In vitro Characterization and Drug Release Studies of Ethambutol-Loaded Nanoparticles for Pulmonary Delivery

The development of more effective drug delivery techniques is necessary to increase treatment efficacy and patient compliance since tuberculosis (TB) is still a serious worldwide health concern. Ethambutol is a vital aspect of TB treatment, and using nanoparticles to carry it to the lungs may provide targeted delivery and prolonged release, which might enhance the effectiveness of the treatment.

This work aimed to optimize the formulation for prolonged drug release by synthesizing and assessing ethambutol-loaded nanoparticles using the desolation technique with albumin as the polymer. Additionally, the effects of different drug-polymer ratios and stirring rates were investigated.

Nine formulations of ethambutol-loaded nanoparticles were prepared by varying the drug-polymer ratios (1:1 to 1:2) and stirring speeds (500 to 1500 rpm). Key parameters, such as particle size, drug entrapment efficiency, and zeta potential, were measured. The optimized formulation was selected based on the smallest particle size and highest drug entrapment efficiency. Scanning electron microscopy was used to analyze the surface morphology of the nanoparticles. The in vitro drug release profile of the optimized formulation was studied over 24 hours.

Increasing the drug-polymer ratio from 1:1 to 1:2 increased nanoparticle size from 192.1 nm to 605.06 nm and decreased drug entrapment efficiency from 75.7%±0.08 to 34%±0.06. Higher stirring speeds (500 to 1500 rpm) also led to larger particle sizes and reduced drug entrapment due to polymer self-aggregation. Zeta potential values ranged from -5.56 to -25.6 mV. Scanning electron microscopy confirmed smooth, spherical nanoparticles. The optimized formulation, EN-5, exhibited the smallest particle size and highest drug entrapment efficiency. In vitro drug release studies showed a sustained ethambutol release, with 42.66±1.53% released in 12 hours and 79.082±2.98% in 24 hours.

Ethambutol-loaded nanoparticles having the ability to transport drugs to the lungs over an extended period of time were developed and optimized in the study. With improved drug delivery systems, the optimized formulation showed notable drug entrapment efficiency and controlled release, suggesting its potential to improve tuberculosis therapy.