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Yoshiaki Kawashima - One of the best experts on this subject based on the ideXlab platform.

  • novel Mucoadhesion tests for polymers and polymer coated particles to design optimal mucoadhesive drug delivery systems
    Advanced Drug Delivery Reviews, 2005
    Co-Authors: Hirofumi Takeuchi, Hiromitsu Yamamoto, Jringjai Thongborisute, Yuji Matsui, Hikaru Sugihara, Yoshiaki Kawashima
    Abstract:

    To design an effective particulate drug delivery system having mucoadhesive function, several Mucoadhesion tests for polymers and the resultant particulate systems were developed. Mucin particle method is a simple Mucoadhesion test for polymers, in which the commercial mucin particles are used. By measuring the change in particle size or zeta potential of the mucin particle in a certain concentration of polymer solution, we could estimate the extent of their mucoadhesive property. BIACORE method is also a novel Mucoadhesion test for polymers. On passing through the mucin suspension on the polymer-immobilized chip of BIACORE instrument, the interaction was quantitatively evaluated with the change in its response diagram. By using these Mucoadhesion tests, we detected a strong mucoadhesive property of several types of chitosan and Carbopol. Evaluation of mucoadhesive property of polymer-coated particulate systems was demonstrated with the particle counting method developed by us. To detect the mucoadhesive phenomena in the intestinal tract, we observed the rat intestine with the confocal laser scanning microscope (CLSM) after oral administration of the particulate systems. The resultant photographs clearly showed a longer retention of submicron-sized chitosan-coated liposomes (ssCS-Lip) in the intestinal tract than other liposomal particles tested such as non-coated liposomes and chitosan-coated multilamellar one. These observations explained well the superiority of the ssCS-Lip as drug carrier in oral administration of calcitonin in rats than other liposomal particles.

  • mucoadhesive dl lactide glycolide copolymer nanospheres coated with chitosan to improve oral delivery of elcatonin
    Pharmaceutical Development and Technology, 2000
    Co-Authors: Yoshiaki Kawashima, Hirofumi Takeuchi, Hiromitsu Yamamoto, Yoshio Kuno
    Abstract:

    The purpose of this work was to develop a novel mucoadhesive DL-lactide/glycolide copolymer (PLGA) nanosphere system to improve peptide absorption and prolong the physiological activity following oral administration. The desired PLGA nanospheres with elcatonin were prepared by the emulsion solvent diffusion method to coat the surface of the resultant nanospheres with a mucoadhesive polymer such as chitosan, poly(acrylic acid), and sodium alginate. Their mucoadhesive properties were evaluated by measuring the nanospheres adsorbed to a rat everted intestinal sac (in vitro). The chitosan-coated nanospheres showed higher Mucoadhesion to the everted intestinal tract in saline than the other polymer-coated nanospheres. There was no Mucoadhesion site-specificity of the chitosan-coated nanospheres between duodenal, jejunal, and ileal sacs. The payload of drug in the chitosan-coated nanospheres was successfully increased by using the solvent diffusion method in oil. The pattern of drug release of the resultant nanospheres did not differ markedly from that of uncoated nanospheres. The chitosan-coated nanospheres with elcatonin were administered intragastrically to fasted Wistar rats. The chitosan-coated nanosphere reduced significantly the blood calcium level compared with elcatonin solution and uncoated nanospheres, and the reduced calcium level was sustained for a period of 48 hr. Even under nonfasting conditions, the Mucoadhesion of chitosan-coated nanospheres was unaltered and the reduction in blood Ca levels was maintained satisfactorily.

  • mucoadhesive dl lactide glycolide copolymer nanospheres coated with chitosan to improve oral delivery of elcatonin
    Pharmaceutical Development and Technology, 2000
    Co-Authors: Yoshiaki Kawashima, Hirofumi Takeuchi, Hiromitsu Yamamoto, Yoshio Kuno
    Abstract:

    The purpose of this work was to develop a novel mucoadhesive DL-lactide/glycolide copolymer (PLGA) nanosphere system to improve peptide absorption and prolong the physiological activity following oral administration. The desired PLGA nanospheres with elcatonin were prepared by the emulsion solvent diffusion method to coat the surface of the resultant nanospheres with a mucoadhesive polymer such as chitosan, poly(acrylic acid), and sodium alginate. Their mucoadhesive properties were evaluated by measuring the nanospheres adsorbed to a rat everted intestinal sac (in vitro). The chitosan-coated nanospheres showed higher Mucoadhesion to the everted intestinal tract in saline than the other polymer-coated nanospheres. There was no Mucoadhesion site-specificity of the chitosan-coated nanospheres between duodenal, jejunal, and ileal sacs. The payload of drug in the chitosan-coated nanospheres was successfully increased by using the solvent diffusion method in oil. The pattern of drug release of the resultant nan...

