The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform

H E Junginger - One of the best experts on this subject based on the ideXlab platform.

  • recent advances in Buccal drug delivery and absorption in vitro and in vivo studies
    Journal of Controlled Release, 1999
    Co-Authors: H E Junginger, Janet A Hoogstraate, Coos J Verhoef
    Abstract:

    Abstract In the first part of this study, the aim was to characterize transport of fluorescein isothiocyanate (FITC)-labelled dextrans of different molecular weights as model compounds for peptides and proteins through Buccal mucosa. The penetration of these dextrans through porcine Buccal mucosa (a nonkeratinized epithelium, comparable to human Buccal mucosa) was investigated by measuring transBuccal fluxes and by analyzing the distribution of the fluorescent probe in the epithelium, using confocal laser scanning microscopy for visualizing permeation pathways. The results revealed that passage of hydrophilic compounds such as the FITC–dextrans through porcine Buccal epithelium is restricted to permeants with a molecular weight lower than 20 kDa. The permeabilities of Buccal mucosa for the 4 and 10 kDa FITC–dextran (of the order of 10 −8 cm/s) were not significantly different from each other or from the much smaller compound FITC. The confocal images of the distribution pattern of FITC–dextrans showed that the paracellular route is the major pathway through Buccal epithelium. In the in vivo part of this study, Buccal delivery of FITC-labelled dextran 4400 (FD4) and the peptide drug buserelin was investigated in vivo, in pigs. The delivery device consisted of an application chamber with a solution of FD4 or buserelin, and was attached to the Buccal mucosa for 4 h using an adhesive patch. A randomized cross-over study including intravenous administration and Buccal delivery without and with 10 mM sodium glycodeoxycholate (GDC) as an absorption enhancer was performed in pigs. After Buccal administration, steady-state plasma levels were rapidly achieved. Co-administration of 10 mM GDC increased the absolute bioavailability from 1.8±0.5 to 12.7±2.0% for FD4. From the present studies, it is concluded that Buccal administration is a suitable route for the delivery for macromolecules and hydrophilic compounds such as peptide drugs.

  • in vivo Buccal delivery of the peptide drug buserelin with glycodeoxycholate as an absorption enhancer in pigs
    Pharmaceutical Research, 1996
    Co-Authors: Janet A Hoogstraate, Coos J Verhoef, A Pijpers, Leo Van Leengoed, J H M Verheijden, H E Junginger, H E Bodde
    Abstract:

    Purpose. To study the potential of Buccal delivery of the peptide drug in pigs. Methods. Intravenous administration and Buccal delivery without and with 10 mM sodium glycodeoxycholate (GDC) as absorption enhancer were investigated as a randomised cross-over study in six pigs. The Buccal delivery device consisted of an application chamber with a solution of buserelin and was attached to the Buccal mucosa for 4 hours using an adhesive patch. Results. Buccal administration of buserelin resulted in rapidly reached steady state plasma levels. The absolute bioavailability of the peptide after Buccal delivery for 4 hours could be increased from 1.0 ± 0.3 to 5.3 ± 1.1% (mean ± S.D.) by co-administration of 10 mM GDC (0.45% w/v)). Conclusions. The results of this study demonstrate that Buccal administration with the use of absorption enhancers is a useful approach for the delivery of peptide drugs such as buserelin.

  • Buccal delivery of fluorescein isothiocyanate dextran 4400 and the peptide drug buserelin with glycodeoxycholate as an absorption enhancer in pigs
    Journal of Controlled Release, 1996
    Co-Authors: A J Hoogstraate, A Pijpers, Leo Van Leengoed, J H M Verheijden, H E Junginger, J C Verhoef, H E Bodde
    Abstract:

