Exploring temozolomide encapsulated PEGylated liposomes and lyotropic liquid crystals for effective treatment of glioblastoma: in-vitro, cell line, and pharmacokinetic studies.

Temozolomide (TMZ) is one of the best choices for treating glioblastoma. However, due to the short plasma half-life, only 20-30 % brain bioavailability can be achieved using traditional formulations. In the present study, PEGylated liposomes and lyotropic liquid crystals (LLCs) were developed and investigated to prolong the plasma circulation time of TMZ. Industrially feasible membrane extrusion and modified hot melt emulsification techniques were utilized during the formulation. Liposomes and LLCs in the particle size range of 80-120 nm were obtained with up to 50 % entrapment efficiency. The nanocarriers were found to show a prolonged release of up to 72 h. The cytotoxicity studies in glioblastoma cell lines revealed a ∼1.6-fold increased cytotoxicity compared to free TMZ. PEGylated liposomes and PEGylated LLCs were found to show a 3.47 and 3.18-fold less cell uptake in macrophage cell lines than uncoated liposomes and LLCs, respectively. A 1.25 and 2-fold increase in the plasma t was observed with PEGylated liposomes and PEGylated LLCs, respectively, compared to the TMZ when administered intravenously. Extending plasma circulation time of TMZ led to significant increase in brain bioavailability. Overall, the observed improved pharmacokinetics and biodistribution of TMZ revealed the potential of these PEGylated nanocarriers in the efficient treatment of glioblastoma.