Yann Pellequer

University of Franche-Comté, Becoinson, Franche-Comté, France

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Publications (33)115.68 Total impact

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    ABSTRACT: Nanoparticles (NPs) are currently used as drug delivery systems for numerous therapeutic macromolecules, e.g. proteins or DNA. Based on the preparation by double emulsion solvent evaporation a sponge-like structure was postulated entrapping hydrophilic drugs inside an internal aqueous phase. However, a direct proof of this hypothesized structure is still missing today. NPs were prepared from different polymers using a double-emulsion method and characterized for their physicochemical properties. Combining ion milling with field emission scanning electron microscopy allowed to cross section single NP and to visualize their internal morphology. The imaging procedure permitted cross-sectioning of NPs and visualization of the internal structure as well as localizing drugs associated with NPs. It was observed that none of the model actives was encapsulated inside the polymeric matrix when particle diameters were below around 470nm but predominantly adsorbed to the particle surface. Even at larger diameters only a minority of particles of a diameter below 1μm contained an internal phase. The properties of such drug loaded NPs, i.e. drug release or the observations in cellular uptake or even drug targeting needs to be interpreted carefully since in most cases NP surface properties are potentially dominated by the 'encapsulated' drug characteristics. Copyright © 2014. Published by Elsevier B.V.
    European Journal of Pharmaceutics and Biopharmaceutics. 11/2014;
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    ABSTRACT: Topical treatment of skin diseases is an attractive strategy as it receives high acceptance from patients, resulting in higher compliance and therapeutic outcomes. Recently, the use of variable nanocarriers for dermal application has been widely explored, as they offer several advantages compared with conventional topical preparations, including higher skin penetration, controlled and targeted drug delivery and the achievement of higher therapeutic effects. This article will focus on skin inflammation or dermatitis as it is one of the most common skin problems, describing the different types and causes of dermatitis, as well as the typical treatment regimens. The potential use of nanocarriers for targeting skin inflammation and the achievement of higher therapeutic effects using nanotechnology will be explored.
    Nanomedicine (London, England). 08/2014; 9(11):1727-1743.
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    ABSTRACT: A major limitation in the drug treatment of inflammatory bowel disease is the inability to deliver the drug selectively towards the inflamed tissues. Nanotechnology-based drug delivery systems have led to an amelioration of the therapeutic selectivity but still the majority of the entrapped drug is eliminated without exercising a therapeutic effect. Here, lectin-decorated drug loaded nanoparticles (NP) are suggested for active targeting and selective adhesion to the inflamed tissue in experimental colitis. Peanut (PNA) and wheat germ (WGA) lectins were covalently bound to the surface of NP and were tested for their stability and degree of bioadhesion in cell culture. In-vivo, the selectivity of bioadhesion and distribution of NP throughout the intestinal tract as well as the therapeutic benefit for glucocorticoid loaded lectin-NP was studied in murine colitis models. Quantitative adhesion analyses showed that lectin-conjugated NP exhibited a much higher binding and selectivity to inflamed tissue compared to plain NP (PNA conjugates: 52.2±5.6%; WGA conjugates: 22.0±0.8%; plain NP: 18.6±9.8%). Lectin-associated NP revealed a further increase in the selectivity of bioadhesion towards inflamed tissues which partially translates into increased therapeutic efficiency. In terms of therapeutic efficiency, all glucocorticoid containing formulations revealed an enhanced therapeutic effect with lectin conjugates especially PNA-NP (myeloperoxidase: 55±37U/g; TNF-alpha: 3880±380U/g) compared to plain NP (myeloperoxidase: 145±98U/g; TNF-alpha: 6971±1157U/g). Targeted NP by using lectins, especially with PNA, as stable targeting moiety in the gastrointestinal tract appears to be a very promising tool in future treatment of inflammatory bowel disease.