    Delivery of drugs via the Buccal mucosa is an alternative for the low oral absorption and inconvenient parenteral administration of hydrophilic macromolecular drugs. Due to the low permeability of the Buccal epithelium the use of absorption enhancers is a prerequisite. In this study, Buccal delivery of fluorescein isothiocyanate-labelled dextran 4400 (FD4) and the peptide drug buserelin was investigated in vivo, in pigs. The delivery device consisted of an application chamber with a solution of FD4 or buserelin, and was attached to the Buccal mucosa for 4 h using an adhesive patch. A randomized cross-over study including intravenous administration and Buccal delivery without and with 10 mM sodium glycodeoxycholate (GDC) as absorption enhancer was performed in pigs. After Buccal administration steady-state plasma levels were rapidly achieved. Co-administration of 10 mM GDC increased the absolute bioavailability from 1.8 ± 0.5% to 12.7 ± 2.0% for FD4, and from 1.0 ± 0.3% to 5.3 ± 1.1% for buserelin. From the present studies it is concluded that Buccal administration is a suitable route of delivery for macromolecules and hydrophilic compounds such as peptide drugs.

  • in vivo Buccal delivery of fluorescein isothiocyanate dextran 4400 with glycodeoxycholate as an absorption enhancer in pigs
    Journal of Pharmaceutical Sciences, 1996
    Co-Authors: A J Hoogstraate, A Pijpers, Leo Van Leengoed, J H M Verheijden, H E Junginger, J C Verhoef, H E Bodde
    Abstract:

    Buccal delivery of fluorescein isothiocyanate labeled dextran 4400 (FD4) was investigated in-vivo in pigs. The delivery device consisted of an application chamber with a solution of FD4 and was adhered to the Buccal mucosa for 4 h using an adhesive patch. A randomized crossover study including intravenous administration and Buccal delivery without and with 10 mM sodium glycodeoxycholate (GDC) as absorption enhancer was performed in five pigs. After Buccal administration, steady state plasma levels were rapidly reached. Coadministration of 10 mM GDC increased the absolute bioavailability of FD4 from 1.8 ± 0.5% to 12.7 ± 2.0%. Since FD4 is a macromolecular and hydrophilic compound such as peptide and protein drugs, Buccal delivery would provide an adequate alternative to the parenteral administration of these drugs.

  • diffusion rates and transport pathways of fluorescein isothiocyanate fitc labeled model compounds through Buccal epithelium
    Pharmaceutical Research, 1994
    Co-Authors: Janet A Hoogstraate, Coos J Verhoef, H E Junginger, Christopher Cullander, Fred J Nagelkerke, S Senel, H E Bodde
    Abstract:

    The aim of this study was to characterize transport of FITC-labeled dextrans of different molecular weights as model compounds for peptides and proteins through Buccal mucosa. The penetration of these dextrans through porcine Buccal mucosa (a nonkeratinized epithelium, comparable to human Buccal mucosa) was investigated by measuring transBuccal fluxes and by analyzing the distribution of the fluorescent probe in the epithelium, using confocal laser scanning microscopy for visualizing permeation pathways. The results revealed that passage of porcine Buccal epithelium by hydrophilic compounds such as the FITC-dextrans is restricted to permeants with a molecular weight lower than 20 kDa. The permeabilities of Buccal mucosa for the 4- and 10-kDa FITC-dextran (of the order of 10−8 cm/sec) were not significantly different from each other or from the much smaller compound FITC. The confocal images of the distribution pattern of FITC-dextrans showed that the paracellular route is the major pathway through Buccal epithelium.

H E Bodde - One of the best experts on this subject based on the ideXlab platform.

  • in vivo Buccal delivery of the peptide drug buserelin with glycodeoxycholate as an absorption enhancer in pigs
    Pharmaceutical Research, 1996
    Co-Authors: Janet A Hoogstraate, Coos J Verhoef, A Pijpers, Leo Van Leengoed, J H M Verheijden, H E Junginger, H E Bodde
    Abstract:

    Purpose. To study the potential of Buccal delivery of the peptide drug in pigs. Methods. Intravenous administration and Buccal delivery without and with 10 mM sodium glycodeoxycholate (GDC) as absorption enhancer were investigated as a randomised cross-over study in six pigs. The Buccal delivery device consisted of an application chamber with a solution of buserelin and was attached to the Buccal mucosa for 4 hours using an adhesive patch. Results. Buccal administration of buserelin resulted in rapidly reached steady state plasma levels. The absolute bioavailability of the peptide after Buccal delivery for 4 hours could be increased from 1.0 ± 0.3 to 5.3 ± 1.1% (mean ± S.D.) by co-administration of 10 mM GDC (0.45% w/v)). Conclusions. The results of this study demonstrate that Buccal administration with the use of absorption enhancers is a useful approach for the delivery of peptide drugs such as buserelin.

