Bio-evaluation of Poly-Lactate co-Glycolic Acid (PLGA) nanoparticles loaded with radio-labeled rifampicin.

The poly lactate co-glycolic acid (PLGA) nanoparticles of tubercular drugs have been demonstrated to have sustained release profile over seven days. There is no information on the location or mode of release of these nanoparticles in living system. Therefore, we have planned the study to explore the pharmacokinetics and biodistribution of PLGA rifampicin nanoparticles in healthy human volunteers. Rifampicin was labeled with 99mTc by indirect method and nanoparticles were prepared by a single emulsion evaporation method. To investigate the pharmacokinetics and biodistribution of nanoparticles, a single dose of 450 mg of rifampicin was administered orally to healthy human volunteers divided into two different groups. Following a single oral dosage of the rifampicin nanoformulation, the PK parameters were significantly different between the nanoparticle and conventional groups AUC (113.8 vs 58.6), MRT (16.2 vs 5.8) and Ke (0.04 vs 0.10). Also SPECT/CT images revealed bio-distrubution of nanoparticles in the distal portions of the intestine, which is consistent with our dosimetry analysis Significant difference in PK parameters and bio-distribution of nanoparticles in spleen and lymph nodes with maximum deposition were observed in large intestine. Nanoparticle distribution pattern may be advantageous for the treatment of intestinal or lymph node TB and has the potential to result in a lower dose of rifampicin nanoformulation for the treatment of pulmonary TB.