Abstract
Atorvastatin is an extensively used lipid lowering agent. But the vital issue associated with it is low oral bioavailability (12%) owing to poor aqueous solubility. To overcome this tribulation, binary solid lipid nano suspension of Atorvastatin (ATO) was formulated by solvent diffusion method. The combination of stearic acid and oleic acid was utilized as a lipid carrier with Tween-80 (surfactant) along with Polyvinylpyrrolidone (co-surfactant). Optimized nano formulation was prepared by changing the formulation variables. Optimized nano suspension (ATO-4) represented particle size 228.3 +/- 2.1 nm and polydispersity index (PDI) 0.225 +/- 0.02 with zeta potential (ZP) -33.610.02 mV. Encapsulation efficiency along with drug loading capacity was 88.3 +/- 2.5% and 4.9 +/- 0.14% respectively. Scanning electron microscopic (SEM) analysis exposed spherical shaped amorphous particles. Differential scanning calorimetry (DSC) as well as X-ray powder diffraction (P-XRD) established reduction in drug's crystalline state. Fourier transform infrared (FTIR) spectroscopy exposed no interaction amongst the drug and formulation contents. In-vitro studies revealed sustained pattern of drug release. Stability studies confirmed refrigerated temperature as most suitable for storage of binary solid lipid nano suspension. Plasma concentration versus time curve ascertained 2.78-fold increase in oral bioavailability of ATO nano suspension compared to the marketed product (Lipitor (R)). Findings proposed desired improvement in oral bioavailability of ATO nano suspension with sustained drug release profile. Thus, binary solid lipid nano suspension could be utilized as an advanced drug delivery system for oral deliverance of hydrophobic drugs.