Hirofumi Takeuchi - One of the best experts on this subject based on the ideXlab platform.

  • novel Mucoadhesion tests for polymers and polymer coated particles to design optimal mucoadhesive drug delivery systems
    Advanced Drug Delivery Reviews, 2005
    Co-Authors: Hirofumi Takeuchi, Hiromitsu Yamamoto, Jringjai Thongborisute, Yuji Matsui, Hikaru Sugihara, Yoshiaki Kawashima
    Abstract:

    To design an effective particulate drug delivery system having mucoadhesive function, several Mucoadhesion tests for polymers and the resultant particulate systems were developed. Mucin particle method is a simple Mucoadhesion test for polymers, in which the commercial mucin particles are used. By measuring the change in particle size or zeta potential of the mucin particle in a certain concentration of polymer solution, we could estimate the extent of their mucoadhesive property. BIACORE method is also a novel Mucoadhesion test for polymers. On passing through the mucin suspension on the polymer-immobilized chip of BIACORE instrument, the interaction was quantitatively evaluated with the change in its response diagram. By using these Mucoadhesion tests, we detected a strong mucoadhesive property of several types of chitosan and Carbopol. Evaluation of mucoadhesive property of polymer-coated particulate systems was demonstrated with the particle counting method developed by us. To detect the mucoadhesive phenomena in the intestinal tract, we observed the rat intestine with the confocal laser scanning microscope (CLSM) after oral administration of the particulate systems. The resultant photographs clearly showed a longer retention of submicron-sized chitosan-coated liposomes (ssCS-Lip) in the intestinal tract than other liposomal particles tested such as non-coated liposomes and chitosan-coated multilamellar one. These observations explained well the superiority of the ssCS-Lip as drug carrier in oral administration of calcitonin in rats than other liposomal particles.

  • mucoadhesive dl lactide glycolide copolymer nanospheres coated with chitosan to improve oral delivery of elcatonin
    Pharmaceutical Development and Technology, 2000
    Co-Authors: Yoshiaki Kawashima, Hirofumi Takeuchi, Hiromitsu Yamamoto, Yoshio Kuno
    Abstract:

    The purpose of this work was to develop a novel mucoadhesive DL-lactide/glycolide copolymer (PLGA) nanosphere system to improve peptide absorption and prolong the physiological activity following oral administration. The desired PLGA nanospheres with elcatonin were prepared by the emulsion solvent diffusion method to coat the surface of the resultant nanospheres with a mucoadhesive polymer such as chitosan, poly(acrylic acid), and sodium alginate. Their mucoadhesive properties were evaluated by measuring the nanospheres adsorbed to a rat everted intestinal sac (in vitro). The chitosan-coated nanospheres showed higher Mucoadhesion to the everted intestinal tract in saline than the other polymer-coated nanospheres. There was no Mucoadhesion site-specificity of the chitosan-coated nanospheres between duodenal, jejunal, and ileal sacs. The payload of drug in the chitosan-coated nanospheres was successfully increased by using the solvent diffusion method in oil. The pattern of drug release of the resultant nanospheres did not differ markedly from that of uncoated nanospheres. The chitosan-coated nanospheres with elcatonin were administered intragastrically to fasted Wistar rats. The chitosan-coated nanosphere reduced significantly the blood calcium level compared with elcatonin solution and uncoated nanospheres, and the reduced calcium level was sustained for a period of 48 hr. Even under nonfasting conditions, the Mucoadhesion of chitosan-coated nanospheres was unaltered and the reduction in blood Ca levels was maintained satisfactorily.

