Pharmaceutical patent applications in freeze-drying.
Injectable products are often the formulation of choice for new therapeutics; however, formulation in liquids often enhances degradation through hydrolysis. Thus, freeze-drying (lyophilization) is regularly used in pharmaceutical manufacture to reduce water activity. Here we examine its contribution to 'state of the art' and look at its future potential uses. A comprehensive search of patent databases was conducted to characterize the international patent landscape and trends in the use of freeze-drying. A total of 914 disclosures related to freeze-drying, lyophilization or drying of solid systems in pressures and temperatures equivalent to those of freeze-drying were considered over the period of 1992-2014. Current applications of sublimation technology were contrasted across two periods those with patents due to expire (1992-1993) and those currently filed. The number of freeze-drying technology patents has stabilized after initial activity across the biotechnology sector in 2011 and 2012. Alongside an increasing trend for patent submissions, freeze-drying submissions have slowed since 2002 and is indicative of a level of maturity.
School of Pharmacy, Aston University, Birmingham, UK.
Edmond
E
Ekenlebie
Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia.
Tomaž
T
Einfalt
Faculty of Pharmaceutical Chemistry & Technology, University of Pavia, Pavia, Italy.
Arianna Irò
AI
Karytinos
AJI Technology, Leeds, UK.
Andrew
A
Ingham
D004339:Drug Compounding / Q000379:methods; D005612:Freeze Drying / Q000379:methods* / Q000639:trends*; D006801:Humans; D010330:Patents as Topic / Q000706:statistics & numerical data*
batch production; continuous; freeze-drying; lyophilization; lyoprotectant; solvent systems