The Experts below are selected from a list of 603 Experts worldwide ranked by ideXlab platform
Hajime Kojima - One of the best experts on this subject based on the ideXlab platform.
-
interlaboratory validation of the in vitro Eye Irritation Tests for cosmetic ingredients 10 evaluation of cytotoxicity test on chl cells
Toxicology in Vitro, 1999Co-Authors: H Okumura, M Arashima, J Ohuchi, Y Kasai, K Tsukumo, Hideshi Kakishima, M Kotani, Hajime Kojima, Akihiro Kurishita, M HayashiAbstract:Abstract The present interlaboratory validation study was performed in order to evaluate the use of Chinese hamster lung cell lines that employs crystal violet staining (CHL–CVS) as an alternative cytotoxicity test to the Draize Eye Irritation test (Draize test) for cosmetic ingredients. Ten substances, nine of which were surfactants, were evaluated at seven laboratories in the first phase of the validation study; 15 substances including dyes and lipids were evaluated at seven laboratories in the second phase of the validation study; 14 substances including acids and alkalis were evaluated at four laboratories in the third phase of the validation study. The logEC50 values obtained for CHL–CVS were compared with the maximal average Draize total score (MAS) for a 10% (w/v) solution of 38 cosmetic ingredients as well as isotonic sodium chloride solution. The interlaboratory coefficient of variation (CV) for EC50s was 35.6%, which was considered to be within a tolerable range. The correlation coefficient and the Spearman's rank correlation coefficient between the in vitro and in vivo Tests were −0.729 and 0.709, respectively. The prediction ability of the proposed method was assessed from the linear regression line for a MAS cut-off point of 15. According to this analysis, four substances (two alcohols and two acids) were determined to be false negative. The present study revealed the following characteristic factors of this method: (1) CHL–CVS could be applied to all the test substances including dyes and lipids in this study; (2) The results for medium-insoluble substances varied according to the laboratory; (3) The correlation between the in vivo and in vitro data for acids and alcohols (lower mono-ol) differed from that of the other substances. These results suggested that the CHL–CVS might have a potential to predict the Draize MAS if definite criteria can be established for the compounds to be applicable.
-
interlaboratory validation of the in vitro Eye Irritation Tests for cosmetic ingredients 8 evaluation of cytotoxicity Tests on sirc cells
Toxicology in Vitro, 1999Co-Authors: N Tani, N. Murakami, M Kotani, Y Okamoto, S Kinoshita, Hiroshi Itagaki, S Sugiura, M Usami, K Kato, Hajime KojimaAbstract:Abstract Two common assays, the neutral red uptake assay (SIRC–NRU) and the crystal violet staining assay (SIRC–CVS), were evaluated as alternatives to the Draize Eye Irritation test (Draize test).The cytotoxicity of thirty-eight cosmetic ingredients as well as a physiological saline solution was determined on SIRC cells at five to seven laboratories. SIRC–NRU and SIRC–CVS were performed according to the common standard operating procedure (SOP). The 50% effective concentration (EC 50 ) was determined for each ingredient. The EC 50 of SIRC–CVS was similar to that of SIRC–NRU, showing a strong correlation (r=0.995). The coefficient of variation (CV) of EC 50 which represents the interlaboratory reproducibility of SIRC–NRU was 32.1%, whereas that of SIRC–CVS was 32.8%. The logarithmically transformed EC 50 values showed a strong correlation with the maximal average Draize total score (MAS) (SIRC–NRU: r=−0.816 (n=30), SIRC–CVS: r=−0.805 (n=29)). Both methods could be applied to water-insoluble substances and dyes. However, strong acids, alkanolamines and alcohols had a tendency to deviate from the linear regression lines which were obtained from the in vivo and in vitro data for both methods in the present study. These results suggest that cytotoxicological testing on SIRC cells may provide an alternative method to the Draize test for cosmetic ingredients.
