The Experts below are selected from a list of 81 Experts worldwide ranked by ideXlab platform
Sven Gohla - One of the best experts on this subject based on the ideXlab platform.
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vitamin a loaded solid lipid nanoparticles for topical use drug release properties
Journal of Controlled Release, 2000Co-Authors: Volkhard Jenning, Monika Schaferkorting, Sven GohlaAbstract:Burst release as well as sustained release has been reported for SLN suspensions. For dermal Application, both features are of interest. Burst release can be useful to improve the penetration of a drug. Sustained release becomes important with active ingredients that are irritating at high concentrations or to supply the skin over a prolonged period of time with a drug. Glyceryl behenate SLN were loaded with vitamin A and the release profiles were studied. Franz diffusion cells were used to assess the release kinetic over a period of 24 h. Within the first 6 h retinol SLN displayed controlled release. After longer periods (12-24 h) the release rate increased and even exceeded the release rate of comparable nanoemulsions. Pure SLN dispersions are characterised by low viscosity. In contrast to membranous vesicles, SLN can also be stably incorporated in convenient topical dosage forms like hydrogels or creams. In the Franz diffusion cell these preparations showed a controlled release over 12-18 h. Similar to SLN dispersions an increase in release rate over a 24-h period was found. A good correlation between polymorphic transitions and increased drug release was observed in this study. Sustained release was often related to the metastable beta' polymorph. Drug expulsion is explained by a reduction of amorphous regions in the carrier lattice due to a beta'-->beta(i) polymorphic transition. This transformation can be controlled with surfactant mixtures or, in the case of the hydrogel and oil/water cream, with humectants or gelling agents. Thus, the release rate for the topical Route of Application is adjustable.
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vitamin a loaded solid lipid nanoparticles for topical use drug release properties
Journal of Controlled Release, 2000Co-Authors: Volkhard Jenning, Monika Schaferkorting, Sven GohlaAbstract:Abstract Burst release as well as sustained release has been reported for SLN suspensions. For dermal Application, both features are of interest. Burst release can be useful to improve the penetration of a drug. Sustained release becomes important with active ingredients that are irritating at high concentrations or to supply the skin over a prolonged period of time with a drug. Glyceryl behenate SLN were loaded with vitamin A and the release profiles were studied. Franz diffusion cells were used to assess the release kinetic over a period of 24 h. Within the first 6 h retinol SLN displayed controlled release. After longer periods (12–24 h) the release rate increased and even exceeded the release rate of comparable nanoemulsions. Pure SLN dispersions are characterised by low viscosity. In contrast to membranous vesicles, SLN can also be stably incorporated in convenient topical dosage forms like hydrogels or creams. In the Franz diffusion cell these preparations showed a controlled release over 12–18 h. Similar to SLN dispersions an increase in release rate over a 24-h period was found. A good correlation between polymorphic transitions and increased drug release was observed in this study. Sustained release was often related to the metastable β′ polymorph. Drug expulsion is explained by a reduction of amorphous regions in the carrier lattice due to a β′→βi polymorphic transition. This transformation can be controlled with surfactant mixtures or, in the case of the hydrogel and oil/water cream, with humectants or gelling agents. Thus, the release rate for the topical Route of Application is adjustable.
Volkhard Jenning - One of the best experts on this subject based on the ideXlab platform.
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vitamin a loaded solid lipid nanoparticles for topical use drug release properties
Journal of Controlled Release, 2000Co-Authors: Volkhard Jenning, Monika Schaferkorting, Sven GohlaAbstract:Burst release as well as sustained release has been reported for SLN suspensions. For dermal Application, both features are of interest. Burst release can be useful to improve the penetration of a drug. Sustained release becomes important with active ingredients that are irritating at high concentrations or to supply the skin over a prolonged period of time with a drug. Glyceryl behenate SLN were loaded with vitamin A and the release profiles were studied. Franz diffusion cells were used to assess the release kinetic over a period of 24 h. Within the first 6 h retinol SLN displayed controlled release. After longer periods (12-24 h) the release rate increased and even exceeded the release rate of comparable nanoemulsions. Pure SLN dispersions are characterised by low viscosity. In contrast to membranous vesicles, SLN can also be stably incorporated in convenient topical dosage forms like hydrogels or creams. In the Franz diffusion cell these preparations showed a controlled release over 12-18 h. Similar to SLN dispersions an increase in release rate over a 24-h period was found. A good correlation between polymorphic transitions and increased drug release was observed in this study. Sustained release was often related to the metastable beta' polymorph. Drug expulsion is explained by a reduction of amorphous regions in the carrier lattice due to a beta'-->beta(i) polymorphic transition. This transformation can be controlled with surfactant mixtures or, in the case of the hydrogel and oil/water cream, with humectants or gelling agents. Thus, the release rate for the topical Route of Application is adjustable.
