title: Physicochemical characterization of commercial freeze-dried snake antivenoms.
abstract: Freeze-drying is a process used to improve the stability of pharmaceutical proteins, including snake antivenoms. This additional step confers these with a higher stability in comparison to liquid formulations, especially in tropical regions where high temperatures could affect the activity of immunoglobulins. Currently, the knowledge about freeze-drying process conditions for snake antivenoms is very limited. Some of the scarce scientific works on this subject reported reconstitution times up to 90 min for these preparations, which could imply a delay in the beginning of the antivenom therapy at the clinical setting. Therefore there is a reasonable concern about whether freeze-dried antivenoms exhibit the desired attributes for solid pharmaceutical proteins. In this work, a physicochemical characterization of seven commercial freeze-dried snake antivenoms was performed based on tests recommended by the World Health Organization (WHO). No significant differences were observed between the products regarding macroscopic appearance of the solid cakes, reconstitution times, residual humidity and monomers content. On the other hand, total protein concentration, turbidity and electrophoretic profile were different among samples. Microscopic analysis by scanning electron microscopy showed no collapsed structure and, instead, most of the samples showed a characteristic protein morphology composed of smooth plates and channels. All the parameters tested in this study were according to literature recommendations and evidenced that, in spite of slight variations found for some products, formulation and freeze-drying conditions chosen by manufacturers are adequate to prevent aggregation and generate, in physicochemical terms, freeze-dried antivenoms of acceptable quality.
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica; Sección de Química Analítica, Escuela de Química, Universidad de Costa Rica, San José, Costa Rica. Electronic address: maria.herrera_v@ucr.ac.cr.
authors.forename: María
authors.initials: M
authors.lastname: Herrera
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
authors.forename: Daniela
authors.initials: D
authors.lastname: Solano
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
authors.forename: Aarón
authors.initials: A
authors.lastname: Gómez
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
authors.forename: Mauren
authors.initials: M
authors.lastname: Villalta
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
authors.forename: Mariángela
authors.initials: M
authors.lastname: Vargas
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
authors.forename: Andrés
authors.initials: A
authors.lastname: Sánchez
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
authors.forename: José María
authors.initials: JM
authors.lastname: Gutiérrez
authors.affiliation: Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
authors.forename: Guillermo
authors.initials: G
authors.lastname: León
mesh_terms: D000997:Antivenins / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D004355:Drug Stability; D005612:Freeze Drying; D008855:Microscopy, Electron, Scanning; D055550:Protein Stability; D011786:Quality Control; D012910:Snake Venoms / Q000037:antagonists & inhibitors*; D014944:World Health Organization
chemical_list: D000997:Antivenins; D012910:Snake Venoms
keywords: Antivenom; Collapse; Freeze-drying; Protein formulation; Quality control