-
interlaboratory validation of in vitro Eye Irritation Tests for cosmetic ingredients 2 chorioallantoic membrane cam test
Toxicology in Vitro, 1999Co-Authors: S Hagino, Hajime Kojima, N Tani, S Kinoshita, Tsuneaki Nakamura, K Konishi, H Iimura, Y OhnoAbstract:Abstract A chorioallantoic membrane (CAM) assay evaluates the blood vessel reaction and damage to the CAM of a fertilized hen's egg. Two types of CAM assays, the hen's egg test–chorioallantoic membrane (HET–CAM) method and the chorioallantoic membrane–trypan blue staining (CAM–TB) method, were evaluated as alternative methods to the Draize Eye Irritation test (Draize test). The validation project was composed of three test phases in which 10, 15 and 14 test chemicals, respectively, were evaluated. The test procedure of the five independent laboratories was controlled under the same standard operating procedure (SOP). The interlaboratory variation was relatively high for both methods. However, the rank correlation was relatively high among the values obtained by the five laboratories. The variation associated with the CAM–TB method was smaller than that of the HET–CAM method, which requires macroscopic observation, suggesting that the objectivity and quantitativeness differs between the assay systems. The average values using these two methods were compared with the maximum average Draize total score (MAS). The correlation coefficient (r) between the HET–CAM scores and the MAS was 0.688. This suggests that a simple linear regression may not be appropriate for HET–CAM. However, the Spearman's rank correlation coefficient (rs) was relatively high (rs=0.802). In contrast, the CAM–TB test results showed a good correlation with the MAS when the test chemicals were classified according to their physical properties (r=0.801, liquid and r=0.926, powder). These results suggest that both the HET–CAM and CAM–TB methods may present alternative method of evaluation of Eye Irritation despite problems of interlaboratory reproducibility.
-
interlaboratory validation of the in vitro Eye Irritation Tests for cosmetic ingredients 3 evaluation of the haemolysis test
Toxicology in Vitro, 1999Co-Authors: Y Okamoto, J Ohuchi, Y Kasai, Hideshi Kakishima, Hajime Kojima, Hiroshi Itagaki, K Ohkoshi, T Tsuda, T Ogawa, Akihiro KurishitaAbstract:Abstract The haemolysis test using sheep red blood cells (RBC) was evaluated as an alternative method to the Draize rabbit Eye Irritation test (Draize test) by six to nine laboratories. The participating laboratories performed the test according to the standard operating procedure (SOP). Thirty-eight cosmetic ingredients and isotonic sodium chloride solution were used as test substances in this validation study. The concentrations of the test substances that induced 50% haemolysis (HC 50 value) was obtained to serve as a toxicological index and compared with in vivo Draize scores. HC 50 values were not obtained for coloured or water-insoluble (turbid) substances. Three acids caused denaturation of haemoglobin leaked from RBC and consequently interfered with the determination of the HC 50 value. Interlaboratory reproducibility was relatively good except in the case of water-insoluble substances. The average values of coefficient of variation (CV) was 37%. The correlation coefficient and Spearman's rank correlation between the HC 50 value and maximum average Draize total score (MAS) were −0.631 and 0.641, respectively. The equivalence ratio between the haemolysis test and MAS was 70.0% when MAS 15 was set as the in vivo cut-off point. On the other hand, strong irritants (MAS⩾50) could be correctly classified by this method. These results suggest that the haemolysis test might be applied to cosmetic ingredients as a screening method to distinguish strong irritants that directly affect the cell membrane permeability and do not disturb spectrophotometrical determination of haemoglobin. In order to evaluate the potential for Eye Irritation of cosmetic ingredients, a combination of haemolysis with other methods based on different mechanism should be employed to improve the predictability.
Yao Wang - One of the best experts on this subject based on the ideXlab platform.
