Documents disponibles écrits par cet auteur

Optimal solvent screening for the crystallization of pharmaceutical compounds from multisolvent systems / Ehsan Sheikholeslamzadeh in Industrial & engineering chemistry research, Vol. 51 N° 42 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13792-13802 Titre : Optimal solvent screening for the crystallization of pharmaceutical compounds from multisolvent systems Type de document : texte imprimé Auteurs : Ehsan Sheikholeslamzadeh, Auteur ; Chau-Chyun Chen, Auteur ; Sohrab Rohani, Auteur Année de publication : 2012 Article en page(s) : pp. 13792-13802 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Crystallization Résumé : In this study, an effort has been made to predict the solid―liquid equilibrium (SLE) behavior of different solids (pharmaceuticals) in many common solvents and their mixtures. A modified optimization of a recent thermodynamic model, the NRTL―SAC model, was used in all stages of calculation (VLE, LLE, and SLE predictions). The batch cooling-antisolvent crystallization process was simulated for seven model molecules from the initial temperature to the final temperature and for the volume fraction of each solvent. The feasible region of temperature for each crystallization case was calculated based on the bubble-point temperature of the solvent mixture and the melting point of the model molecules. The NRTL-SAC model was used in conjunction with the optimization procedure to test the complete miscibility of solvents during each part of crystallization. After estimating the optimum solvent mixture (combination) for a specific model molecule, the results for single, binary, and ternary solvent mixtures were compared. The results obtained from the binary and ternary combinations were similar in terms of crystallization yields per mass of solvent mixture and far superior to those obtained with single solvents. The proposed algorithm demonstrates flexibility, simplicity, and accuracy in predicting the phase behavior and eventual optimal solvent screening for the crystallization of pharmaceutical components. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26508203 [article] Optimal solvent screening for the crystallization of pharmaceutical compounds from multisolvent systems [texte imprimé] / Ehsan Sheikholeslamzadeh, Auteur ; Chau-Chyun Chen, Auteur ; Sohrab Rohani, Auteur . - 2012 . - pp. 13792-13802. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13792-13802 Mots-clés : Crystallization Résumé : In this study, an effort has been made to predict the solid―liquid equilibrium (SLE) behavior of different solids (pharmaceuticals) in many common solvents and their mixtures. A modified optimization of a recent thermodynamic model, the NRTL―SAC model, was used in all stages of calculation (VLE, LLE, and SLE predictions). The batch cooling-antisolvent crystallization process was simulated for seven model molecules from the initial temperature to the final temperature and for the volume fraction of each solvent. The feasible region of temperature for each crystallization case was calculated based on the bubble-point temperature of the solvent mixture and the melting point of the model molecules. The NRTL-SAC model was used in conjunction with the optimization procedure to test the complete miscibility of solvents during each part of crystallization. After estimating the optimum solvent mixture (combination) for a specific model molecule, the results for single, binary, and ternary solvent mixtures were compared. The results obtained from the binary and ternary combinations were similar in terms of crystallization yields per mass of solvent mixture and far superior to those obtained with single solvents. The proposed algorithm demonstrates flexibility, simplicity, and accuracy in predicting the phase behavior and eventual optimal solvent screening for the crystallization of pharmaceutical components. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26508203

Solubility prediction of pharmaceutical and chemical compounds in pure and mixed solvents using predictive models / Ehsan Sheikholeslamzadeh in Industrial & engineering chemistry research, Vol. 51 N° 1 (Janvier 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 1 (Janvier 2012) . - pp. 464-473 Titre : Solubility prediction of pharmaceutical and chemical compounds in pure and mixed solvents using predictive models Type de document : texte imprimé Auteurs : Ehsan Sheikholeslamzadeh, Auteur ; Sohrab Rohani, Auteur Année de publication : 2012 Article en page(s) : pp. 464-473 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Forecast  model  Mixed  solvent  Chemical  compound  Prediction  Solubility Résumé : Thermodynamic models offer a fast, reliable, and cost-effective method to select the best solvent or solvent mixtures for crystallization of solid components. To optimize the performance of the unit operations which produce active pharmaceutical ingredients (APIs), the physical properties of the solute and solvent must be known. Solubility prediction is very crucial in the fine and specialty chemical industries, as the total cost of production is high in most cases. In this study, the solubility of three chemical compounds, 3-pentadecylphenol, lovastatin, and valsartan, in different solvents and solvent mixtures were studied experimentally and theoretically. The thermodynamic models of the UNIFAC and the NRTL-SAC model were used for prediction. The results of the prediction from the two models and their average relative deviation for the three model compounds showed a better performance for the NRTL-SAC model compared to the UNIFAC. For the case of lovastatin and valsartan, the NRTL-SAC model gives the average relative deviation of 0.2401 and 0.3843, respectively. Because of the flexibility of the NRTL-SAC program code that is written for the phase behavior prediction, it can be used for further analysis and optimization of the performance of crystallization processes (i.e., solvent screening and yield of the process). This study shows that the NRTL-SAC model can be used effectively in pharmaceutical industry, especially for solvent screening purposes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25476490 [article] Solubility prediction of pharmaceutical and chemical compounds in pure and mixed solvents using predictive models [texte imprimé] / Ehsan Sheikholeslamzadeh, Auteur ; Sohrab Rohani, Auteur . - 2012 . - pp. 464-473. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 1 (Janvier 2012) . - pp. 464-473 Mots-clés : Forecast  model  Mixed  solvent  Chemical  compound  Prediction  Solubility Résumé : Thermodynamic models offer a fast, reliable, and cost-effective method to select the best solvent or solvent mixtures for crystallization of solid components. To optimize the performance of the unit operations which produce active pharmaceutical ingredients (APIs), the physical properties of the solute and solvent must be known. Solubility prediction is very crucial in the fine and specialty chemical industries, as the total cost of production is high in most cases. In this study, the solubility of three chemical compounds, 3-pentadecylphenol, lovastatin, and valsartan, in different solvents and solvent mixtures were studied experimentally and theoretically. The thermodynamic models of the UNIFAC and the NRTL-SAC model were used for prediction. The results of the prediction from the two models and their average relative deviation for the three model compounds showed a better performance for the NRTL-SAC model compared to the UNIFAC. For the case of lovastatin and valsartan, the NRTL-SAC model gives the average relative deviation of 0.2401 and 0.3843, respectively. Because of the flexibility of the NRTL-SAC program code that is written for the phase behavior prediction, it can be used for further analysis and optimization of the performance of crystallization processes (i.e., solvent screening and yield of the process). This study shows that the NRTL-SAC model can be used effectively in pharmaceutical industry, especially for solvent screening purposes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25476490