  • Buccal delivery of fluorescein isothiocyanate dextran 4400 and the peptide drug buserelin with glycodeoxycholate as an absorption enhancer in pigs
    Journal of Controlled Release, 1996
    Co-Authors: A J Hoogstraate, A Pijpers, Leo Van Leengoed, J H M Verheijden, H E Junginger, J C Verhoef, H E Bodde
    Abstract:

    Delivery of drugs via the Buccal mucosa is an alternative for the low oral absorption and inconvenient parenteral administration of hydrophilic macromolecular drugs. Due to the low permeability of the Buccal epithelium the use of absorption enhancers is a prerequisite. In this study, Buccal delivery of fluorescein isothiocyanate-labelled dextran 4400 (FD4) and the peptide drug buserelin was investigated in vivo, in pigs. The delivery device consisted of an application chamber with a solution of FD4 or buserelin, and was attached to the Buccal mucosa for 4 h using an adhesive patch. A randomized cross-over study including intravenous administration and Buccal delivery without and with 10 mM sodium glycodeoxycholate (GDC) as absorption enhancer was performed in pigs. After Buccal administration steady-state plasma levels were rapidly achieved. Co-administration of 10 mM GDC increased the absolute bioavailability from 1.8 ± 0.5% to 12.7 ± 2.0% for FD4, and from 1.0 ± 0.3% to 5.3 ± 1.1% for buserelin. From the present studies it is concluded that Buccal administration is a suitable route of delivery for macromolecules and hydrophilic compounds such as peptide drugs.

  • in vivo Buccal delivery of fluorescein isothiocyanate dextran 4400 with glycodeoxycholate as an absorption enhancer in pigs
    Journal of Pharmaceutical Sciences, 1996
    Co-Authors: A J Hoogstraate, A Pijpers, Leo Van Leengoed, J H M Verheijden, H E Junginger, J C Verhoef, H E Bodde
    Abstract:

    Buccal delivery of fluorescein isothiocyanate labeled dextran 4400 (FD4) was investigated in-vivo in pigs. The delivery device consisted of an application chamber with a solution of FD4 and was adhered to the Buccal mucosa for 4 h using an adhesive patch. A randomized crossover study including intravenous administration and Buccal delivery without and with 10 mM sodium glycodeoxycholate (GDC) as absorption enhancer was performed in five pigs. After Buccal administration, steady state plasma levels were rapidly reached. Coadministration of 10 mM GDC increased the absolute bioavailability of FD4 from 1.8 ± 0.5% to 12.7 ± 2.0%. Since FD4 is a macromolecular and hydrophilic compound such as peptide and protein drugs, Buccal delivery would provide an adequate alternative to the parenteral administration of these drugs.

  • diffusion rates and transport pathways of fluorescein isothiocyanate fitc labeled model compounds through Buccal epithelium
    Pharmaceutical Research, 1994
    Co-Authors: Janet A Hoogstraate, Coos J Verhoef, H E Junginger, Christopher Cullander, Fred J Nagelkerke, S Senel, H E Bodde
    Abstract:

    The aim of this study was to characterize transport of FITC-labeled dextrans of different molecular weights as model compounds for peptides and proteins through Buccal mucosa. The penetration of these dextrans through porcine Buccal mucosa (a nonkeratinized epithelium, comparable to human Buccal mucosa) was investigated by measuring transBuccal fluxes and by analyzing the distribution of the fluorescent probe in the epithelium, using confocal laser scanning microscopy for visualizing permeation pathways. The results revealed that passage of porcine Buccal epithelium by hydrophilic compounds such as the FITC-dextrans is restricted to permeants with a molecular weight lower than 20 kDa. The permeabilities of Buccal mucosa for the 4- and 10-kDa FITC-dextran (of the order of 10−8 cm/sec) were not significantly different from each other or from the much smaller compound FITC. The confocal images of the distribution pattern of FITC-dextrans showed that the paracellular route is the major pathway through Buccal epithelium.

