Aim
Intend of the present exertion is to prepare β-cyclodextrin (β-CD) based polymeric nanosuspension (PNS) of Efavirenz (EFV) with enhanced aqueous solubility and dissolution rate as compared to pure drug.

Background
EFV is a low aqueous soluble molecule because of which there is drug absorption problem. To overcome this problem polymeric nanosuspension were prepared using precipitation method which produced successful results.

Materials and methods
Four formulations (β-CDPNS1, β-CDPNS2, β-CDPNS3 and β-CDPNS4) with varying drug-polymer ratios were prepared by precipitating drug-polymer physical mixtures dissolved in organic phase in an aqueous phase. Solid state characterization of β-CDPNS's were conducted using X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy-universal attenuated total reflectance (FTIR-UATR), and scanning electron microscopy (SEM) to examine physical properties and to study the compatibility of EFV with pharmaceutical excipients. Dynamic light scattering (DLS) studies was performed for nanoparticles evaluation.

Results
The mean diameter of the nanoparticles ranged between 143.8 and 284.4 nm and polydispersity index (Pdi) values for all the nanosuspensions were small (<0.30) indicating the uniform mono-disperse with zeta potential (mV) values ranging from −38.3 to −27.5 mV. SEM images revealed the layered morphology for all β-CDPNS. The solubility and dissolution profile of EFV nanosuspensions markedly increased when compared to the original drug. Kinetics of drug release mechanism was studied using eight mathematical models and found that the release profiles of β-CDPNS were best described by Weibull model with dissolution efficiency (DE) >60% in each formulation.

Conclusion
Successful preparation and characterization of Efavirenz nanosuspension by solvent injection method has been accomplished in this study.