Preparation and characterization of bupivacaine multivesicular liposome: A QbD study about the effects of formulation and process on critical quality attributes.

This study extends QbD principles to liposomal products containing a hydrophilic active pharmaceutical ingredient (API). The feasibility and advantages of the QbD concept for multivesicular liposome-based systems were demonstrated. We selected the local anesthetic drug bupivacaine as a model compound. Desired properties for three critical attributes of multivesicular liposome drug products, namely, the particle size, morphology, and drug encapsulation efficiency, were defined and evaluated. The liposome preparation process significantly affected both the liposome particle size and drug encapsulation efficiency. In this study, the effects of material attributes and processing parameters during the preparation of liposomes were studied in detail using a microscope and particle size analyzer. We used risk assessment to monitor several factors that substantially affect the encapsulation rate and particle size.