Coos J Verhoef - One of the best experts on this subject based on the ideXlab platform.

  • recent advances in Buccal drug delivery and absorption in vitro and in vivo studies
    Journal of Controlled Release, 1999
    Co-Authors: H E Junginger, Janet A Hoogstraate, Coos J Verhoef
    Abstract:

    Abstract In the first part of this study, the aim was to characterize transport of fluorescein isothiocyanate (FITC)-labelled dextrans of different molecular weights as model compounds for peptides and proteins through Buccal mucosa. The penetration of these dextrans through porcine Buccal mucosa (a nonkeratinized epithelium, comparable to human Buccal mucosa) was investigated by measuring transBuccal fluxes and by analyzing the distribution of the fluorescent probe in the epithelium, using confocal laser scanning microscopy for visualizing permeation pathways. The results revealed that passage of hydrophilic compounds such as the FITC–dextrans through porcine Buccal epithelium is restricted to permeants with a molecular weight lower than 20 kDa. The permeabilities of Buccal mucosa for the 4 and 10 kDa FITC–dextran (of the order of 10 −8 cm/s) were not significantly different from each other or from the much smaller compound FITC. The confocal images of the distribution pattern of FITC–dextrans showed that the paracellular route is the major pathway through Buccal epithelium. In the in vivo part of this study, Buccal delivery of FITC-labelled dextran 4400 (FD4) and the peptide drug buserelin was investigated in vivo, in pigs. The delivery device consisted of an application chamber with a solution of FD4 or buserelin, and was attached to the Buccal mucosa for 4 h using an adhesive patch. A randomized cross-over study including intravenous administration and Buccal delivery without and with 10 mM sodium glycodeoxycholate (GDC) as an absorption enhancer was performed in pigs. After Buccal administration, steady-state plasma levels were rapidly achieved. Co-administration of 10 mM GDC increased the absolute bioavailability from 1.8±0.5 to 12.7±2.0% for FD4. From the present studies, it is concluded that Buccal administration is a suitable route for the delivery for macromolecules and hydrophilic compounds such as peptide drugs.

  • in vivo Buccal delivery of the peptide drug buserelin with glycodeoxycholate as an absorption enhancer in pigs
    Pharmaceutical Research, 1996
    Co-Authors: Janet A Hoogstraate, Coos J Verhoef, A Pijpers, Leo Van Leengoed, J H M Verheijden, H E Junginger, H E Bodde
    Abstract:

    Purpose. To study the potential of Buccal delivery of the peptide drug in pigs. Methods. Intravenous administration and Buccal delivery without and with 10 mM sodium glycodeoxycholate (GDC) as absorption enhancer were investigated as a randomised cross-over study in six pigs. The Buccal delivery device consisted of an application chamber with a solution of buserelin and was attached to the Buccal mucosa for 4 hours using an adhesive patch. Results. Buccal administration of buserelin resulted in rapidly reached steady state plasma levels. The absolute bioavailability of the peptide after Buccal delivery for 4 hours could be increased from 1.0 ± 0.3 to 5.3 ± 1.1% (mean ± S.D.) by co-administration of 10 mM GDC (0.45% w/v)). Conclusions. The results of this study demonstrate that Buccal administration with the use of absorption enhancers is a useful approach for the delivery of peptide drugs such as buserelin.

