@article{BalzusSahleHoenzkeetal.2017, author = {Balzus, Benjamin and Sahle, Fitsum Feleke and H{\"o}nzke, Stefan and Gerecke, Christian and Schumacher, Fabian and Hedtrich, Sarah and Kleuser, Burkhard and Bodmeier, Roland}, title = {Formulation and ex vivo evaluation of polymeric nanoparticles for controlled delivery of corticosteroids to the skin and the corneal epithelium}, series = {European journal of pharmaceutics and biopharmaceutics : EJPB ; official journal of the International Association for Pharmaceutical Technology}, volume = {115}, journal = {European journal of pharmaceutics and biopharmaceutics : EJPB ; official journal of the International Association for Pharmaceutical Technology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0939-6411}, doi = {10.1016/j.ejpb.2017.02.001}, pages = {122 -- 130}, year = {2017}, abstract = {Controlled delivery of corticosteroids using nanoparticles to the skin and corneal epithelium may reduce their side effects and maximize treatment effectiveness. Dexamethasone-loaded ethyl cellulose, Eudragit® RS and ethyl cellulose/Eudragit® RS nanoparticles were prepared by the solvent evaporation method. Dexamethasone release from the polymeric nanoparticles was investigated in vitro using Franz diffusion cells. Drug penetration was also assessed ex vivo using excised human skin. Nanoparticle toxicity was determined by MTT and H2DCFDA assays. Eudragit® RS nanoparticles were smaller and positively charged but had a lower dexamethasone loading capacity (0.3-0.7\%) than ethyl cellulose nanoparticles (1.4-2.2\%). By blending the two polymers (1:1), small (105 nm), positively charged (+37 mV) nanoparticles with sufficient dexamethasone loading (1.3\%) were obtained. Dexamethasone release and penetration significantly decreased with decreasing drug to polymer ratio and increased when Eudragit® RS was blended with ethyl cellulose. Ex vivo, drug release and penetration from the nanoparticles was slower than a conventional cream. The nanoparticles bear no toxicity potentials except ethyl cellulose nanoparticles had ROS generation potential at high concentration. In conclusion, the nanoparticles showed great potential to control the release and penetration of corticosteroids on the skin and mucus membrane and maximize treatment effectiveness.}, language = {en} } @misc{DoegeHoenzkeSchumacheretal.2016, author = {Doege, N. and Hoenzke, S. and Schumacher, Fabian and Balzus, Benjamin and Colombo, Miriam and Hadam, S. and Rancan, F. and Blume-Peytavi, Ulrike and Schindler, A. and Ruehl, E. and Skov, P. and Church, Martin K. and Hedtrich, Sarah and Kleuser, Burkhard and Bodmeier, Roland and Vogt, A.}, title = {Ex vivo microdialysis used for the preclinical assessment of anti-inflammatory therapy}, series = {Experimental dermatology : the official journal of the European Immunodermatology Society}, volume = {25}, journal = {Experimental dermatology : the official journal of the European Immunodermatology Society}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0906-6705}, pages = {E32 -- E32}, year = {2016}, language = {en} } @article{DoegeHoenzkeSchumacheretal.2016, author = {D{\"o}ge, Nadine and H{\"o}nzke, Stefan and Schumacher, Fabian and Balzus, Benjamin and Colombo, Miriam and Hadam, Sabrina and Rancan, Fiorenza and Blume-Peytavi, Ulrike and Sch{\"a}fer-Korting, Monika and Schindler, Anke and R{\"u}hl, Eckart and Skov, Per Stahl and Church, Martin K. and Hedtrich, Sarah and Kleuser, Burkhard and Bodmeier, Roland and Vogt, Annika}, title = {Ethyl cellulose nanocarriers and nanocrystals differentially deliver dexamethasone into intact, tape-stripped or sodium lauryl sulfate-exposed ex vivo human skin - assessment by intradermal microdialysis and extraction from the different skin layers}, series = {Journal of controlled release}, volume = {242}, journal = {Journal of controlled release}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0168-3659}, doi = {10.1016/j.jconrel.2016.07.009}, pages = {25 -- 34}, year = {2016}, abstract = {Understanding penetration not only in intact, but also in lesional skin with impaired skin barrier function is important, in order to explore the surplus value of nanoparticle-based drug delivery for anti-inflammatory dermatotherapy. Herein, short-termex vivo cultures of (i) intact human skin, (ii) skin pretreated with tape-strippings and (iii) skin pre-exposed to sodium lauryl sulfate (SLS) were used to assess the penetration of dexamethasone (Dex). Intradermal microdialysis was utilized for up to 24 h after drug application as commercial cream, nanocrystals or ethyl cellulose nanocarriers applied at the therapeutic concentration of 0.05\%, respectively. In addition, Dex was assessed in culture media and extracts from stratum corneum, epidermis and dermis after 24 h, and the results were compared to those in heat-separated split skin from studies in Franz diffusion cells. Providing fast drug release, nanocrystals significantly accelerated the penetration of Dex. In contrast to the application of cream and ethyl cellulose nanocarriers, Dex was already detectable in eluates after 6 h when applying nanocrystals on intact skin. Disruption of the skin barrier further accelerated and enhanced the penetration. Encapsulation in ethyl cellulose nanocarriers delayed Dex penetration. Interestingly, for all formulations highly increased concentrations in the dialysate were observed in tape-stripped skin, whereas the extent of enhancement was less in SLS-exposed skin. The results were confirmed in tissue extracts and were in line with the predictions made by in vitro release studies and ex vivo Franz diffusion cell experiments. The use of 45 kDa probes further enabled the collection of inflammatory cytokines. However, the estimation of glucocorticoid efficacy by Interleukin (IL)-6 and IL-8 analysis was limited due to the trauma induced by the probe insertion. Ex vivo intradermal microdialysis combined with culture media analysis provides an effective, skin-sparing method for preclinical assessment of novel drug delivery systems at therapeutic doses in models of diseased skin. (C) 2016 Elsevier B.V. All rights reserved.