| Popis: |
The objective of the present work was to optimize ritonavir (RTV) loaded nanostructured lipid carriers (NLCs) to improve bioavailability using quality by design (QbD) based technique. Risk assessment was studied using ‘cause and effect’ diagram followed by failure mode effect analysis (FMEA) to identify the effective high-risk variables for the formulation development. Quality target product profile (QTPP) and critical quality attributes (CQAs) were initially assigned for the proposed product. Central composite rotatable design (CCRD) was used to identify the individual and combined interactions of formulation variables. RTV loaded NLC (RTV-NLC) was prepared using emulsification-ultrasonication method. The effect of formulation variables like ultrasound amplitude, lipid concentration, surfactant concentration on their responses like particle size, polydispersity index (PDI), and entrapment efficiency (EE) were studied by CCRD. The optimized formulation was subjected to lyophilization to obtain dry NLCs for solid-state analysis. DSC and PXRD investigations showed RTV was molecularly dispersed in lipid matrix indicating amorphous form present in the formulation. FESEM and AFM depicted the spherical and uniform particles. The enhanced solubility and dissolution may be attributed due to the reduced particle size. The optimized NLCs showed good physical stability during storage for six months. RTV-NLC was further subjected to in vitro studies and found a successful sustained release rate of 92.37±1.03 %. The parallel artificial membrane permeability assay (PAMPA) and everted gut sac model have demonstrated the permeation enhancement of RTV. In vivo study observed the enhanced bioavailability with 2.86 fold suggesting optimized NLC successfully overcome the issue of solubility. |