  • diffusion rates and transport pathways of fluorescein isothiocyanate fitc labeled model compounds through Buccal epithelium
    Pharmaceutical Research, 1994
    Co-Authors: Janet A Hoogstraate, Coos J Verhoef, H E Junginger, Christopher Cullander, Fred J Nagelkerke, S Senel, H E Bodde
    Abstract:

    The aim of this study was to characterize transport of FITC-labeled dextrans of different molecular weights as model compounds for peptides and proteins through Buccal mucosa. The penetration of these dextrans through porcine Buccal mucosa (a nonkeratinized epithelium, comparable to human Buccal mucosa) was investigated by measuring transBuccal fluxes and by analyzing the distribution of the fluorescent probe in the epithelium, using confocal laser scanning microscopy for visualizing permeation pathways. The results revealed that passage of porcine Buccal epithelium by hydrophilic compounds such as the FITC-dextrans is restricted to permeants with a molecular weight lower than 20 kDa. The permeabilities of Buccal mucosa for the 4- and 10-kDa FITC-dextran (of the order of 10−8 cm/sec) were not significantly different from each other or from the much smaller compound FITC. The confocal images of the distribution pattern of FITC-dextrans showed that the paracellular route is the major pathway through Buccal epithelium.

P Van Der Bijl - One of the best experts on this subject based on the ideXlab platform.

  • comparative permeability of various chemical markers through human vaginal and Buccal mucosa as well as porcine Buccal and mouth floor mucosa
    Archives of Oral Biology, 2004
    Co-Authors: P Van Der Bijl
    Abstract:

    Abstract A number of drugs undergo extensive first-pass metabolism after oral administration, necessitating large doses for effective therapeutic responses in the body. Buccal administration of drugs is becoming more popular because the drugs diffuse into the systemic circulation directly, circumventing the first-pass metabolism. Lower concentrations thus need to be administered and side effects may be minimized. In this study, one of the classic models for human Buccal permeability, i.e. the porcine Buccal mucosal model, is compared with the more recent human vaginal model and both these are in turn further compared to porcine mouth floor mucosa. To determine the permeability of the different markers (arecoline, 17β-estradiol, water and vasopressin), a continuous flow-through perfusion system was used (20 °C, 24 h). Mean steady state flux values were compared statistically using a t -test at a significance level of 5%. Porcine Buccal mucosa showed a consistently lower permeability towards all the markers than the other mucosae tested. Porcine mouth floor mucosa was found to be more permeable than porcine Buccal mucosa. From these studies we concluded that human vaginal and porcine mouth floor mucosae were superior models for human Buccal mucosa than porcine Buccal mucosa, using in vitro permeability studies with various chemical markers.

  • permeation of sumatriptan through human vaginal and Buccal mucosa
    Headache, 2000
    Co-Authors: P Van Der Bijl, L Penkler
    Abstract:

    Continued interest in the various routes by which sumatriptan may be administered prompted us to investigate its passage through Buccal mucosa. Because human Buccal mucosa is scarce, we proposed using the relatively abundant vaginal mucosa, which has been shown to have comparable diffusion rates for a number of widely varying molecules, as a model of Buccal mucosa. In addition, by comparing these two tissues with respect to their permeability to sumatriptan, the human vaginal/Buccal mucosa model could be further evaluated. Clinically healthy human vaginal and Buccal mucosa specimens were used in the permeability studies. Permeability to sumatriptan was determined using a continuous flow-through diffusion system in the presence and absence of permeation enhancers. No statistically significant differences in permeability could be demonstrated for both mucosae toward sumatriptan. Flux values obtained in the absence and presence of glycodeoxycholate and lauric acid (1:1 molar ratio) to sumatriptan of Buccal and vaginal mucosa, respectively, were not significantly different. The results obtained further support the hypothesis of the vaginal/Buccal mucosal in vitro permeability model and suggest that this model may be used in conjunction with various absorption enhancers. Further studies on the Buccal route of absorption of sumatriptan are thus warranted.

