title: Insights into the influence of the cooling profile on the reconstitution times of amorphous lyophilized protein formulations.
abstract: Lyophilized protein formulations must be reconstituted back into solution prior to patient administration and in this regard long reconstitution times are not ideal. The factors that govern reconstitution time remain poorly understood. The aim of this research was to understand the influence of the lyophilization cooling profile (including annealing) on the resulting cake structure and reconstitution time. Three protein formulations (BSA 50mg/ml, BSA 200mg/ml and IgG1 40mg/ml, all in 7% w/v sucrose) were investigated after cooling at either 0.5°C/min, or quench cooling with liquid nitrogen with/without annealing. Significantly longer reconstitution times were observed for the lower protein concentration formulations following quench cool. Porosity measurements found concomitant increases in the surface area of the porous cake structure but a reduction in total pore volume. We propose that slow reconstitution results from either closed pores or small pores impeding the penetration of water into the lyophilized cake.
authors.affiliation: Laboratory of Biophysics and Surface Analysis, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Beech
authors.affiliation: Formulation Sciences, MedImmune Ltd., Aaron Klug Building, Granta Park, Cambridge CB21 6GH, UK.
authors.forename: James G
authors.initials: JG
authors.lastname: Biddlecombe
authors.affiliation: Formulation Sciences, MedImmune Ltd., Aaron Klug Building, Granta Park, Cambridge CB21 6GH, UK.
authors.forename: Christopher F
authors.initials: CF
authors.lastname: van der Walle
authors.affiliation: Department of Chemical & Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Lee A
authors.initials: LA
authors.lastname: Stevens
authors.affiliation: Department of Chemical & Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Rigby
authors.affiliation: Laboratory of Biophysics and Surface Analysis, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Burley
authors.affiliation: Laboratory of Biophysics and Surface Analysis, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK. Electronic address: stephanie.allen@nottingham.ac.uk.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Allen
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry*; D004339:Drug Compounding; D004355:Drug Stability; D005612:Freeze Drying; D006358:Hot Temperature / Q000009:adverse effects; D007074:Immunoglobulin G / Q000737:chemistry*; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D008958:Models, Molecular; D016062:Porosity; D055550:Protein Stability; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D012995:Solubility; D012996:Solutions; D013499:Surface Properties; D014867:Water / Q000032:analysis
chemical_list: D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D012996:Solutions; D014867:Water; D012710:Serum Albumin, Bovine
keywords: Annealing; Lyophilization; Mercury intrusion porosimetry; Monoclonal antibody; Quench cooling; Reconstitution