-
a novel ion exchange carrier based upon liposome encapsulated montmorillonite for ophthalmic delivery of betaxolol hydrochloride
International Journal of Nanomedicine, 2017Co-Authors: Yi Huang, Qi Tao, Dongzhi Hou, Shuangyan Tian, Yanzhong Chen, Ruyi Gui, Lingling Yang, Yao WangAbstract:As a novel ion-exchange carrier with high surface area and excellent exchangeability, montmorillonite (Mt) was intercalated with betaxolol hydrochloride (BH) to form a nanocomposite and then encapsulated by liposomes (Mt-BH-LPs) for an ophthalmic drug-delivery system. The Mt-BH and Mt-BH-LPs were prepared by an acidification process and ethanol injection combined with ammonium sulfate gradient methods. The successful formation of Mt-BH and Mt-BH-LPs was verified by thermogravimetric analysis, X-ray diffraction, Fourier-transform infrared spectra, and transmission electron microscopy. Mt-BH-LPs possessed the favorable physical characteristics of encapsulation efficiency, drug loading, mean particle size, and ζ-potential. In vitro release studies indicated Mt-BH-LPs effectively maintained a relatively sustained slow release. Immortalized human corneal epithelial cell cytotoxicity, in vivo rabbit Eye-Irritation Tests, and chorioallantoic membrane-trypan blue staining all revealed that Mt-BH-LPs had no obvious Irritation on ocular tissues. A new in vitro tear-turnover model, including inserts containing human corneal epithelial cells, was designed to evaluate the precorneal retention time of Mt-BH-LPs. The results showed that Mt-BH-LPs maintained a certain BH concentration in tear fluid for a longer period than the BH solution. In vivo precorneal retention studies also indicated Mt-BH-LPs prolonged drug retention on the ocular surface more than the BH solution. Furthermore, pharmacodynamic studies showed that Mt-BH-LPs had a prolonged effect on decreasing intraocular optical pressure in rabbits. Our results demonstrated that Mt-BH-LPs have potential as an ophthalmic delivery system.
M Hayashi - One of the best experts on this subject based on the ideXlab platform.
-
interlaboratory validation of the in vitro Eye Irritation Tests for cosmetic ingredients 10 evaluation of cytotoxicity test on chl cells
Toxicology in Vitro, 1999Co-Authors: H Okumura, M Arashima, J Ohuchi, Y Kasai, K Tsukumo, Hideshi Kakishima, M Kotani, Hajime Kojima, Akihiro Kurishita, M HayashiAbstract:Abstract The present interlaboratory validation study was performed in order to evaluate the use of Chinese hamster lung cell lines that employs crystal violet staining (CHL–CVS) as an alternative cytotoxicity test to the Draize Eye Irritation test (Draize test) for cosmetic ingredients. Ten substances, nine of which were surfactants, were evaluated at seven laboratories in the first phase of the validation study; 15 substances including dyes and lipids were evaluated at seven laboratories in the second phase of the validation study; 14 substances including acids and alkalis were evaluated at four laboratories in the third phase of the validation study. The logEC50 values obtained for CHL–CVS were compared with the maximal average Draize total score (MAS) for a 10% (w/v) solution of 38 cosmetic ingredients as well as isotonic sodium chloride solution. The interlaboratory coefficient of variation (CV) for EC50s was 35.6%, which was considered to be within a tolerable range. The correlation coefficient and the Spearman's rank correlation coefficient between the in vitro and in vivo Tests were −0.729 and 0.709, respectively. The prediction ability of the proposed method was assessed from the linear regression line for a MAS cut-off point of 15. According to this analysis, four substances (two alcohols and two acids) were determined to be false negative. The present study revealed the following characteristic factors of this method: (1) CHL–CVS could be applied to all the test substances including dyes and lipids in this study; (2) The results for medium-insoluble substances varied according to the laboratory; (3) The correlation between the in vivo and in vitro data for acids and alcohols (lower mono-ol) differed from that of the other substances. These results suggested that the CHL–CVS might have a potential to predict the Draize MAS if definite criteria can be established for the compounds to be applicable.