    Journal of controlled release : official journal of the Controlled Release Society. 06/2014;
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    ABSTRACT: Standard monoculture models utilizing Caco-2 monolayers were extensively used to mimic the permeability of the human intestinal barrier. However, they exhibit numerous limitations such as the lack of mucus layer, an overestimation of the P-gp-mediated efflux and a low paracellular permeability. Here, we suggest a new procedure to set up an in vitro model of intestinal barrier to adjust gradually the properties of the absorption barrier. Mucin-secreting HT29-MTX cells were added to Caco-2 absorptive cells in a Transwell(®) at different time intervals.. Effects of seeding day of HT29-MTX on the paracellular permeability of lucifer yellow (LY) and on the P-gp-mediated efflux of rhodamine 123 was investigated. Apparent permeability of the rhodamine 123 in the secretory direction was highly dependent on the seeding day of goblet cells. Transepithelial electrical resistance values and LY transport across the co-cultures in the apical-to-basolateral direction were intermediary between single Caco-2 and HT29-MTX models. Early seeding days of HT29-MTX allowed increasing the fraction of goblet cells in the co-culture. Co-culture permeability was unchanged between 21 and 30 days after Caco-2 seeding, corresponding to the period of use for Caco-2-based cell models. Thus, the HT29-MTX seeding day was a key factor to set up an in vitro intestinal model with tailor-made barrier properties in terms of P-gp expression and paracellular permeability.
    European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 04/2014; · 3.15 Impact Factor
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    ABSTRACT: The efflux transporter P-glycoprotein, expressed at high levels at the blood-brain barrier, exerts a profound effect on the disposition of various therapeutic compounds in the brain. A rapid and efficient modulation of this efflux transporter could enhance the distribution of its substrates and thereby improve central nervous system pharmacotherapies. This study explored the impact of the intravenous co-administration of two P-glycoprotein modulators, tariquidar and elacridar, on the pharmacokinetics and brain distribution of loperamide, a P-glycoprotein substrate probe, in rats. After one hour post-dosing, tariquidar and elacridar, both at a dose of 1.0 mg/kg, increased loperamide levels in the brain by 2.3- and 3.5-fold, respectively. However, the concurrent administration of both P-glycoprotein modulators, each at a dose of 0.5 mg/kg, increased loperamide levels in the brain by 5.8-fold and resulted in the most pronounced opioid-induced clinical signs. This phenomenon may be the result of a combined non-competitive modulation by tariquidar and elacridar. Besides, the simultaneous administration of elacridar and tariquidar did not significantly modify the pharmacokinetic parameters of loperamide. This observation potentially allows the concurrent use of low but therapeutic doses of P-gp modulators to achieve full inhibitory effects.
    Drug metabolism and disposition: the biological fate of chemicals 01/2014; · 3.74 Impact Factor
  • European Journal of Pharmaceutics and Biopharmaceutics. 01/2014;
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    ABSTRACT: Inflammatory bowel disease is a chronic relapsing inflammation of the gut with the two main forms ulcerative colitis and Crohn's disease. Nanoparticulate drug carrier systems have proven to enhance the therapeutic efficiency and to diminish adverse effects of the anti-inflammatory treatment due to their size dependent accumulation in the inflamed regions of the gut. The influence of surface properties on the accumulation selectivity and intensity of such nanoparticles is mainly unclear. Accordingly sized particles (~200 nm) were prepared by the emulsification solvent evaporation technique using different surfactants (polysorbate 20, sodium dodecylsulphate, sodium cholate, cetyltrimethylammonium bromide, polyvinyl alcohol). In a murine colitis model the particles prepared with polysorbate 20 as surfactant led to an 34.8-fold higher particle content in the inflamed areas of the colon compared to the healthy gut and to a 4.5-fold increase of the particle content in the inflamed segments compared to particles prepared with sodium dodecylsulphate. This effect translates also into a significantly higher mitigating effect when entrapping betamethasone into such nanoparticles. This study shows the importance of surface properties for the passive targeting approach in experimental colitis. The influence seems to be as important as the influence by the particle size.
    Journal of Controlled Release 08/2013; · 7.63 Impact Factor
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    ABSTRACT: For the treatment of glioblastoma multiforme, an "anticancer drug cocktail" delivered by biodegradable poly-lactide-co-glycolide (PLGA)-microspheres is proposed. Celecoxib, etoposide, and elacridar were encapsulated by an oil/water emulsification solvent evaporation method. Drug-loaded microspheres were analyzed for their physicochemical properties and evaluated in a rat glioblastoma model. Microspheres had a mean diameter 10-20 µm, and encapsulation rates varied upon lipophilicity of the drug (celecoxib: 97.4 ± 0.4%; elacridar: 98.1 ± 0.3%; and etoposide: 38.7 ± 8.3%). Drug release of celecoxib and elacridar resulted in a burst (t50: 3.1 h and 1.0 h, respectively) while etoposide release was slower (t50: 45.3 h). The comparison of celecoxib (p = 0.021) and etoposide microspheres (p = 0.002) as well as their combination (p = 0.011) led to a significant increase in the probability of survival compared to blank microspheres. Local delivery of celecoxib and etoposide microspheres was found to be suitable for the treatment of glioblastoma in rats although simultaneous drug administration did not improve the therapeutic outcome.
