Comparison and process optimisation of PLGA, chitosan and silica nanoparticles for potential oral vaccine delivery

Aims: The study compared performance of nanoparticles from synthetic organic, natural organic and inorganic materials as vaccine delivery platforms. Methods: Various formulation (concentration, polymer/silica: surfactant ratio, solvent) and process parameters (homogenization speed and time, ultra-sonication) affecting functional performance characteristics of poly(lactic-co-glycolic acid) (PLGA), chitosan and silica based nanoparticles containing bovine serum albumin were investigated. Nanoparticles were characterised using dynamic light scattering, X-ray diffraction, scanning/transmission electron microscopy, Fourier transform infrared spectroscopy and in vitro protein release. Results: Critical formulation parameters were surfactant concentration (PLGA, silica) and polymer concentration (chitosan). Optimised nanoparticles were spherical in shape with narrow size distribution and size ranges of 100-300 nm (blank) and 150-400 nm (protein loaded). Protein encapsulation efficiency was 26-75% and released within 48 hours in a sustained manner. Conclusion: Critical formulation and process parameters affected size of PLGA, chitosan and silica nanoparticles and protein encapsulation, whilst silica produced the smallest and most stable nanoparticles

Curcuminoids-loaded lipid nanoparticles: Novel approach towards malaria treatment

In the present work, curcuminoids-loaded lipid nanoparticles for parenteral administration were successfully prepared by a nanoemulsion technique employing high-speed homogenizer and ultrasonic probe. For the production of nanoparticles, trimyristin, tristerin and glyceryl monostearate were selected as solid lipids and medium chain triglyceride (MCT) as liquid lipid. Scanning electron microscopy (SEM) revealed the spherical nature of the particles with sizes ranging between 120 and 250 nm measured by photon correlation spectroscopy (PCS). The zeta potential of the particles ranged between -28 and -45 mV depending on the nature of the lipid matrix produced, which also influenced the entrapment efficiency (EE) and drug loading capacity (LC) found to be in the range of 80-94% and 1.62-3.27%, respectively. The LC increased reciprocally on increasing the amount of MCT as confirmed by differential scanning calorimetry (DSC). DSC analyses revealed that increasing imperfections within the lipid matrix allowed for increasing encapsulation parameters. Nanoparticles were further sterilized by filtration process which was found to be superior over autoclaving in preventing thermal degradation of thermo-sensitive curcuminoids. The in vivo pharmacodynamic activity revealed 2-fold increase in antimalarial activity of curcuminoids entrapped in lipid nanoparticles when compared to free curcuminoids at the tested dosage level.