-
interlaboratory validation of the in vitro Eye Irritation Tests for cosmetic ingredients 1 overview of the validation study and draize scores for the evaluation of the Tests
Toxicology in Vitro, 1999Co-Authors: Y Ohno, M Hayashi, T Kaneko, T Inoue, Y Morikawa, T Yoshida, A Fujii, Mitsuteru Masuda, T Ohno, J MommaAbstract:Abstract A three-step interlaboratory validation of alternative methods to the Draize Eye Irritation test (Draize test) was conducted by the co-operation of 27 organizations including national research institutes, universities, cosmetic industries, kit suppliers and others. Twelve alternative methods were evaluated using 38 cosmetic ingredients and isotonic sodium chloride solution. Draize Tests were conducted according to the OECD guidelines using the same lot of test substances as was evaluated in the alternative Tests. Results were as follows. (1) Variation in Draize scores was large near the critical range (maximal average Draize total scores (MAS)=15–50) for the evaluation of cosmetic ingredients. (2) Interlaboratory variation was relatively small for the alternative Tests. The mean coefficients of variation (CV%) were less than 50 for all assays except for the hen's egg–chorioallantoic membrane test (HET–CAM), chorioallantoic membrane–trypan blue staining test (CAM–TB) and haemoglobin denaturation test (HD). The CV% of these three methods came into the same range as the other Tests when non-irritants were excluded from the data analysis. (3) Results for acids (pH of 10% solution 11.5) and alcohols (lower mono-ol) in cytotoxicity Tests clearly deviated from the other samples in the comparison of cytotoxicity with Draize results. (4) Pearson's correlation coefficients (r) between results from cytotoxicity Tests using serum and MAS were −0.86 to −0.92 for samples excluding acids, alkalis and alcohols. (5) When the samples were divided into liquids and powders, r of CAM–TB increased from 0.71 for all samples to 0.80 and 0.92, respectively. (6) Spearman's rank correlation coefficients between the results of alternative methods and MAS were relatively high (r>0.8) in the case of HET–CAM and CAM–TB. Those for cytotoxicity Tests were high if the data for acids, alkalis and alcohols were excluded (SIRC–CVS: r=0.945, SIRC–NRU: r=0.931, HeLa–MTT: r=0.926, CHL–CVS: r=0.880). Exclusion of data for powdered samples also increased the coefficient of HET–CAM and CAM–TB to 0.831 and 0.863, respectively. These results suggest that no single method can constitute an evaluation system applicable to all types of test substances by itself. However, several methods will be useful for the prediction of Eye Irritation potential of cosmetic ingredients if they are used with clear understanding of the characteristics of those methods.
Yi Huang - One of the best experts on this subject based on the ideXlab platform.
-
a novel ion exchange carrier based upon liposome encapsulated montmorillonite for ophthalmic delivery of betaxolol hydrochloride
International Journal of Nanomedicine, 2017Co-Authors: Yi Huang, Qi Tao, Dongzhi Hou, Shuangyan Tian, Yanzhong Chen, Ruyi Gui, Lingling Yang, Yao WangAbstract:As a novel ion-exchange carrier with high surface area and excellent exchangeability, montmorillonite (Mt) was intercalated with betaxolol hydrochloride (BH) to form a nanocomposite and then encapsulated by liposomes (Mt-BH-LPs) for an ophthalmic drug-delivery system. The Mt-BH and Mt-BH-LPs were prepared by an acidification process and ethanol injection combined with ammonium sulfate gradient methods. The successful formation of Mt-BH and Mt-BH-LPs was verified by thermogravimetric analysis, X-ray diffraction, Fourier-transform infrared spectra, and transmission electron microscopy. Mt-BH-LPs possessed the favorable physical characteristics of encapsulation efficiency, drug loading, mean particle size, and ζ-potential. In vitro release studies indicated Mt-BH-LPs effectively maintained a relatively sustained slow release. Immortalized human corneal epithelial cell cytotoxicity, in vivo rabbit Eye-Irritation Tests, and chorioallantoic membrane-trypan blue staining all revealed that Mt-BH-LPs had no obvious Irritation on ocular tissues. A new in vitro tear-turnover model, including inserts containing human corneal epithelial cells, was designed to evaluate the precorneal retention time of Mt-BH-LPs. The results showed that Mt-BH-LPs maintained a certain BH concentration in tear fluid for a longer period than the BH solution. In vivo precorneal retention studies also indicated Mt-BH-LPs prolonged drug retention on the ocular surface more than the BH solution. Furthermore, pharmacodynamic studies showed that Mt-BH-LPs had a prolonged effect on decreasing intraocular optical pressure in rabbits. Our results demonstrated that Mt-BH-LPs have potential as an ophthalmic delivery system.
Y Ohno - One of the best experts on this subject based on the ideXlab platform.