    Journal of Microencapsulation 03/2013; · 1.57 Impact Factor
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    ABSTRACT: Nanoparticles (NPs) have shown a certain potential to overcome the drawbacks of oral peptide delivery in the gastrointestinal tract such as low peptide stability and permeability. The preparation of insulin loaded NPs was carried out with Eudragit® RL or RS dissolved in different non-toxic polyethylene glycol (PEG) derivatives. The use of these non-toxic solvents allowed the design of an one step NP preparation method where insulin retained its full biological activity as it was proven in vitro and in vivo. The insulin trapping NPs were in a size range of around 150 to 250nm and exhibited a pH-dependent release. The type of solvent did not distinctly influence the particle properties or insulin stability but modified significantly the performance in vivo in rats, NPs prepared with glycofurol led to a bioavailability of F=1.4±1.0% after oral administration while NPs prepared with PEG 300 were hardly efficient (F=0.3± 0.5%). In all cases t(max) was shifted to 2h compared to 1h after subcutaneous insulin solution. In general, we believe that the method presented here is a promising way to encapsulate sensitive drugs, especially for the production of peptide loaded NPs.
    International Journal of Pharmaceutics 01/2013; · 3.99 Impact Factor
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    ABSTRACT: Oxycellulose belongs to the wide range of pharmaceutically and medically used cellulose derivatives unique in its properties of biodegradability, non-toxicity, antioxidative activity, haemostasis supporting, tissue healing improvement, etc. Glycyrrhizin (Gly) represents the most prominent licorice triterpenoid glycoside, which is responsible for its pharmacological activity, and is closely linked to increasing levels of gastroprotective prostaglandins. In order to study the anti-ulcer activity of oxycellulose sodium and Gly, pellets containing only oxycellulose, or in combination with glycyrrhizin, were prepared using an extrusion/spheronization method. The physical properties and in vitro release rate of the prepared pellets were tested. Based on the obtained results, one sample prepared from oxycellulose only, and one containing glycyrrhizin were chosen for in vivo testing. The healing effect of the prepared pellet formulations was evaluated in the acetic acid induced gastric ulcers in rats. The improvement in gastric ulcer healing was documented for myeloperoxidase activity, alkaline phosphatase activity and gastric wall mucin levels using the Alcian blue binding capacity. The tested pellets significantly reduced myeloperoxidase and alkaline phosphatase activity, and increased gastric wall mucus levels compared to the non-treated group. The in vivo tests showed that oral administration of the prepared pellets accelerated the healing of gastric ulcers in rats.
    Cellulose 01/2013; 20(3). · 3.48 Impact Factor
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    ABSTRACT: Polymeric nanoparticles (NPs) are interesting drug carriers for dermal application and drug targeting to certain skin structures. NP interactions with diseased skin and the associated benefits and risks have been hardly explored. Today, we study the behavior of polymeric NPs for selective drug delivery to inflamed skin. Neutral, cationic, and anionic NPs of nominal diameters around 100 nm were administered to an experimental dithranol-induced dermatitis inflammation model in mice ears. The results showed that the surface charge had an important influence on the penetration and accumulation tendency in the inflamed skin compared with the neutral and cationic (2.8 ± 0.3%, 2.1 ± 0.2%, and 1.9 ± 0.3% for anionic, neutral, and cationic particles, respectively). Confocal laser scanning microscopy showed that all particles were accumulated in the inflamed pilosebaceous units. Betamethasone-loaded NPs showed that both charged particles were therapeutically more efficient than the neutral ones. Treatment with anionic and cationic particles led to the reduction of the inflammatory enzyme alkaline phosphatase activity by 50.7 ± 2% and 57.7 ± 5%, respectively, in comparison with the inflamed control. Noncharged particles had a lower therapeutic impact where the activity was only reduced by a factor of 75%. Histological sections examination had also confirmed these results. Therefore, it was concluded that the presence of charge could enhance skin-NPs adhesion and interaction leading to higher therapeutic effect on inflamed skin. © 2012 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 101:4231-4239, 2012.
