A Novel Approach for the Development of a Nanostructured Lipid Carrier Formulation by Hot-Melt Extrusion Technology

The main aim of this study was to investigate the feasibility of preparing nanostructured lipid carrier (NLC) utilizing hot-melt extrusion (HME) coupled with probe sonication. The process parameters for HME and sonication were optimized and a modified screw configuration was used for extrusion. Lidocaine-loaded NLCs were successfully prepared by the proposed method with particle size <50 nm and polydispersity index <0.3. Transmission electron microscopy revealed the spherical nature of the particles. The second objective was to develop NLCs for topical controlled delivery of drug for pain management in cutaneous wounds. The entrapment efficiency of drug-loaded NLCs was found to be 73.9%. The formulation was subjected to permeation studies across porcine epidermis using a Franz diffusion setup. The drug permeation from the NLC-loaded carbopol gel was found to be sustained as compared to permeation from the gel without lipids. Furthermore, mechanistic studies were performed using tape stripped and intact skin models to ascertain the fact that the predominant rate controlling process was release of drug from the NLCs. In summary, the conventional HME process can be modified for continuous manufacturing of NLCs, which are otherwise prepared by batch processing involving multiple and complicated processing steps.