PT  - JOURNAL ARTICLE
AU  - Werk, Tobias
AU  - Mahler, Hanns-Christian
AU  - Ludwig, Imke Sonja
AU  - Luemkemann, Joerg
AU  - Huwyler, Joerg
AU  - Hafner, Mathias
TI  - A method to determine the kinetics of solute mixing in liquid/liquid formulation dual-chamber syringes
AID  - 10.5731/pdajpst.2016.006601
DP  - 2016 Jan 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - pdajpst.2016.006601
4099  - http://journal.pda.org/content/early/2016/08/10/pdajpst.2016.006601.short
4100  - http://journal.pda.org/content/early/2016/08/10/pdajpst.2016.006601.full
AB  - Dual chamber syringes (DCS) were originally designed to separate a solid substance and its diluent. However, they can also be used to separate liquid formulations of two individual drug products, which cannot be co-formulated due to technical or regulatory issues. A liquid/liquid dual chamber syringe can be designed to achieve homogenization and mixing of both solutions either prior to administration or it can be used to sequentially inject both solutions. While sequential injection can be easily achieved by a dual chamber syringe with a bypass located at the needle end of the syringe barrel, mixing of the two fluids may provide more challenging. Within this study, the mixing behavior of surrogate solutions in different dual-chamber syringes is assessed. Furthermore, the influence of parameters such as injection angle, injection speed, agitation, and sample viscosity were studied. It was noted that mixing was poor for the commercial DCS (with a bypass designed as a longitudinal ridge) when the two liquids significantly differ in their physical properties (viscosity, density). However, an optimized DCS design with multiple bypass channels resulted in improved mixing of liquids.