    Journal of Pharmaceutical Sciences 08/2012; 101(11):4231-9. · 3.13 Impact Factor
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    ABSTRACT: Inflammatory reactions of the skin are a major therapeutic field; however, drug delivery is nowadays only related to the use of classical formulations like ointments and creams. Here, we report the behaviour of polymeric submicron particles (NP) for selective drug delivery to the inflamed skin. NPs of nominal diameters from 50 to 1000nm were administered to an experimental dithranol-induced dermatitis inflammation model in mice ears. The results revealed that smaller particles had an around 3-fold stronger and deeper penetration tendency with a preferential accumulation in inflamed skin hair follicles and sebaceous glands (2.8±0.6% and 2.3±0.4% for NP100 and NP50 compared to 0.84±0.04% and 0.92±0.02% for the same sizes on healthy skin). Betamethasone loaded NP confirmed the size dependency by being therapeutically more efficient from histological examination and measurement of different inflammatory markers in the skin (myeloperoxidase activity of untreated control, 1.2±0.4; NP1000, 1.0±0.4; NP100, 0.5±0.2, all U/mg). This approach holds a high potential for a selective therapy to the inflamed skin by increasing the local intradermal availability with simultaneous reduction in systemic adverse effects.
    European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 06/2012; 82(1):151-7. · 3.15 Impact Factor
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    ABSTRACT: As a result of its broad substrate specificity and critical localization in excretory and barrier function tissues, P-glycoprotein (P-gp) plays major roles in the pharmacokinetics, safety and efficacy profiles of numerous drugs. P-gp is often responsible for the failure of many chemical treatments against cancer, immunosuppressive, infectious and neurodegenerative diseases. Among the therapeutic approaches to circumvent P-gp function, advances in the design of new chemical P-gp modulators to interact specifically with P-gp have yielded few clinical successful reports. Members of a class of components that were initially developed as surface active agents showed promising results with regard to the modulation of P-gp. These components include surfactants and amphiphilic co-polymers. Alternatively, colloidal systems were developed to facilitate drug uptake in resistant cells. This approach is based on the encapsulation of drugs, which masks them from the biological environment and prevents their transport by P-gp using the surfactants released from the nanocarrier. Likewise, a novel and synergistic strategy is currently being explored and involves nanocarrier-mediated transport and controlled release of both P-gp substrates and P-gp modulators. In this review, we discuss recent results obtained by direct modulation with chemosensitizers and the available nanotechnology to modulate P-gp function. In this manuscript, we also discuss unexplored pathways for future therapies.
    Journal of Controlled Release 04/2012; 161(1):50-61. · 7.63 Impact Factor
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    ABSTRACT: In inflammatory bowel disease (IBD) the disruption of the intestinal barrier function and the strong presence of immune-related cells like macrophages in inflamed tissue allow the selective accumulation of particulate carrier systems at the site of action. We developed clodronate loaded nanoparticles (ClNP) based on a cationic polymethacrylate (Eudragit RL) using a modified solvent displacement method. Particle diameter of ClNP was around 120nm and dissolution experiments showed that ionic interactions with either the dissolution medium or mucin have to take place to enable complete drug release. In murine experimental colitis in-vivo, myeloperoxidase activity decreased significantly in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-colitis and oxazolone (OXA)-colitis models after treatment with ClNP while free clodronate did not show a mitigating effect. Similarly, alkaline phosphatase could be lowered significantly from 12.5±1.9 to 6.8±2.2ng/mg tissue in TNBS-colitis and from 16.6±6.2 to 11.8±2.7ng/mg tissue in OXA-colitis. In cultured RAW 264.7 cells, only ClNP but not clodronate alone led to a decrease in tumor necrosis factor-alpha and interleukin-6 secretion of the activated macrophages. The therapeutic benefit of ClNP was confirmed in-vivo although it is limited compared to data with other drugs. Cell culture experiments indicated that intracellular delivery of clodronate was necessary to obtain an anti-inflammatory effect.
