No abstract

When complex biological materials are analyzed without an adequate sample preparation technique, MS signal and response undergo significant alteration and result in poor quantification and assay. This problem generally takes place due to the presence of several endogenous materials component in samples. One of the major causes of ion suppression in bioanalysis is the presence of phospholipids during LC-MS analysis. The phospholipid-based matrix effect was investigated with a commercially available electro spray ionization (ESI) source coupled with a triple quadrupole mass spectrometer. HybridSPE dramatically reduced the levels of residual phospholipids in biological samples, leading to significant reduction in matrix effects. This new procedure that combines the simplicity of precipitation with the selectivity of SPE allows obtaining much cleaner extracts than with conventional procedures. HybridSPE-precipitation procedure provides significant improvement in bioanalysis and a practical and fast way to ensure the avoidance of phospholipids-based matrix effects. The present review outlines the HybridSPE technique to minimize phospholipids-based matrix effects on LC–ESI-MS bioanalysis.

Combination therapy of artemether (ART) and lumefantrine (LUM) is well-established for the treatment of uncomplicated malaria worldwide. Nanoliposomes (NLs) encapsulating both drugs were prepared and freeze-dried. The lyophilized nanoliposomes exhibited high entrapment efficiency of artemether (66.18%), relatively low entrapment efficiency of lumefantrine (53.46%), low average size diameter (125.3 nm) and found to be stable at 4 °C for 60 days without significant change in mean particle diameter and drug entrapment efficiencies. In vitro drug release study has shown initial burst effect and then sustained release pattern over a time period of 30 h. In vivo toxicity study was examined by liver and kidney function test as well as histopathological examination. Nanoliposomes showed lower hemolytic potential (∼10%) compared to all the components when studied individually. There was no significant change (p > 0.05) in biochemical parametes between control and treated group of animals. Pharmacokinetic data of ART + LUM NLs showed higher the area under the plasma concentration-time curve (AUC) values and prolonged residence time of drug in the blood circulation compared with ART + LUM solution. The tissue distribution demonstrated high uptake of ART + LUM-NLs in RES organs particularly in liver and spleen. Biocompatibility was confirmed by hepato- and nephrotoxicity analysis showed no sign of fibrosis, fatty infiltration, centrilobular necrosis and lymphocyte infiltration confirmed the suitability of developed formulation for treatment of malaria.