Exploring microfluidics and membrane extrusion for the formulation of temozolomide-loaded liposomes: investigating the effect of formulation and process variables.

Liposomes have gained much attention in drug delivery since the entry of liposomal Doxorubicin (Doxil ® ) into the market. Liposomes can entrap lipophilic, hydrophilic as well as amphiphilic drug molecules due to their distinctive structural features. Yet the clinical translation of liposomes is limited due to the reproducibility issues owing to a lack of information related to the impact of process parameters and formulation variables on designed liposomes. Recently, preparation techniques like membrane extrusion and microfluidics have been reported to produce liposomes in a reproducible manner. The present research study selected an amphiphilic drug Temozolomide (TMZ). It has a short half-life in the plasma due to its pH-dependent stability. Various critical and non-critical parameters affecting the critical quality attributes were identified and studied using risk-based assessment. The effect of various material attributes and process parameters on the critical quality attributes of the temozolomide-loaded liposomes prepared by microfluidics and membrane extrusion techniques were investigated in detail. Liposomes in the size range of 100-150 nm were targeted. Both techniques were optimized with a minimum number of critical process parameters. The obtained information will be beneficial to formulation scientists for designing liposomes for an amphiphilic drug on a large scale.