acid (PAA), methylcellulose #400 (MC400) and hyaluronic acid sodium salt (HA) were used as models of viscous vehicles. 5(6)-Carboxyfluorescein (CF) and fluorescein isothiocayanate-labeled dextran with an average molecular weight of 4000 (FD4) were used as water-soluble drugs.

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We synthesized three novel lipophilic derivatives of phenylalanyl-glycine (Phe-Gly), C4-Phe-Gly, C6-Phe-Gly and C8-Phe-Gly by chemical modification with butyric acid (C4), caproic acid (C6) and octanoic acid (C8). The effect of the acylation on the stability, permeability and accumulation of Phe-Gly in the skin was investigated by in vitro studies. The stability of Phe-Gly in skin homogenates was low, but was significantly improved by the acylation.

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The objective of this study was to achieve the colon-specific delivery of an anti-ulcerative colitis drug using chitosan capsules and to accelerate healing of 2,4,6-trinitrobenzene sulfonic acid sodium salt (TNBS)-induced colitis in rats. 5-Aminosalicylic acid (5-ASA) was used as a model of an anti-inflammatory drug. The gastrointestinal transit of chitosan capsules was determined by counting the number of capsules in the gastrointestinal lumen by celiotomy at certain times after their oral administration to rats.

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The absorption of water soluble compounds with different molecular weights, such as phenol red (MW 354), trypan blue (MW 960), fluorescein isothiocyanate dextrans, (MW 4400 and 9100) was studied in the lung, nasal cavity, buccal cavity, small and large intestine of rats. For all the compounds, maximal absorption was observed when administered to the lung. The rank order of absorption of each compound from various administration sites was lung>small intestine> or =nasal cavity> or =large intestine> or =buccal cavity.

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The permeability of insulin across Xenopus pulmonary membrane and the effects of various absorption enhancers on insulin permeability were examined using an in vitro Ussing chamber technique. Absorption enhancers used in this study were sodium caprate (NaCap), sodium glycocholate (NaGC), sodium salicylate (NaSal) and ethylenediaminetetraacetic acid disodium salt (EDTA). The permeability of insulin across Xenopus pulmonary membrane significantly increased in the presence of NaCap and NaGC, while EDTA and NaSal did not enhance the permeability.

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Purpose: The objective of this study is to examine the intestinal permeability of novel lipophilic derivatives of DADLE (Tyr-D-Ala-Gly-Phe-D-Leu), an enkephalin analogue, using isolated rat intestinal membranes.

Methods: The novel lipophilic derivatives of DADLE were synthesized by chemical modification with various fatty acids at the C terminus. The pharmacological activities of these DADLE derivatives were assessed by a hot plate test.

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The objective of this study was to estimate colon-specific delivery of insulin and (Asu(1,7))eel-calcitonin using novel azopolymer-coated pellets. In vitro drug-release experiments from the azopolymer-coated pellets containing fluorescein isothiocyanate dextran (MW 4400; FD-4) were carried out by the Japanese Pharmacopoeia (J.P.

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We have examined the in-vitro permeability characteristics of insulin in the presence of various absorption enhancers across rat intestinal membranes and have assessed the intestinal toxicity of the enhancers using an in-vitro Ussing chamber method. The absorption enhancing mechanism of n-lauryl-beta-D-maltopyranoside was studied also. The permeability of insulin across the intestinal membranes was low in the absence of absorption enhancers.

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A pharmacokinetic model of colon-specific drug delivery developed in a previous study has been validated by use of 5-aminosalicylic acid (5-ASA) as a model anti-inflammatory drug. The simulation curves obtained from the pharmacokinetic model were in good agreement with experimental data obtained after oral administration of 5-ASA-containing chitosan capsules. The concentrations of 5-ASA in the large intestinal mucosa after drug administration were higher than after administration of the drug in carmellose suspension.

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Bacitracin is an antibacterial cyclic dodecapeptide produced by Bacillus licheniformin. Besides antibacterial activity, it is reported to have a protease inhibitory activity and an absorption enhancing action. Here we determined the effects of bacitracin on transport of water-soluble dye fluoresceinisothiocyanate (FITC)-dextran across the rat intestinal mucosal membrane using an electrophysiological technique.

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The effects of formulation factors on the enhancement of colonic absorption of azetirelin by n-lauryl-beta-maltopyranoside (LM) were studied in rats. Coadministration of LM with a small volume of azetirelin solution to the proximal colon increased the AUC of the drug by 8.7-fold.

