Design and Characterization of Glyceryl Monostearate Solid Lipid Nanoparticles Prepared by High Shear Homogenization

Aims: The aim of this study was to explore the practicability of preparation of solid lipid nanoparticles of Glyceryl monostearate containing Dibenzoyl peroxide, Erythromycin base, and Triamcinolone acetonide as model drugs. The physicochemical properties of the prepared formulae like particle size, drug entrapment efficiency, drug loading capacity, yield content and in-vitro drug release behavior were also measured.
Methodology: Solid lipid nanoparticles loaded with three model lipophilic drugs were prepared by high shear hot homogenization method. The model drugs used are Dibenzoyl peroxide, Erythromycin base, and Triamcinolone acetonide. Glyceryl monostearate was used as lipid core; Tween 20 and Tween 80 were employed as surfactants and lecithin as co-surfactant. Many formulation parameters were controlled to obtain high quality nanoparticles. The prepared solid lipid nanoparticles were evaluated by different standard physical and imaging methods. The efficiency of drug release form prepared formulae was studied using in vitro technique with utilize of dialysis bag technique. The stability of prepared formulae was studied by thermal procedures and infrared spectroscopy.
Results: The mean particle diameter measured by laser diffraction technique was (194.6±5.03 to 406.6±15.2 nm) for Dibenzoyl peroxide loaded solid lipid nanoparticles, (220±6.2 to 328.34±2.5) nm for Erythromycin loaded solid lipid nanoparticles and (227.3±2.5 to 480.6±24) nm for Triamcinolone acetonide loaded solid lipid nanoparticles. The entrapment efficiency and drug loading capacity, determined with ultraviolet spectroscopy, were 80.5±9.45% and 0.805±0.093%, for Dibenzoyl peroxide, 96±11.5 and 0.96±0.012 for Triamcinolone acetonide and 94.6±14.9 and 0.946±0.012 for Erythromycin base respectively. It was found that model drugs showed significant faster release patterns when compared with commercially available formulations and pure drugs (pË‚0.05). Thermal analysis of prepared solid lipid nanoparticles gave indication of solubilization of drugs within lipid matrix. Fourier Transformation Infrared Spectroscopy (FTIR) showed the absence of new bands for loaded solid lipid nanoparticles indicating no interaction between drugs and lipid matrix and being only dissolved in it. Electron microscope of scanning and transmission techniques indicated sphere form of prepared solid lipid nanoparticles with smooth surface with size below 100 nm.
Conclusions: Solid lipid nanoparticles with small particle size have high encapsulation efficiency, and relatively high loading capacity for Dibenzoyl peroxide, Erythromycin base, and Triamcinolone acetonide as model drugs can be obtained by this method.