Evaluation of Physiochemical Properties of L Asparaginase Loaded Solid Lipid Nanoparticles

Abstract

The tetrameric form of L-Asparaginase (L-Asp) is a biological active form of a protein newlinewhich is a clinically approved chemotherapeutic agent used for the treatment of acute newlinelymphoblastic leukemia and lymphosarcoma by catalyzing an enzymatic reaction which newlinein turn depletes the circulating amino acid L-Asparagine and arrests the cell cycle newlinethrough inhibiting the intracellular protein synthesis. Chemotherapy is the all-time newlinepopular mainstream treatment of the ALL. L-Asp is known to produce cytocidal effect newlineon cancer cell by arresting cell cycle at G1 stage. This cell cycle arrest is reported to newlineoccur when L-Asp interferes with the normal process of protein synthesis in cancer cell newlinethrough depleting an amino acid L-Asparagine (L-Asn) circulating in the blood stream newlineand is supplied extracellularly to the cancer cell. This mechanism itself produces highly newlineselective cytocidal effect and is surprisingly very effective in the treatment of ALL. But newlinethe biggest shortcomings of the existing formulations are that the existing formulations newlinepossesses shorter in vivo half life, are more prone to its proteolytic degradation and in newlineturn its frequent administration through parenteral route. To retain the biological activity newlineof enzyme during the formulation development is also another challenge that makes the newlinetreatment incomplete. In this PhD research, a modified double emulsion (W/O/W) newlinemethod followed by solvent evaporation was used in the development of L-Asp loaded newlineSolid Lipid Nanoparticles. SLN -A Carrier Based Drug Delivery System was explored newlineto develop a new formulation system for L-Asp that would ensure a prolonged and newlinesustained drug release that also avoids proteolytic degradation of L-Asp and retaining newlineits in vivo biological activity by optimizing the parameters involved in the development newlineof SLN formulation using Box Behnken Design of Expert. All the physical, chemical newlineand biological parameters of the enzyme and drug delivery system was closely studied newlineat their interaction points so as to develop a stable and effective drug delivery system as newlineSLNs that overcomes all the challenges present in the existing delivery systems of LAsp. newlineVarious parameters were closely observed and optimized through a series of newlineexperiments like homogenization speed and time; temperature and pH during the entire newlineprocess; selection of lipid and surfactants, selection of concentration of lipid, surfactants newlineand drug. The optimized drug loaded SLN formulation was further characterized for its newlineparticle size and PDI; Zeta Potential; % Drug Entrapped; % of secondary structure newlineremains intact and in turn % Biological activity obtained; stability studies over different newlinestorage conditions; in vitro drug release profile; in vivo pharmacokinetics study; ex vivo newlinestudy of the developed drug delivery system on leukemic cell lines (MOLT-4 and Jukrat newlineE6.1). As L-Asparaginase is an enzyme and enzymes are always sensitive in newline