Fabrication of nanoemulsion system containing chloramphenicol and palm kernel oil esters for parenteral treatment of meningitis

Meningitis is a disease caused by a bacterial infection in the brain. Streptococcus pneumonia is the most common causative agent for meningitis disease. Chloramphenicol used to be a drug used for the treatment of meningitis. Current medication in treating meningitis is using the family of cephalosporin drugs. However, due to the drug-resistant problem, this family of a drug is no longer efficient towards the meningitis bacteria. Thus, the use of chloramphenicol has caught back the attention in treating meningitis disease. Chloramphenicol is claimed to be toxic towards human cells since the higher dosage is needed per injection for every treatment. This is corresponding to the poor delivery method of this hydrophobic drug. Nanoemulsion is believed to be the best option in transporting chloramphenicol to the brain by the intravenous route. A good combination of oil mixed with a surfactant mixture led to the formation of formulation with small particle sizes with low PDI values. Optimization of nanoemulsion's composition using Response Surface Methodology (RSM) suggested that the best amount of oil, lecithin, and glycerol were 4%, 2.5%, and 2.25%, respectively. The optimized formulation was then modified due to the instability and insufficient osmolality value of the formulation. The physicochemical characteristics (particle size, PDI, zeta potential, osmolality, viscosity, and pH) of the formulation successfully fulfilled the requirement for parenteral application. Toxicity analysis showed that chloramphenicol encapsulated nanoemulsion system was much safer compared to the standard chloramphenicol. Storage of the chloramphenicol-loaded nanoemulsion at 4°C showed good stability for 3 months with no significant changes on the particle size.