Spray-dried, Biodegradable, Linezolid-loaded Microspheres for Use in the Treatment of Lung Diseases

Introduction: Researchers worldwide are currently seeking innovative treatment options to combat the alarming increase in bacterial resistance to antimicrobial drugs. Staphylococcus aureus, a frequently encountered and potentially life-threatening bacterium, has become particularly problematic. Linezolid is one of the few medicines on the market that can treat bacteria resistant to other antibiotics. This is the first antibacterial oxazolidinone that has shown to be therapeutically efficacious. Linezolid is a new Oxazolidinone medicine. It kills a broad spectrum of bacteria, including Staphylococcus aureus.

Objectives: To reduce non-target organ adverse effects associated with frequent and chronic Linezolid usage, we developed biodegradable, lung-targeted microspheres with sustained release profile.

Methods: In this work, a Buchi B-90 nanospray drier was used to prepare a Linezolid-loaded carbopol microsphere (CLSMO)-based formulation. The spray-drying process was optimized using a face-centered central composite design (CCD).

Results: The average particle size was 7.516 µm, and the surface of the microspheres was shriveled, according to scanning electron microscope imaging. Drug content and yield were determined to be 73% 3.1% and 72% ± 2.4%., respectively, and drug release (99.1%) peaked for up to 12 hours in vitro. FTIR spectral analysis results suggest that there are no significant physical and chemical interactions between the functional groups of Linezolid and carbopol 934P polymer which ultimately form a stable blend. Linezolid, Carbopol, and CLSMO all had XRD patterns that showed the linezolid would be molecularly dispersed in the polymer. The DSC findings revealed the drug's amorphous nature, which explains the absence of characteristic peaks, indicating a lack of well-defined crystalline structure.

Conclusion: The optimized formulation shows significant potential for use as a drug-delivery system in in-vivo applications, particularly in targeted drug delivery to the lungs.