}, language = {en} } @misc{DoegeSchumacherBalzusetal.2017, author = {D{\"o}ge, Nadine and Schumacher, Fabian and Balzus, Benjamin and Colombo, Miriam and Hadam, Sabrina and Rancan, Fiorenza and Blume-Peytavi, Ulrike and Kleuser, Burkhard and Bodmeier, Roland and Vogt, Annika}, title = {Particle- based formulations and controlled skin barrier disruption have a signifi cant impact on the delivery and penetration kinetics of dexamethasone as assessed in an ex vivo microdialysis}, series = {Journal der Deutschen Dermatologischen Gesellschaft}, volume = {15}, journal = {Journal der Deutschen Dermatologischen Gesellschaft}, publisher = {Wiley}, address = {Berlin}, issn = {1610-0379}, pages = {182 -- 182}, year = {2017}, abstract = {Preclinical assessment of penetration not only in intact, but also in barrier-disrupted skin is important to explore the surplus value of novel drug delivery systems, which can be specifically designed for diseased skin. Here, we characterized physical and chemical barrier disruption protocols for short-term ex vivo skin cultures with regard to structural integrity, physiological and biological parameters. Further, we compared the penetration of dexamethasone (Dex) in different nanoparticle-based formulations in stratum corneum, epidermis and dermis extracts of intact vs. barrier-disrupted skin as well as by dermal microdialysis at 6, 12 and 24 hours after topical application. Dex was quantified by liquid-chromatography - tandem-mass spectrometry (LC-MS/MS). Simultaneously, we investigated the Dex efficacy by interleukin (IL) analysis. Tape-stripping (TS) and 4 hours sodium lauryl sulfate 5 \% (SLS) exposure were identified as highly effective barrier disruption methods assessed by reproducible transepidermal water loss (TEWL) changes and IL-6/8 increase which was more pronounced in SLS-treated skin. The barrier state has also a significant impact on the Dex penetration kinetics: for all formulations, TS highly increased dermal Dex concentration despite the fact that nanocrystals quickly and effectively penetrated both, intact and barrier-disrupted skin reaching significantly higher dermal Dex concentration after 6 hours compared to Dex cream. The surplus value of encapsulation in ethyl cellulose nanocarriers could mostly be observed when applied on intact skin, in general showing a delayed Dex penetration. Estimation of cytokines was limited due to the trauma caused by probe insertion. In summary, ex vivo human skin is a highly interesting short-term preclinical model for the analysis of penetration and efficacy of novel drug delivery systems.}, language = {en} } @article{SahleBalzusGereckeetal.2016, author = {Sahle, Fitsum Feleke and Balzus, Benjamin and Gerecke, Christian and Kleuser, Burkhard and Bodmeier, Roland}, title = {Formulation and in vitro evaluation of polymeric enteric nanoparticles as dermal carriers with pH-dependent targeting potential}, series = {European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences, EUFEPS}, volume = {92}, journal = {European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences, EUFEPS}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0928-0987}, doi = {10.1016/j.ejps.2016.07.004}, pages = {98 -- 109}, year = {2016}, abstract = {pH-sensitive nanoparticles which release in a controlled fashion on the skin or dissolve in the hair follicle could significantly improve treatment effectiveness and make transfollicular drug delivery a success. Dexamethasone-loaded Eudragit L 100 nanoparticles were prepared by nanoprecipitation from an organic drug-polymer solution. Their toxicity potential was assessed using isolated human fibroblasts. pH-dependent swelling and erosion kinetics of the nanoparticles were investigated by dynamic light scattering and viscosity measurements and its effect on drug release was assessed in vitro with Franz diffusion cells. Stable, 100-550 nm-sized dexamethasone-loaded Eudragit L 100 nanoparticles with drug loading capacity and entrapment efficiency as high as 83\% and 85\%, respectively, were obtained by using polyvinyl alcohol as a stabilizer and ethanol as organic solvent The nanoparticles showed little or no toxicity on isolated normal human fibroblasts. Dexamethasone existed in the nanoparticles as solid solution or in amorphous form. The nanoparticles underwent extensive swelling and slow drug release in media with a low buffer capacity (as low as 10 mM) and a higher pH or at a pH close to the dissolution pH of the polymer (pH 6) and a higher buffer capacity. In 40 mM buffer and above pH 6.8, the nanoparticles eroded fast or dissolved completely and thus released the drug rapidly. pH-sensitive nanoparticles which potentially release in a controlled manner on the stratum corneum but dissolve in the hair follicle could be prepared. (C) 2016 Elsevier B.V. All rights reserved.}, language = {en} }