  • mucoadhesive dl lactide glycolide copolymer nanospheres coated with chitosan to improve oral delivery of elcatonin
    Pharmaceutical Development and Technology, 2000
    Co-Authors: Yoshiaki Kawashima, Hirofumi Takeuchi, Hiromitsu Yamamoto, Yoshio Kuno
    Abstract:

    The purpose of this work was to develop a novel mucoadhesive DL-lactide/glycolide copolymer (PLGA) nanosphere system to improve peptide absorption and prolong the physiological activity following oral administration. The desired PLGA nanospheres with elcatonin were prepared by the emulsion solvent diffusion method to coat the surface of the resultant nanospheres with a mucoadhesive polymer such as chitosan, poly(acrylic acid), and sodium alginate. Their mucoadhesive properties were evaluated by measuring the nanospheres adsorbed to a rat everted intestinal sac (in vitro). The chitosan-coated nanospheres showed higher Mucoadhesion to the everted intestinal tract in saline than the other polymer-coated nanospheres. There was no Mucoadhesion site-specificity of the chitosan-coated nanospheres between duodenal, jejunal, and ileal sacs. The payload of drug in the chitosan-coated nanospheres was successfully increased by using the solvent diffusion method in oil. The pattern of drug release of the resultant nan...

Hiromitsu Yamamoto - One of the best experts on this subject based on the ideXlab platform.

  • novel Mucoadhesion tests for polymers and polymer coated particles to design optimal mucoadhesive drug delivery systems
    Advanced Drug Delivery Reviews, 2005
    Co-Authors: Hirofumi Takeuchi, Hiromitsu Yamamoto, Jringjai Thongborisute, Yuji Matsui, Hikaru Sugihara, Yoshiaki Kawashima
    Abstract:

    To design an effective particulate drug delivery system having mucoadhesive function, several Mucoadhesion tests for polymers and the resultant particulate systems were developed. Mucin particle method is a simple Mucoadhesion test for polymers, in which the commercial mucin particles are used. By measuring the change in particle size or zeta potential of the mucin particle in a certain concentration of polymer solution, we could estimate the extent of their mucoadhesive property. BIACORE method is also a novel Mucoadhesion test for polymers. On passing through the mucin suspension on the polymer-immobilized chip of BIACORE instrument, the interaction was quantitatively evaluated with the change in its response diagram. By using these Mucoadhesion tests, we detected a strong mucoadhesive property of several types of chitosan and Carbopol. Evaluation of mucoadhesive property of polymer-coated particulate systems was demonstrated with the particle counting method developed by us. To detect the mucoadhesive phenomena in the intestinal tract, we observed the rat intestine with the confocal laser scanning microscope (CLSM) after oral administration of the particulate systems. The resultant photographs clearly showed a longer retention of submicron-sized chitosan-coated liposomes (ssCS-Lip) in the intestinal tract than other liposomal particles tested such as non-coated liposomes and chitosan-coated multilamellar one. These observations explained well the superiority of the ssCS-Lip as drug carrier in oral administration of calcitonin in rats than other liposomal particles.

  • mucoadhesive dl lactide glycolide copolymer nanospheres coated with chitosan to improve oral delivery of elcatonin
    Pharmaceutical Development and Technology, 2000
    Co-Authors: Yoshiaki Kawashima, Hirofumi Takeuchi, Hiromitsu Yamamoto, Yoshio Kuno
    Abstract:

    The purpose of this work was to develop a novel mucoadhesive DL-lactide/glycolide copolymer (PLGA) nanosphere system to improve peptide absorption and prolong the physiological activity following oral administration. The desired PLGA nanospheres with elcatonin were prepared by the emulsion solvent diffusion method to coat the surface of the resultant nanospheres with a mucoadhesive polymer such as chitosan, poly(acrylic acid), and sodium alginate. Their mucoadhesive properties were evaluated by measuring the nanospheres adsorbed to a rat everted intestinal sac (in vitro). The chitosan-coated nanospheres showed higher Mucoadhesion to the everted intestinal tract in saline than the other polymer-coated nanospheres. There was no Mucoadhesion site-specificity of the chitosan-coated nanospheres between duodenal, jejunal, and ileal sacs. The payload of drug in the chitosan-coated nanospheres was successfully increased by using the solvent diffusion method in oil. The pattern of drug release of the resultant nanospheres did not differ markedly from that of uncoated nanospheres. The chitosan-coated nanospheres with elcatonin were administered intragastrically to fasted Wistar rats. The chitosan-coated nanosphere reduced significantly the blood calcium level compared with elcatonin solution and uncoated nanospheres, and the reduced calcium level was sustained for a period of 48 hr. Even under nonfasting conditions, the Mucoadhesion of chitosan-coated nanospheres was unaltered and the reduction in blood Ca levels was maintained satisfactorily.