  • diffusion rates of vasopressin through human vaginal and Buccal mucosa
    European Journal of Oral Sciences, 1998
    Co-Authors: P Van Der Bijl, I O Thompson, Ilse Stander
    Abstract:

    : The permeability to several chemical compounds and the histology of vaginal and Buccal mucosa are very similar. Because vaginal mucosa is more abundant, it may be used as a model for the latter. To further develop the vaginal/Buccal mucosa model, the objective of the present study was to evaluate the passage of a small polypeptide, vasopressin, across fresh and frozen specimens of these two mucosae. Specimens of fresh Buccal and vaginal mucosa were taken from excised tissue obtained following vaginal hysterectomies and various oral surgical procedures. Pieces of Buccal and vaginal tissue specimens obtained were used fresh or were snap-frozen and stored at -85 degrees C for periods of up to 10 months. Biopsies from fresh and thawed specimens were mounted in flow-through diffusion cells and their permeability to tritiated vasopressin was determined using a continuous flow-through perfusion system. Specimens were examined histologically before and after freezing as well as before and after permeability experiments and similarities between vaginal and Buccal tissues verified. No statistically significant differences between flux values for fresh and frozen vaginal and Buccal mucosa, respectively, were found. These results demonstrate that the permeation of vasopressin across fresh and frozen human vaginal and Buccal mucosa is for practical purposes similar. These results further support the human vaginal/Buccal mucosa model for in vitro permeability studies on therapeutically active compounds.

Ginette Horchollebossavit - One of the best experts on this subject based on the ideXlab platform.

  • is there a common drive for Buccal movements associated with Buccal and lung breath in lithobates catesbeianus
    Respiratory Physiology & Neurobiology, 2020
    Co-Authors: Brigitte Quenet, Ginette Horchollebossavit, Stephanie Fournier, Tara Adele Janes, Richard Kinkead
    Abstract:

    Abstract In amphibians, there is some evidence that (1) anatomically separate brainstem respiratory oscillators are involved in rhythm generation, one for the Buccal rhythm and another for the lung rhythm and (2) they become functionally coupled during metamorphosis. The present analysis, performed on neurograms recorded using brainstem preparations from Lithobates catesbeianus, aims to investigate the temporal organisation of lung and Buccal burst types. Continuous Wavelet Transfom applied to the separated Buccal and lung signals of a neurogram revealed that both Buccal and lung frequency profiles exhibited the same low frequency peak around 1 Hz. This suggests that a common ‘clock’ organises both rhythms within an animal. A cross-correlation analysis applied to the Buccal and lung burst signals revealed their similar intrinsic oscillation features, occurring at approximately 25 Hz. These observations suggest that a coupling between the lung and Buccal oscillators emerges at metamorphosis. This coupling may be related to inter-connectivity between the two oscillators, and to a putative common drive.

  • new insights in gill Buccal rhythm spiking activity and co2 sensitivity in pre and postmetamorphic tadpoles pelophylax ridibundus
    Respiratory Physiology & Neurobiology, 2014
    Co-Authors: Brigitte Quenet, Christian Straus, Marienoelle Fiamma, Isabelle Rivals, Thomas Similowski, Ginette Horchollebossavit
    Abstract:

    Abstract Central CO2 chemosensitivity is crucial for all air-breathing vertebrates and raises the question of its role in ventilatory rhythmogenesis. In this study, neurograms of ventilatory motor outputs recorded in facial nerve of premetamorphic and postmetamorphic tadpole isolated brainstems, under normo- and hypercapnia, are investigated using Continuous Wavelet Transform spectral analysis for Buccal activity and computation of number and amplitude of spikes during Buccal and lung activities. Buccal bursts exhibit fast oscillations (20–30 Hz) that are prominent in premetamorphic tadpoles: they result from the presence in periodic time windows of high amplitude spikes. Hypercapnia systematically decreases the frequency of Buccal rhythm in both pre- and postmetamorphic tadpoles, by a lengthening of the interburst duration. In postmetamorphic tadpoles, hypercapnia reduces Buccal burst amplitude and unmasks small fast oscillations. Our results suggest a common effect of the hypercapnia on the Buccal part of the Central Pattern Generator in all tadpoles and a possible effect at the level of the motoneuron recruitment in postmetamorphic tadpoles.