-
interlaboratory validation of in vitro Eye Irritation Tests for cosmetic ingredients 2 chorioallantoic membrane cam test
Toxicology in Vitro, 1999Co-Authors: S Hagino, Hajime Kojima, N Tani, S Kinoshita, Tsuneaki Nakamura, K Konishi, H Iimura, Y OhnoAbstract:Abstract A chorioallantoic membrane (CAM) assay evaluates the blood vessel reaction and damage to the CAM of a fertilized hen's egg. Two types of CAM assays, the hen's egg test–chorioallantoic membrane (HET–CAM) method and the chorioallantoic membrane–trypan blue staining (CAM–TB) method, were evaluated as alternative methods to the Draize Eye Irritation test (Draize test). The validation project was composed of three test phases in which 10, 15 and 14 test chemicals, respectively, were evaluated. The test procedure of the five independent laboratories was controlled under the same standard operating procedure (SOP). The interlaboratory variation was relatively high for both methods. However, the rank correlation was relatively high among the values obtained by the five laboratories. The variation associated with the CAM–TB method was smaller than that of the HET–CAM method, which requires macroscopic observation, suggesting that the objectivity and quantitativeness differs between the assay systems. The average values using these two methods were compared with the maximum average Draize total score (MAS). The correlation coefficient (r) between the HET–CAM scores and the MAS was 0.688. This suggests that a simple linear regression may not be appropriate for HET–CAM. However, the Spearman's rank correlation coefficient (rs) was relatively high (rs=0.802). In contrast, the CAM–TB test results showed a good correlation with the MAS when the test chemicals were classified according to their physical properties (r=0.801, liquid and r=0.926, powder). These results suggest that both the HET–CAM and CAM–TB methods may present alternative method of evaluation of Eye Irritation despite problems of interlaboratory reproducibility.
-
interlaboratory validation of the in vitro Eye Irritation Tests for cosmetic ingredients 1 overview of the validation study and draize scores for the evaluation of the Tests
Toxicology in Vitro, 1999Co-Authors: Y Ohno, M Hayashi, T Kaneko, T Inoue, Y Morikawa, T Yoshida, A Fujii, Mitsuteru Masuda, T Ohno, J MommaAbstract:Abstract A three-step interlaboratory validation of alternative methods to the Draize Eye Irritation test (Draize test) was conducted by the co-operation of 27 organizations including national research institutes, universities, cosmetic industries, kit suppliers and others. Twelve alternative methods were evaluated using 38 cosmetic ingredients and isotonic sodium chloride solution. Draize Tests were conducted according to the OECD guidelines using the same lot of test substances as was evaluated in the alternative Tests. Results were as follows. (1) Variation in Draize scores was large near the critical range (maximal average Draize total scores (MAS)=15–50) for the evaluation of cosmetic ingredients. (2) Interlaboratory variation was relatively small for the alternative Tests. The mean coefficients of variation (CV%) were less than 50 for all assays except for the hen's egg–chorioallantoic membrane test (HET–CAM), chorioallantoic membrane–trypan blue staining test (CAM–TB) and haemoglobin denaturation test (HD). The CV% of these three methods came into the same range as the other Tests when non-irritants were excluded from the data analysis. (3) Results for acids (pH of 10% solution 11.5) and alcohols (lower mono-ol) in cytotoxicity Tests clearly deviated from the other samples in the comparison of cytotoxicity with Draize results. (4) Pearson's correlation coefficients (r) between results from cytotoxicity Tests using serum and MAS were −0.86 to −0.92 for samples excluding acids, alkalis and alcohols. (5) When the samples were divided into liquids and powders, r of CAM–TB increased from 0.71 for all samples to 0.80 and 0.92, respectively. (6) Spearman's rank correlation coefficients between the results of alternative methods and MAS were relatively high (r>0.8) in the case of HET–CAM and CAM–TB. Those for cytotoxicity Tests were high if the data for acids, alkalis and alcohols were excluded (SIRC–CVS: r=0.945, SIRC–NRU: r=0.931, HeLa–MTT: r=0.926, CHL–CVS: r=0.880). Exclusion of data for powdered samples also increased the coefficient of HET–CAM and CAM–TB to 0.831 and 0.863, respectively. These results suggest that no single method can constitute an evaluation system applicable to all types of test substances by itself. However, several methods will be useful for the prediction of Eye Irritation potential of cosmetic ingredients if they are used with clear understanding of the characteristics of those methods.
