Formulation of transdermal nanoemulsion gel drug delivery system of lovastatin and its in vivo characterization in glucocorticoid induced osteoporosis rat model

Lovastatin possess bone formation capabilities but due to first pass effect could not provide significant results. Thus the aim of present investigation was to formulate a transdermal nanoemulsion (NE) gel drug delivery system to overcome its drawbacks and evaluate its potential on glucocorticoid induced osteoporosis (GIOP) in rats. NEs of size range 11-123 nm were prepared with labrafac PG, tween 80 and transcutol using pseudo-ternary phase diagrams. NEs were formulated into gel using carbopol 940 and evaluated for ex vivo permeation testing using rat abdominal skin. Finally, lovastatin NE gel preparations were tested against normal and GIOP induced rats. Femurs of rats were collected and tested for microarchitecture and biomechanical strength testing. Lovastatin NE gel preparations (LNG5 and LNG10) showed significant improvements in the microarchitecture of trabeculae near the growing plates and the strength of femurs as compared to the GIOP group. Bone resorption biomarkers (CTx and TrAcP) were reduced significantly while bone formation biomarkers (b-ALP, OC and PINP) were significantly improved in the LNG5 (p < 0.05) and LNG10 (p < 0.05) treated groups when compared to GIOP. The results suggested that LNG formulations showed promising results for improving bone microstructure and strength after osteoporosis induction.