Comparative oral bioavailability advantage from curcumin formulations

The aim of the present study was to study the oral bioavailability of seven different formulations of curcumin (CRM). CRM formulations viz. aqueous suspension, micronized suspension, nanosuspension, amorphous solid dispersion, hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex, combination with piperine, and spray-dried CRM-milk composite were compared for oral bioavailability in male Sprague-Dawley rats at a CRM dose of 250 mg/kg body weight using a validated high-performance liquid chromatography method. Aqueous suspension provided a C _max and AUC _{(0 - t)} of 28. 9 ng/ml and 26. 9 ng h/ml, respectively. In comparison, statistically significant increase in the oral bioavailability was obtained with the nanosuspension, HP-β-CD inclusion complex, and amorphous solid dispersion with 251%, 567%, and 446% increase in terms of AUC _{(0 - t)} and 405%, 415%, and 270% in terms of C _max. However, no significant increase in AUC _{(0 - t)} and C _max was observed with piperine and micronized suspension. The milk composite reduced the oral bioavailability of CRM (10% and 37% in terms of AUC _{(0 - t)} and C _max). A statistically significant increase in the T _max was observed with piperine and in HP-β-CD complex, while the T _max was reduced for nanosuspension. The results provide interesting insights into the role of solubility enhancement and metabolism inhibition, for improving the oral bioavailability of CRM.