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The objective of this study was to achieve colon-specific delivery of budesonide using azopolymer-coated pellets and to accelerate healing of 2,4,6-trinitrobenzenesulphonic acid sodium salt (TNBS)-induced colitis in rats. After oral administration of azopolymer-coated pellets containing budesonide, a significant increase was observed in the therapeutic effects of the drug accompanied by a decrease in its systemic adverse effects when compared with oral administration in saline or rectal administration by enema. In addition, with the use of the colon-specific oral dosage form the dose of budesonide could be reduced.

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The objective of this study was to estimate the therapeutic effects of R68070, a new thromboxane synthase inhibitor, on 2,4,6-trinitrobenzenesulfonic acid sodium salt (TNBS)-induced ulcerative colitis in rats. We also examined the acceleration of the healing effect of R68070 with chitosan capsules to achieve its colon-specific delivery. The colonic injury and inflammation were assessed by measuring the myeloperoxidase (MPO) activities, colon wet weight/body weight (C/B) ratio and the damage score, respectively.

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Purpose: Three types of acyl tetragastrin (TG), acetyl-TG (C2-TG), butyryl-TG (C4-TG) and caproyl-TG (C6-TG) were synthesized and their in vitro intestinal permeability characteristics were examined using Caco-2 monolayers.

Methods: The disappearance of acyl-TGs from the apical side of Caco-2 monolayers was estimated by analyzing degradation and permeation processes in terms of clearance.

Results: The amount of native TG transported to the basolateral side was very low due to its large degradation clearance (CLd) on the apical side.

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The objective of this study was to examine the effects of protease inhibitors on the absorption of calcitonin from different regions of the intestine in rats. The absorption experiments were investigated by in-situ use of closed intestinal loops in rats and stability of calcitonin was examined in mucosal homogenates and intestinal fluids. The intestinal absorption of calcitonin was evaluated by measurement of its hypocalcaemic effect.

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We studied the enhancing and toxic effects of five different absorption enhancers on the transport of FITC-dextran with an average molecular weight of 4000 (FD-4) across Caco-2 cell monolayers, and their enhancing effects were also compared with those in rat intestine. The enhancing and cytotoxic properties of these enhancers were characterized using the following tests: measurement of the permeability coefficients of FD-4 and the transepithelial electrical resistance (TEER) in Caco-2, the release of cytosolic lactate dehydrogenase (LDH) and intracellular mitochondrial dehydrogenase (MDH) activity. All the absorption enhancers increased the permeability of FD-4 across Caco-2 cell monolayers and a good relationship was observed between the enhancement and their toxic effects.

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The delivery formulation 5-FU-MS [5-fluorouracil (5-FU) incorporated in microspheres composed of a poly(glycolide-co-lactide) matrix] slowly releases 5-FU over 3 weeks. 5-FU-MS delivers higher concentrations of the drug to the i.p.

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Oral bioavailability of biologically active peptides and proteins is generally very low because they are extensively degraded by peptidases and proteases in the gastrointestinal tract and impermeable through the intestinal mucosal membrane. Consequently, although clinical application of peptide drugs is limited to administration by injection, such frequent subjects the patients to considerable pain, and there is also possibility of the manifestation of serious side effects. Therefore various approaches have been examined to overcome the delivery problems of peptide drugs.

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The effects of various protease inhibitors on the stability of leucine enkephalin (Leu-Enk) and [D-Ala2,D-Leu5] enkephalin (DADLE) were investigated, and the permeability of these peptides was also examined in an in vitro Ussing chamber. Captopril, thiorphan, bacitracin, bestatin, puromycin, amastatin, and sodium glycocholate (Na-GC) were chosen as protease inhibitors. Regional differences in the stability of Leu-Enk and DADLE were observed, and the rank order of the stability of these peptides was colon > duodenum > ileum > jejunum.

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The permeation of ebiratide (H-Met(O2)-Glu-His-Phe-D-Lys-Phe-NH(CH2)8NH2), a novel ACTH analogue, across the intestinal mucosae has been examined by use of isolated intestinal membranes from rats in a modified Ussing chamber. Regional differences were observed in the permeation of ebiratide across intestinal membranes; the order of membrane permeability was jejunum > ileum > duodenum > colon. Overall, the permeation of ebiratide was relatively poor.

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The effects of absorption enhancers on the pulmonary absorption of (Asu1,7)-eel calcitonin (ECT) and their pulmonary toxicity were examined by means of in situ pulmonary experiments. The absorption of ECT from the lungs was estimated by its hypocalcemic effect. The pulmonary membrane toxicity of absorption enhancers was evaluated by the leakage of Evans Blue from the plasma into the lungs.

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