title: The influence of co-formers on the dissolution rates of co-amorphous sulfamerazine/excipient systems.
abstract: A comprehensive study on the dissolution properties of three co-amorphous sulfamerazine/excipient systems, namely sulfamerazine/deoxycholic acid, sulfamerazine/citric acid and sulfamerazine/sodium taurocholate (SMZ/DA, SMZ/CA and SMZ/NaTC; 1:1 molar ratio), is reported. While all three co-formers stabilize the amorphous state during storage, only co-amorphization with NaTC provides a dissolution advantage over crystalline SMZ and the reasons for this were analyzed. In the case of SMZ/DA extensive gelation of DA protects the amorphous phase from crystallization upon contact with buffer, but at the same time prevents the release of SMZ into solution. Disk dissolution studies showed an improved dissolution behavior of SMZ/CA compared to crystalline SMZ. However, enhanced dissolution properties were not seen in powder dissolution testing due to poor dispersibility. Co-amorphization of SMZ and NaTC resulted in a significant increase in dissolution rate, both in powder and disk dissolution studies.
authors.affiliation: School of Chemistry, National University of Ireland, Galway, Ireland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Gniado
authors.affiliation: Department of Pharmacy, University of Copenhagen, Copenhagen 2100, Denmark.
authors.forename: Korbinian
authors.initials: K
authors.lastname: Löbmann
authors.affiliation: Department of Pharmacy, University of Copenhagen, Copenhagen 2100, Denmark.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rades
authors.affiliation: School of Chemistry, National University of Ireland, Galway, Ireland. Electronic address: andrea.erxleben@nuigalway.ie.
authors.forename: Andrea
authors.initials: A
authors.lastname: Erxleben
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry; D002626:Chemistry, Pharmaceutical; D019343:Citric Acid / Q000737:chemistry*; D003460:Crystallization; D003840:Deoxycholic Acid / Q000737:chemistry*; D005079:Excipients / Q000737:chemistry*; D012995:Solubility; D013416:Sulfamerazine / Q000737:chemistry*; D013656:Taurocholic Acid / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D005079:Excipients; D003840:Deoxycholic Acid; D019343:Citric Acid; D013656:Taurocholic Acid; D013416:Sulfamerazine
keywords: Co-amorphization; Dispersibility; Dissolution studies; Sulfamerazine