Documents disponibles écrits par cet auteur

Pharmaceutical salt formation guided by phase diagrams / Ka W. Lam in Industrial & engineering chemistry research, Vol. 49 N° 24 (Décembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12503-12512 Titre : Pharmaceutical salt formation guided by phase diagrams Type de document : texte imprimé Auteurs : Ka W. Lam, Auteur ; Jinjie Xu, Auteur ; Ka M. Ng, Auteur Année de publication : 2011 Article en page(s) : pp. 12503-12512 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Phase  diagram Résumé : Salt formation is frequently employed to improve the solubility and bioavailability of pharmaceutical compounds. Solid-liquid equilibrium (SLE) phase diagram that serves as the foundation for designing crystallization-based separation is introduced to facilitate the recovery of the desired salt form. Two poorly water-soluble drugs, each with two ionizable groups, were selected to demonstrate this phase diagram-guided approach. The first is pemetrexed with confirmed monosodium and disodium salt forms. The second drug is the orally administered dapsone for which no known salt form has been established. Dihydrochloric salt of dapsone was successfully formed alongside the experimental phase diagram. Its solubility was found to be 80 times higher than that of the parent drug. Caco-2 cell assays showed that the intestinal permeability of the dihydrochloric salt was as good as that of the parent drug, thus confirming the usefulness of the salt form. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23692005 [article] Pharmaceutical salt formation guided by phase diagrams [texte imprimé] / Ka W. Lam, Auteur ; Jinjie Xu, Auteur ; Ka M. Ng, Auteur . - 2011 . - pp. 12503-12512. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12503-12512 Mots-clés : Phase  diagram Résumé : Salt formation is frequently employed to improve the solubility and bioavailability of pharmaceutical compounds. Solid-liquid equilibrium (SLE) phase diagram that serves as the foundation for designing crystallization-based separation is introduced to facilitate the recovery of the desired salt form. Two poorly water-soluble drugs, each with two ionizable groups, were selected to demonstrate this phase diagram-guided approach. The first is pemetrexed with confirmed monosodium and disodium salt forms. The second drug is the orally administered dapsone for which no known salt form has been established. Dihydrochloric salt of dapsone was successfully formed alongside the experimental phase diagram. Its solubility was found to be 80 times higher than that of the parent drug. Caco-2 cell assays showed that the intestinal permeability of the dihydrochloric salt was as good as that of the parent drug, thus confirming the usefulness of the salt form. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23692005

Product Design / Yuen S. Cheng in Industrial & engineering chemistry research, Vol. 49 N° 10 (Mai 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4904–4913 Titre : Product Design : a Transdermal Patch Containing a Traditional Chinese Medicinal Tincture Type de document : texte imprimé Auteurs : Yuen S. Cheng, Auteur ; Ka M. Ng, Auteur ; Christianto Wibowo, Auteur Année de publication : 2010 Article en page(s) : pp. 4904–4913 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Transdermal  Patch Résumé : The traditional Chinese medicinal tincture is inconvenient to use and has strong herbal smells. It is highly desirable to convert such a tincture product into a transdermal patch. This study aims to design such a transdermal patch using an integrative approach. The tasks of market study, product design, prototyping, and process design were considered. Specifically, customers’ needs were collected from market study to identify the quality factors of the new product, which were, in turn, translated into the basic product configuration and technical specifications. Compatibility tests and diffusion experiments were carried out for material screening and performance testing. The procedure for fabricating the transdermal patch was also developed. Finally, a manufacturing process was proposed based on the laboratory-scale fabrication procedure. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901554s [article] Product Design : a Transdermal Patch Containing a Traditional Chinese Medicinal Tincture [texte imprimé] / Yuen S. Cheng, Auteur ; Ka M. Ng, Auteur ; Christianto Wibowo, Auteur . - 2010 . - pp. 4904–4913. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 10 (Mai 2010) . - pp. 4904–4913 Mots-clés : Transdermal  Patch Résumé : The traditional Chinese medicinal tincture is inconvenient to use and has strong herbal smells. It is highly desirable to convert such a tincture product into a transdermal patch. This study aims to design such a transdermal patch using an integrative approach. The tasks of market study, product design, prototyping, and process design were considered. Specifically, customers’ needs were collected from market study to identify the quality factors of the new product, which were, in turn, translated into the basic product configuration and technical specifications. Compatibility tests and diffusion experiments were carried out for material screening and performance testing. The procedure for fabricating the transdermal patch was also developed. Finally, a manufacturing process was proposed based on the laboratory-scale fabrication procedure. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901554s

Separation and purification of schisandrin B from fructus schisandrae / Ka F. Luk in Industrial & engineering chemistry research, Vol. 47 n°12 (Juin 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4193–4201 Titre : Separation and purification of schisandrin B from fructus schisandrae Type de document : texte imprimé Auteurs : Ka F. Luk, Auteur ; Kam M. Ko, Auteur ; Ka M. Ng, Auteur Année de publication : 2008 Article en page(s) : p. 4193–4201 Note générale : Bibliogr. p. 4201 Langues : Anglais (eng) Mots-clés : Schisandrin  B;  Fructus  Schisandrae;  Solid–liquid  extraction;  Adsorption-desorption Résumé : Schisandrin B (Sch B) is the most abundant and biologically active dibenzocyclooctadiene lignan present in Fructus Schisandrae (FS). It is a highly desirable ingredient for a dietary supplement. While Sch B has been isolated from FS in the laboratory, the experimental procedure was usually lengthy and the yield was relatively low. The objective of this study is to develop a process that is amenable to large-scale recovery of Sch B from FS. The process starts with solid–liquid extraction of FS by petroleum ether to yield a Sch B-containing extract, which is then purified by removing the relatively nonpolar substances, mostly fatty oils, by an adsorption–desorption step. This is followed by a chromatographic process to isolate the Sch B-enriched fraction that is then used to yield Sch B by crystallization. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071317b [article] Separation and purification of schisandrin B from fructus schisandrae [texte imprimé] / Ka F. Luk, Auteur ; Kam M. Ko, Auteur ; Ka M. Ng, Auteur . - 2008 . - p. 4193–4201. Bibliogr. p. 4201 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4193–4201 Mots-clés : Schisandrin  B;  Fructus  Schisandrae;  Solid–liquid  extraction;  Adsorption-desorption Résumé : Schisandrin B (Sch B) is the most abundant and biologically active dibenzocyclooctadiene lignan present in Fructus Schisandrae (FS). It is a highly desirable ingredient for a dietary supplement. While Sch B has been isolated from FS in the laboratory, the experimental procedure was usually lengthy and the yield was relatively low. The objective of this study is to develop a process that is amenable to large-scale recovery of Sch B from FS. The process starts with solid–liquid extraction of FS by petroleum ether to yield a Sch B-containing extract, which is then purified by removing the relatively nonpolar substances, mostly fatty oils, by an adsorption–desorption step. This is followed by a chromatographic process to isolate the Sch B-enriched fraction that is then used to yield Sch B by crystallization. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie071317b