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vitamin a loaded solid lipid nanoparticles for topical use drug release properties
Journal of Controlled Release, 2000Co-Authors: Volkhard Jenning, Monika Schaferkorting, Sven GohlaAbstract:Abstract Burst release as well as sustained release has been reported for SLN suspensions. For dermal Application, both features are of interest. Burst release can be useful to improve the penetration of a drug. Sustained release becomes important with active ingredients that are irritating at high concentrations or to supply the skin over a prolonged period of time with a drug. Glyceryl behenate SLN were loaded with vitamin A and the release profiles were studied. Franz diffusion cells were used to assess the release kinetic over a period of 24 h. Within the first 6 h retinol SLN displayed controlled release. After longer periods (12–24 h) the release rate increased and even exceeded the release rate of comparable nanoemulsions. Pure SLN dispersions are characterised by low viscosity. In contrast to membranous vesicles, SLN can also be stably incorporated in convenient topical dosage forms like hydrogels or creams. In the Franz diffusion cell these preparations showed a controlled release over 12–18 h. Similar to SLN dispersions an increase in release rate over a 24-h period was found. A good correlation between polymorphic transitions and increased drug release was observed in this study. Sustained release was often related to the metastable β′ polymorph. Drug expulsion is explained by a reduction of amorphous regions in the carrier lattice due to a β′→βi polymorphic transition. This transformation can be controlled with surfactant mixtures or, in the case of the hydrogel and oil/water cream, with humectants or gelling agents. Thus, the release rate for the topical Route of Application is adjustable.
Monika Schaferkorting - One of the best experts on this subject based on the ideXlab platform.
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vitamin a loaded solid lipid nanoparticles for topical use drug release properties
Journal of Controlled Release, 2000Co-Authors: Volkhard Jenning, Monika Schaferkorting, Sven GohlaAbstract:Burst release as well as sustained release has been reported for SLN suspensions. For dermal Application, both features are of interest. Burst release can be useful to improve the penetration of a drug. Sustained release becomes important with active ingredients that are irritating at high concentrations or to supply the skin over a prolonged period of time with a drug. Glyceryl behenate SLN were loaded with vitamin A and the release profiles were studied. Franz diffusion cells were used to assess the release kinetic over a period of 24 h. Within the first 6 h retinol SLN displayed controlled release. After longer periods (12-24 h) the release rate increased and even exceeded the release rate of comparable nanoemulsions. Pure SLN dispersions are characterised by low viscosity. In contrast to membranous vesicles, SLN can also be stably incorporated in convenient topical dosage forms like hydrogels or creams. In the Franz diffusion cell these preparations showed a controlled release over 12-18 h. Similar to SLN dispersions an increase in release rate over a 24-h period was found. A good correlation between polymorphic transitions and increased drug release was observed in this study. Sustained release was often related to the metastable beta' polymorph. Drug expulsion is explained by a reduction of amorphous regions in the carrier lattice due to a beta'-->beta(i) polymorphic transition. This transformation can be controlled with surfactant mixtures or, in the case of the hydrogel and oil/water cream, with humectants or gelling agents. Thus, the release rate for the topical Route of Application is adjustable.
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vitamin a loaded solid lipid nanoparticles for topical use drug release properties
Journal of Controlled Release, 2000Co-Authors: Volkhard Jenning, Monika Schaferkorting, Sven GohlaAbstract:Abstract Burst release as well as sustained release has been reported for SLN suspensions. For dermal Application, both features are of interest. Burst release can be useful to improve the penetration of a drug. Sustained release becomes important with active ingredients that are irritating at high concentrations or to supply the skin over a prolonged period of time with a drug. Glyceryl behenate SLN were loaded with vitamin A and the release profiles were studied. Franz diffusion cells were used to assess the release kinetic over a period of 24 h. Within the first 6 h retinol SLN displayed controlled release. After longer periods (12–24 h) the release rate increased and even exceeded the release rate of comparable nanoemulsions. Pure SLN dispersions are characterised by low viscosity. In contrast to membranous vesicles, SLN can also be stably incorporated in convenient topical dosage forms like hydrogels or creams. In the Franz diffusion cell these preparations showed a controlled release over 12–18 h. Similar to SLN dispersions an increase in release rate over a 24-h period was found. A good correlation between polymorphic transitions and increased drug release was observed in this study. Sustained release was often related to the metastable β′ polymorph. Drug expulsion is explained by a reduction of amorphous regions in the carrier lattice due to a β′→βi polymorphic transition. This transformation can be controlled with surfactant mixtures or, in the case of the hydrogel and oil/water cream, with humectants or gelling agents. Thus, the release rate for the topical Route of Application is adjustable.
Tilahun Teklehaymanot - One of the best experts on this subject based on the ideXlab platform.