    Journal of Controlled Release 03/2012; 160(3):659-65. · 7.63 Impact Factor
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    ABSTRACT: Topical delivery of 5-aminosalicylic acid (5-ASA) to the colonic mucosa is important in order to achieve effective drug concentration in the site of inflammation and to minimize its systemic availability. 5-ASA loaded pellets were prepared by an extrusion/spheronization method. Mucoadhesive biopolymer chitosan was incorporated into the pellets, and drug delivery to the colon was controlled by the pH-sensitive polymer Eudragit® FS. Dissolution profiles of coated pellets revealed no drug release at pH 1.2 within 2h and release as intended in the simulated distal ileum and colon. In vivo, chitosan-core drug loaded pellets (AMCh) showed 2.5-fold higher drug metabolite concentration than after chitosan free pellets (AM) administration in the inflamed colonic tissue. Additionally, AMCh demonstrated decreased in AUC in colitis group (1507 ± 400 ng h/ml) compared with AM (1907 ± 122 ng h/ml). In terms of therapeutic efficiency, administration of pellets markedly decreased the colon/body weight ratio (colitis: 0.0355 ± 0.0028; AM 0.0092 ± 0.0033; AMCh 0.0086 ± 0.0022) and myeloperoxidase activity (colitis: 3212 ± 294 U/g tissue; AM 796 ± 211 U/g; AMCh 552 ± 319 U/g). Bioadhesive chitosan pellets showed additional beneficial properties for colonic 5-ASA delivery in the treatment of inflammatory bowel disease by increasing the drug concentration locally.
    European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 02/2012; 81(2):379-85. · 3.15 Impact Factor
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    ABSTRACT: Preparation of coated pellets intended for rutin colon delivery, their evaluation in vitro and in vivo in experimental colitis in rats was the purpose of this study. Pellets were obtained using extrusion/spheronization and coated with three types of coatings (caffeic acid/hypromellose/alginic acid; sodium alginate/hypromellose/zinc acetate; sodium alginate/chitosan). Dissolution using buffers of pH values, β-glucosidase and times corresponding to gastrointestinal tract (GIT) was provided. Pellets coated with alginate/chitosan showed low rutin dissolution (12-14%) in upper GIT conditions and fast release (87-89%) under colon conditions; that is a good presumption of intended rutin release. After colitis induction and development, the rats were treated with pellets and rutin solution administered orally, solution also rectally. Colon/body weight ratio, myeloperoxidase activity and histological evaluation were performed. Rutin was able to promote colonic healing at the dose of 10mg/kg: colon/body weight ratio decreased and myeloperoxidase activity was significantly suppressed. Pellets coated with alginate/chitosan applied orally and rutin solution administered rectally showed the best efficacy. The combination of rutin as natural product, mucoadhesive chitosan degraded in the colon and sodium alginate as the main coating substance in the form of pellets create a promising preparation for therapy of this severe illness.
    International Journal of Pharmaceutics 11/2011; 422(1-2):151-9. · 3.99 Impact Factor
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    ABSTRACT: Zinc-pectinate beads are interesting drug carriers for oral delivery. In order to investigate their in vitro and in vivo release behaviour, ionotropic gelation was used to entrap theophylline into calcium- or zinc-pectinate beads. Beads were investigated in vitro for their particle properties, especially the release kinetic in different media, and their in vivo pharmacokinetic parameters were tested in rats. Particle size varied between 1.8 and 2.8mm and encapsulation rates between 27 and 30% for Ca- and Zn-pectinate beads, respectively. While Ca-pectinate beads revealed a relative fast disintegration, drug release profiles from Zn-pectinate beads were very much release medium-dependent. Especially, in the presence of phosphate ions, the release from Zn-pectinate beads was blocked at 20% and 40% of the total drug load when tested in phosphate buffer or simulated colonic medium. In vivo Zn-pectinate beads (t(max): 12.0 ± 0.1h) led to a significant lag time for the theophylline absorption compared to Ca-pectinate (t(max): 6.0 ± 2.8h) or free theophylline (t(max): 2.5 ± 2.1h). This delayed release was attributed to the formation of a zinc phosphate coating in vitro and in vivo inducing the retention of theophylline release. Zn-pectinate beads exhibit interesting properties due to its potential as pulsatile delivery system induced by the in situ formation of Zn phosphate, while Ca-pectinate was found to be of limited suitability for controlled release of theophylline.
