Development and In Vitro Characterization of Solid Lipid Nanoparticles(SLN) Containing Methotrexate And Doxycycline

Abstract

Solid lipid nanoparticles (SLN) containing Disease Modifying Antirheumatic drugs (DMARDs) Methotrexate (MTX) and Doxycycline (DOX) was developed using a triglyceride (tristearin) and a polaxamer (pluronic F68). Hot homogenization of melted lipid and aqueous phase at temperature above the melting point of lipid had produced SLN dispersion. Optimization of process and formulation variables have yielded SLN having an entrapment efficiency of 65.07%±1.23% and 79.56%±0.92% for MTX and DOX respectively. Particle size and zeta potential measured using Malvern Zetasizer showed 157.2nm and -9.6mv respectively for the optimized SLN formulation. The compatibility between the drug and the formulation excipients was tested by Fourier Transform Infrared Spectroscopy (FTIR) and found to be compatible. Powder X-ray diffraction (PXRD) study revealed that the drugs and lipid were dispersed in crystalline state in SLN. The in vitro drug release studies performed in phosphate buffer of pH 7.4 using dialysis bag showed a sustained release of both the drugs (andgt;75%±1.4%) up to a period of two days. From the in vitro results, it can be concluded that SLN was found to be a suitable nano carrier for the incorporation of DMARDS: MTX and DOX without any significant interaction. The developed system produced sustained release of both the drugs (based on their concentration) for longer duration and thus suitable for the chronic inflammatory conditions of RA.