A Comparison of Protein Stability in Prefillable Syringes Made of Glass and Plastic.

The development of protein therapeutics requires stabilization of these labile molecules during shipment and storage. Biologics, particularly monoclonal antibodies, are frequently packaged at high concentration in prefillable syringes traditionally made of glass. However, some biologics are unstable in glass due to sensitivity to silicone oil, tungsten, glue, or metal ions. Syringes made from the plastic cyclic olefin polymer, Daikyo Crystal Zenith® (CZ), with a Flurotec-laminated piston, have none of these issues. This study compared the stability of several proteins including biotherapeutics when stored up to 14 months at 5 °C and 25 °C in prefillable siliconized syringes made of glass or silicone oil-free CZ syringes, and when subjected to mild agitation by end-over-end rotation at room temperature. At each time point, proteins were analyzed by several techniques including turbidity, size exclusion high-performance liquid chromatography, reversed phase high-performance liquid chromatography, ion-exchange chromatography, electrophoresis, and light scattering to monitor changes in aggregation and degradation. The results show that proteins have comparable stability when stored in glass syringes or in syringes made of CZ sterilized by E-beam or autoclave. In addition, proteins stressed by agitation were generally more stable and aggregated less in syringes made of CZ than in ones made of glass.LAY ABSTRACT: Biotherapeutic protein drugs such as monoclonal antibodies are frequently packaged at high concentration in prefillable syringes, which allows the drug to be directly administered by the patient or caregiver. Protein drugs, or biologics, can be unstable, and may aggregate, particularly when shaken. These aggregates can be immunogenic, stimulating the body's immune system to produce antibodies that can reduce the drug's efficacy. Although prefillable syringes are traditionally made of glass, some biologics are unstable in glass syringes due to the presence of substances used in their manufacture, including silicone oil, which is necessary for lubricity. Syringes made from the plastic cyclic olefin polymer, Daikyo Crystal Zenith® (CZ), have none of these issues. This study compared the stability of several biotherapeutic proteins when stored up to 14 months at 5 °C and 25 °C in prefillable siliconized syringes made of glass or silicone oil-free CZ syringes, and when mildly agitated at room temperature. Proteins were analyzed by several techniques to detect changes in aggregation and degradation. The results show that biotherapeutic proteins have similar stability whether stored in syringes made of glass or CZ. In addition, proteins subjected to agitation were generally more stable and aggregated less in CZ syringes than in glass syringes.

A quality comparison of protein crystals grown under containerless conditions generated by diamagnetic levitation, silicone oil and agarose gel.

High-quality crystals are key to obtaining accurate three-dimensional structures of proteins using X-ray diffraction techniques. However, obtaining such protein crystals is often a challenge. Several containerless crystallization techniques have been reported to have the ability to improve crystal quality, but it is unknown which is the most favourable way to grow high-quality protein crystals. In this paper, a quality comparison of protein crystals which were grown under three containerless conditions provided by diamagnetic levitation, silicone oil and agarose gel was conducted. A control experiment on a vessel wall was also simultaneously carried out. Seven different proteins were crystallized under the four conditions, and the crystal quality was assessed in terms of the resolution limit, the mosaicity and the Rmerge. It was found that the crystals grown under the three containerless conditions demonstrated better morphology than those of the control. X-ray diffraction data indicated that the quality of the crystals grown under the three containerless conditions was better than that of the control. Of the three containerless crystallization techniques, the diamagnetic levitation technique exhibited the best performance in enhancing crystal quality. This paper is to our knowledge the first report of improvement of crystal quality using a diamagnetic levitation technique. Crystals obtained from agarose gel demonstrated the second best improvement in crystal quality. The study indicated that the diamagnetic levitation technique is indeed a favourable method for growing high-quality protein crystals, and its utilization is thus potentially useful in practical efforts to obtain well diffracting protein crystals.

Development of biotechnology products in pre-filled syringes: technical considerations and approaches.

A monoclonal antibody (mAb) product development case study is presented to address some of the issues faced during developing a pre-filled syringe (PFS) product for a biotherapeutic. In particular, issues involving incompatibility with silicone oil and a stability-based approach for selection of PFS barrel and tip cap components have been discussed. Silicone spiking studies followed by exposure to agitation stress or accelerated temperature conditions were used to check for incompatibilities of the mAb with silicone oil, a necessary product contact material in PFS. In addition, screening studies to compare various closure materials as well as syringe barrel processing methods were used to select the optimum closure materials as well as the correct syringe processing method. Results indicate that the model mAb formulation used was sensitive to high levels of silicone oil especially under accelerated temperature conditions resulting in formation of protein-silicone particles in the solution for samples that were spiked with the silicone oil. Agitation stress did not have any significant impact on the quality attributes tested. Samples stored in syringe barrels that were processed with sprayed-on silicone had higher levels of subvisible particles as compared to those that were processed with the baked-on process. The tip cap comparability study resulted in one tip cap material having superior compatibility among the three that were tested. The quality attribute that was most impacted by the tip cap materials was mAb oxidation. An approach for evaluation of primary packaging components during the development of pre-filled syringe presentations for biotechnology-based compounds has been highlighted.

Particle size coarsening induced by valve silicone in a metered dose inhaler.

The objective of this study was to evaluate the effect of valve silicone on the delivered particle size distribution of a suspension metered dose inhaler (MDI). Valves were manufactured with distinct levels of silicone, which could be differentiated with Fourier transform infrared spectroscopy (FT-IR). The amount of silicone in the valve was proportional to the amount of silicone that entered the formulation and the subsequent decrease in fine particle fraction (FPF) of the active pharmaceutical ingredient (API) measured by Andersen cascade impaction. The effect of silicone content was not linear as even small amounts of silicone made a significant contribution to particle size coarsening. This coarsening was also a function of storage time and temperature. Accelerated stability conditions greatly increased coarsening kinetics as 1 month at 40 degrees C and 75% RH induced significantly more coarsening than 12 months at room temperature. Field emission scanning electron micrograph images suggest that the primary mechanism of particle size change may be aggregation as particle clusters were seen. This study indicates that silicone can be a critical process parameter for particle size distribution of a suspension MDI product. Thus, the amount of silicone in the valves needs to be minimized and controlled.