  • mucoadhesive dl lactide glycolide copolymer nanospheres coated with chitosan to improve oral delivery of elcatonin
    Pharmaceutical Development and Technology, 2000
    Co-Authors: Yoshiaki Kawashima, Hirofumi Takeuchi, Hiromitsu Yamamoto, Yoshio Kuno
    Abstract:

    The purpose of this work was to develop a novel mucoadhesive DL-lactide/glycolide copolymer (PLGA) nanosphere system to improve peptide absorption and prolong the physiological activity following oral administration. The desired PLGA nanospheres with elcatonin were prepared by the emulsion solvent diffusion method to coat the surface of the resultant nanospheres with a mucoadhesive polymer such as chitosan, poly(acrylic acid), and sodium alginate. Their mucoadhesive properties were evaluated by measuring the nanospheres adsorbed to a rat everted intestinal sac (in vitro). The chitosan-coated nanospheres showed higher Mucoadhesion to the everted intestinal tract in saline than the other polymer-coated nanospheres. There was no Mucoadhesion site-specificity of the chitosan-coated nanospheres between duodenal, jejunal, and ileal sacs. The payload of drug in the chitosan-coated nanospheres was successfully increased by using the solvent diffusion method in oil. The pattern of drug release of the resultant nan...

Gilles Ponchel - One of the best experts on this subject based on the ideXlab platform.

  • Mucoadhesion mechanism of chitosan and thiolated chitosan poly isobutyl cyanoacrylate core shell nanoparticles
    Biomaterials, 2007
    Co-Authors: Irene Bravoosuna, Christine Vauthier, Alessandra Farabollini, Giovanni Filippo Palmieri, Gilles Ponchel
    Abstract:

    The study is focused on the evaluation of the potential bioadhesive behaviour of chitosan and thiolated chitosan (chitosan-TBA)-coated poly(isobutyl cyanoacrylates) (PIBCA) nanoparticles. Nanoparticles were obtained by radical emulsion polymerisation with chitosan of different molecular weight and with different proportions of chitosan/chitosan-TBA. Mucoadhesion was ex vivo evaluated under static conditions by applying nanoparticle suspensions on rat intestinal mucosal surfaces and evaluating the amount of nanoparticles remaining attached to the mucosa after incubation. The analysis of the results obtained demonstrated that the presence of either chitosan or thiolated chitosan on the PIBCA nanoparticle surface clearly enhanced the Mucoadhesion behaviour thanks to non-covalent interactions (ionic interaction and hydrogen bonds) with mucus chains. Both, the molecular weight of chitosan and the proportion of chitosan-TBA in the formulation influenced the nanoparticle hydrodynamic diameter and hence their transport through the mucus layer. Improved interpenetration ability with the mucus chain during the attachment process was suggested for the chitosan of high molecular weight, enhancing the bioadhesiveness of the system. The presence of thiol groups on the nanoparticle surface at high concentration (200 x 10(-6) micromol SH/cm2) increased the Mucoadhesion capacity of nanoparticles by forming covalent bonds with the cysteine residues of the mucus glycoproteins.