    International Journal of Pharmaceutics 05/2011; 414(1-2):28-34. · 3.99 Impact Factor
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    ABSTRACT: Lipid nanocapsules (LNC) have been suggested for a variety of pharmaceutical applications. Among them approaches for drug delivery to the skin appear particularly interesting. The current standard composition has been modified to better understand their properties by selecting a variety of different surfactants. LNC have been prepared using different non-ionic surfactants (Solutol(®) HS15: Polyoxyl 15 Hydroxystearate; Cremophor(®) EL: Polyoxyl 35 Castor Oil; Simulsol(®) 4000: Polyoxyl 40 Hydrogenated Castor Oil; Vitamin E TPGS(®): alpha-tocopheryl poly(ethylene glycol) succinate; Polysorbate 20 and 80) and analysed for their size, stability, drug release and toxicity on keratinocytes in cell culture. The feasibility of LNC using different surfactant was surprisingly easy and led to a variety of stable formulations that were selected for further investigations. Surfactants led to a variability of the release kinetics (t50% release varied from Polysorbate 20: 2.5h to Simulsol(®) 4000: 5.0h), however different formulations from the same surfactant did not differ significantly. In vitro toxicity of LNC was surfactant type dependent and a correlation between LNC and the pure respective surfactant was found. This toxicity was found to be mainly independent from the surface active properties. The surfactant type in LNC is easily interchangeable from formulation point of view. LNC appear to be appropriate as carrier for cutaneous delivery however toxicity can vary distinctly depending on the surfactant used for the preparation.
    International Journal of Pharmaceutics 04/2011; 411(1-2):136-41. · 3.99 Impact Factor
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    ABSTRACT: The colonic drug delivery in inflammatory bowel disease (IBD) by microcarriers has been suggested over the past decade; however, pharmacokinetic and biopharmaceutical details are hardly known. A model colitis was induced to male Wistar rats by trinitrobenzenesulfonic acid. Carboxyfluorescein (CF) was entrapped into microspheres (MS) prepared with the pH-sensitive polymer Eudragit® S100, in order to simulate drug delivery to the colon. Pharmacokinetic behaviour of CF-MS was compared to oral or rectal administration of CF as solution in healthy or colitis group. Colitis lowered the oral bioavailability of CF solution, compared to healthy controls (healthy: 8.4±1.5; colitis: 3.0±0.9; all μg/mlh), and similar results were obtained after rectal administration of CF solution (healthy: 5.6±2.1; colitis: 1.8±0.8). Surprisingly, CF-MS showed only minor differences between colitis and healthy controls (healthy: 1.9±0.8; colitis: 2.3±0.4). In contrary, the intra-tissue concentrations of CF of the various formulations in colitis showed lower levels than the comparable healthy group after oral drug administration. Pharmacokinetic outcome was largely disease-dependent, while CF-MS confirmed their ability to local drug delivery.
    European journal of pharmaceutics and biopharmaceutics: official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 10/2010; 76(2):290-5. · 3.15 Impact Factor
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    Saad Hassani, Yann Pellequer, Alf Lamprecht
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    ABSTRACT: Purpose Gastrointestinal deposition of nanoparticles was examined after oral administration to mice suffering from an experimental gastric ulcer model. Local drug delivery could reduce side effects and would be a distinct improvement compared to existing therapeutic approaches, e.g. in the local therapy of Helicobacter pylori. Methods A gastric ulcer was induced to Swiss mice by acetic acid injection. Fluorescent polystyrene particles with a nominal size of 50, 200, and 750 nm were administered orally for 3 or 5 days and particle adhesion in the gastrointestinal tract analyzed. Results In the ulcerated regions, an enhanced particle adhesion was observed compared to healthy controls. A size dependency of the deposition was found which further increased with a prolonged treatment period. For 750 nm particles only fair adhesion was observed (control, 2.0 ± 1.4%; ulcer, 4.5 ± 0.7% of daily administered particle mass), while already 200 nm particles showed higher binding (control, 2.9 ± 1.3%; ulcer, 7.8 ± 1.2%). Highest relative adhesion was found for 50 nm particles (control, 2.8 ± 1.3%; ulcer, 10.0 ± 1.5%). The targeting index of gastric ulcer versus healthy control was nearly constant around 2 after 3 days treatment, but increased distinctly for smaller particles after 5 days. Conclusions The use of sub-micron sized carriers holds promise for the targeted delivery of drugs to the ulcerated mucosal areas in the stomach.
    Pharmaceutical Research 06/2009; 26(5):1285. · 4.74 Impact Factor

Publication Stats

272 Citations
115.68 Total Impact Points


  • 2005–2014
    • University of Franche-Comté
      Becoinson, Franche-Comté, France
  • 2012–2013
    • University of Bonn
      Bonn, North Rhine-Westphalia, Germany
    • Ain Shams University
      Al Qāhirah, Al Qāhirah, Egypt
    • University of Veterinary and Pharmaceutical Sciences Brno
      • Department of Pharmaceutics
      Brno, South Moravian Region, Czech Republic
  • 2007
    • Hacettepe University
      • Department of Pharmaceutical Technology
      Ankara, Ankara, Turkey