Category: Formulation and Quality
Purpose: In this study we evaluated the effectiveness of different strategies for mitigating the host cell protein mediated hydrolysis of polysorbate in Drug product formulations, and evaluated the effectiveness of these strategies at minimizing or preventing the formation of insoluble fatty acid aggregates.
Methods: Several formulations were prepared using a Drug product batch known to contain esterase activity. Different qualities (multi compendial, super refined, High Lauric acid) and quantities (0.02- 0.10% w/volume) of polysorbate were tested. Other excipients such as lipase inhibitors and cyclodextrins were also tested as well as alternative surfactants such as Brij and Poloxamer 188. The formulations were placed on stability under refrigerated (2-8C°), room temperature (25C°) and stressed (40C°) storage conditions for 12 months, 6 months and 3 months respectively. At the end of each study condition formulations were shaken for 24 hours at 250 RPM on an orbital shaker to evaluate if there was enough surfactant protection to guard the API against mechanical stress.
Polysorbate and free fatty acid concentrations (when applicable) was monitored using HPLC. Particle formation was monitored using MFI, HIAC.
The drug product in each formulation was monitored for standard quality attributes using a range of assays: A280, CIEF, CSDS, SEC, Turbidity.
Results: Altering quantity of polysorbate in a formulation was shown to have an impact on the timing of particle formation, where formulations with higher concentrations of polysorbate required more time to develop insoluble aggregates. Alternative surfactants such as Bridge and Poloxamer 188 proved to be effective substitutes for polysorbate 20. The addition of a lipase inhibitor both prevented polysorbate hydrolysis and FFA particle formation while the addition of did not prevent they hydrolysis of polysorbate but did prevent FFA particle formation.
Conclusion: Depending on the stage of development of a Drug Product and the severity of the esterase activity some mitigation strategies are more practical than others. The use of an alternative surfactant such as Brij or poloxamer 188 or the addition of a lipase inhibitor to the Drug product (or to an incubation step during early purification) are the most effective strategies for preventing the formulation of free fatty acid aggregates. Drug products with mild esterase activity can delay the onset of fatty acid particle formation by elevating the concentration of polysorbate or by the inclusion of cyclodextrin.
Ashaben Patel– Malvern, Pennsylvania