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An ethnobotanical survey of medicinal and edible plants of Yalo Woreda in Afar regional state, Ethiopia
Journal of Ethnobiology and Ethnomedicine, 2017Co-Authors: Tilahun TeklehaymanotAbstract:Background The Afar people inhabit the sub-arid and arid part of Ethiopia. Recurrent drought and invasive encroaching plants are taking out plants that have cultural importance, and threaten the biodiversity and the associated traditional knowledge. Thus, the aim of the current study is to conduct an ethnobotanical survey and document medicinal and edible plants in Yalo Woreda in Afar regional state. Methods A cross-sectional ethnobotanical study was carried out in eight kebeles of Yalo Woreda from October 2015 to December 2016. One hundred sixty informants were selected using purposive sampling. The data on diseases, medicinal and edible plants were collected using semi-structure interview and group discussion. The statistical methods, informant consensus factor, fidelity level, and preference ranking were conducted to analyze the data. Results One hundred and six plants were reported; gender and age differences had implication on the number of plants reported by informants. The knowledge of medicinal plants among informants of each kebele was not different (p < 0.5) and was not associated in particular with the religious establishment in the kebeles (informant*kebeles, Eta square = 0.19). Family Fabaceae was the major plant species, and shrubs (44%) were dominant plants reported. Leaf (52.94%) and oral (68%) were primary plant part used for remedy preparation and Route of Application, respectively. The plants with low fidelity values Indigofera articulata (0.25), Cadaba farinosa (0.22), Cadaba rotundifolia (0.19), and Acalypha fruticosa (0.15) were used to treat the category of diseases with high informant consensus value (0.69). Sixteen edible plants were identified that were consumed during wet and dry seasons. Balanites aegyptiaca, Balanites rotundifolia, and Dobera glabra were ‘famine food’ that were collected and stored for years. Conclusion People in Yalo Woreda are more dependent on natural resources of the area for their livelihood. The threat of climatic change and encroaching invasive plants on medicinal and edible plants affects the traditional use of plants in the Yalo Woreda. The conservation of the plants in the home garden and natural habitat and integration of edible plants into agroforestry development programs in sub-arid and arid regions has to be encouraged to conserve plants of medical and economic importance.
Frye Michaela - One of the best experts on this subject based on the ideXlab platform.
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Considerations for skin carcinogenesis experiments using inducible transgenic mouse models
'Organisation for Economic Co-Operation and Development (OECD)', 2018Co-Authors: Popis, Martyna C, Wagner, Rebecca E, Constantino-casas Fernando, Blanco Sandra, Frye MichaelaAbstract:Abstract Objective This study was designed to estimate the percentage of non-malignant skin tumours (papillomas) progressing to malignant squamous cell carcinomas (SCCs) in a carcinogenesis study using established transgenic mouse models. In our skin cancer model, we conditionally induced oncogenic point mutant alleles of p53 and k-ras in undifferentiated, basal cells of the epidermis. Results Upon activation of the transgenes through administration of tamoxifen, the vast majority of mice (> 80%) developed skin papillomas, yet primarily around the mouth. Since these tumours hindered the mice eating, they rapidly lost weight and needed to be culled before the papillomas progressed to SCCs. The mouth papillomas formed regardless of the Route of Application, including intraperitoneal injections, local Application to the back skin, or subcutaneous insertion of a tamoxifen pellet. Implantation of a slow releasing tamoxifen pellet into 18 mice consistently led to papilloma formation, of which only one progressed to a malignant SCC. Thus, the challenges for skin carcinogenesis studies using this particular cancer mouse model are low conversion rates of papillomas to SCCs and high frequencies of mouth papilloma formation
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Considerations for skin carcinogenesis experiments using inducible transgenic mouse models.
'Organisation for Economic Co-Operation and Development (OECD)', 2018Co-Authors: Popis Martyna, Constantino-casas Fernando, Blanco Sandra, Wagner Rebecca, Frye MichaelaAbstract:Objective This study was designed to estimate the percentage of non-malignant skin tumours (papillomas) progressing to malignant squamous cell carcinomas (SCCs) in a carcinogenesis study using established transgenic mouse models. In our skin cancer model, we conditionally induced oncogenic point mutant alleles of p53 and k-ras in undifferentiated, basal cells of the epidermis. Results Upon activation of the transgenes through administration of tamoxifen, the vast majority of mice (>80%) developed skin papillomas, yet primarily around the mouth. Since these tumours hindered the mice eating, they rapidly lost weight and needed to be culled before the papillomas progressed to SCCs. The mouth papillomas formed regardless of the Route of Application, including intraperitoneal injections, local Application to the back skin, or subcutaneous insertion of a tamoxifen pellet. Implantation of a slow releasing tamoxifen pellet into 18 mice consistently led to papilloma formation, of which only one progressed to a malignant SCC. Thus, the challenges for skin carcinogenesis studies using this particular cancer mouse model are low conversion rates of papillomas to SCCs and high frequencies of mouth papilloma formation.This work was funded by Cancer Research UK (C10701/A15181), Worldwide Cancer Research (15-0168), and the Medical Research Council (MR/M01939X/1)