  • Mucoadhesion of colloidal particulate systems in the gastro intestinal tract
    European Journal of Pharmaceutics and Biopharmaceutics, 1997
    Co-Authors: Gilles Ponchel, Mariejeanne Montisci, Assia Dembri, Carlo Durrer, Dominique Duchene
    Abstract:

    The oral route is the preferred route for drug delivery. However, numerous drugs remain poorly available when administered by this route. In order to circumvent this problem, it has been proposed, successfully for several of them, to associate drugs with colloidal polymeric particle systems. Orally administered nano- and microparticles can follow at least three different pathways: (i) capture by gut-associated lymphoid tissue; (ii) Mucoadhesion; and (iii) direct faecal elimination. The relative importance of these different mechanisms is discussed. Emphasis has been laid on Mucoadhesion which has been assessed in vitro and in vivo by using polystyrene and poly(lactic acid) nanoparticles as models. On the one hand, in vitro adsorption and desorption studies have shown that particles could be captured to a considerable extent by the mucous gel layer lining the gastro-intestinal tract through a Mucoadhesion mechanism. On the other hand, the in vivo behaviour of the particles in the intestinal lumen has been accurately investigated by means of radiolabelled particles. Direct particle translocation through the intestinal mucosa was not predominant. On the contrary, a significant fraction of the particles was captured by the mucous gel layer while the remainder of the particles underwent unmodified transit. It can be concluded that the therapeutic potential of colloidal drug carriers after oral administration is probably not to deliver the drug directly into the blood flow but to increase bioavailability by protecting the drug from denaturation in the gastro-intestinal lumen, or by increasing the drug concentration for a prolonged period of time directly at the surface of the mucous membrane.

Yoshio Kuno - One of the best experts on this subject based on the ideXlab platform.

  • mucoadhesive dl lactide glycolide copolymer nanospheres coated with chitosan to improve oral delivery of elcatonin
    Pharmaceutical Development and Technology, 2000
    Co-Authors: Yoshiaki Kawashima, Hirofumi Takeuchi, Hiromitsu Yamamoto, Yoshio Kuno
    Abstract:

    The purpose of this work was to develop a novel mucoadhesive DL-lactide/glycolide copolymer (PLGA) nanosphere system to improve peptide absorption and prolong the physiological activity following oral administration. The desired PLGA nanospheres with elcatonin were prepared by the emulsion solvent diffusion method to coat the surface of the resultant nanospheres with a mucoadhesive polymer such as chitosan, poly(acrylic acid), and sodium alginate. Their mucoadhesive properties were evaluated by measuring the nanospheres adsorbed to a rat everted intestinal sac (in vitro). The chitosan-coated nanospheres showed higher Mucoadhesion to the everted intestinal tract in saline than the other polymer-coated nanospheres. There was no Mucoadhesion site-specificity of the chitosan-coated nanospheres between duodenal, jejunal, and ileal sacs. The payload of drug in the chitosan-coated nanospheres was successfully increased by using the solvent diffusion method in oil. The pattern of drug release of the resultant nanospheres did not differ markedly from that of uncoated nanospheres. The chitosan-coated nanospheres with elcatonin were administered intragastrically to fasted Wistar rats. The chitosan-coated nanosphere reduced significantly the blood calcium level compared with elcatonin solution and uncoated nanospheres, and the reduced calcium level was sustained for a period of 48 hr. Even under nonfasting conditions, the Mucoadhesion of chitosan-coated nanospheres was unaltered and the reduction in blood Ca levels was maintained satisfactorily.

  • mucoadhesive dl lactide glycolide copolymer nanospheres coated with chitosan to improve oral delivery of elcatonin
    Pharmaceutical Development and Technology, 2000
    Co-Authors: Yoshiaki Kawashima, Hirofumi Takeuchi, Hiromitsu Yamamoto, Yoshio Kuno
    Abstract:

    The purpose of this work was to develop a novel mucoadhesive DL-lactide/glycolide copolymer (PLGA) nanosphere system to improve peptide absorption and prolong the physiological activity following oral administration. The desired PLGA nanospheres with elcatonin were prepared by the emulsion solvent diffusion method to coat the surface of the resultant nanospheres with a mucoadhesive polymer such as chitosan, poly(acrylic acid), and sodium alginate. Their mucoadhesive properties were evaluated by measuring the nanospheres adsorbed to a rat everted intestinal sac (in vitro). The chitosan-coated nanospheres showed higher Mucoadhesion to the everted intestinal tract in saline than the other polymer-coated nanospheres. There was no Mucoadhesion site-specificity of the chitosan-coated nanospheres between duodenal, jejunal, and ileal sacs. The payload of drug in the chitosan-coated nanospheres was successfully increased by using the solvent diffusion method in oil. The pattern of drug release of the resultant nan...