Raloxifene HCl (RLX) is used in prevention and treatment of post-menopausal osteoporosis in women. It has poor oral
bioavailability (less than 2%) and shows high inter-patient variability. The present study aimed at developing oral poly-
[epsilon]-caprolactone (PCL) nanocapsules of RLX using modified multiple emulsion technique (w/o/w) to improve its oral
bioavailability. The Rotatable Central Composite Design (RCCD) is used in the present study to understand the effects of process
variables on two responses: particle size and entrapment efficiency (EE) of the nanocapsules. Three critical factors identified
in the study were amount of polymer, amount of surfactant (Lutrol F-127) and ultrasonication time (at 30 W output). Particle
size and zeta potential were measured by Malvern Zetasizer. Loading efficiency and EE were determined for the developed
nanocapsules. In-vitro drug release profiling was done in pH 7.4 phosphate buffered saline. Further characterization of the
polymeric nanocapsules was done by FT-IR and DSC. Response surface methodology was used to determine the influence of
multiple factors on particle size and EE of formulations. The particle size ranged from 134 ? 4 nm to 230 ? 3 nm for different
formulations. All the formulations carried negative surface charge. The EE values ranged from 43 ? 5% to 85 ? 3%. The experiments
carried out at the center points indicated the reproducibility of the method with RSD less than 4% for both particle size and EE.
From the analysis of data, it was shown that amount of PCL had linear effect on particle size of the nanocapsule, while EE was
inversely affected by amount of surfactant and ultrasonication time. Drug was found to be compatible with the excipients used.
In-vitro drug release showed biphasic release pattern, characterized by an initial burst release of RLX followed by slower and more
continuous release up to 72 h. The optimized formulation provided particles with required particle size (below 250 nm) and high
Punna Rao Ravi has completed his Ph.D. from Birla Institute of Technology and Science, Pilani, Rajasthan. He is currently working as Assistant
Professor in Pharmacy Department, Birla Institute of Technology and Science-Pilani Hyderabad Campus. He has published more than 12 papers in
reputed international journals.
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