Comparative pharmacokinetic analysis of curcumin and curcumin O-glucuronide through curcumin nano-gel-based delivery system using liquid chromatogram tandem mass spectrometry

Background: Curcumin exhibits limited oral bioavailability owing to its poor solubility and rapid metabolism. Objectives: To develop a novel curcumin nano-gel (CNG) and evaluate its pharmacokinetics following oral and rectal administration. Methods: A sensitive LC MS/MS method was established for the simultaneous quantification of curcumin and its major metabolite curcumin O glucuronide (COG) in plasma. The pharmacokinetics of CNG were compared with those of curcumin suspension (CS) to evaluate the improvement in oral and rectal absorption. CNG and curcumin suspension (CS) were administered orally (1000?mg/kg) and rectally (200?mg/kg) to mice or rats. Plasma samples were collected, and pharmacokinetic parameters were analyzed using WinNonlin. Results: CNG formed well dispersed nanoparticles in water. Oral administration of CNG significantly enhanced curcumin absorption, yielding a 66.7 fold higher Cmax for curcumin and an 84.8 fold higher Cmax for COG compared with CS. The AUC of curcumin and COG increased by 9.2 fold and 24.4 fold, respectively. Rectal administration of CNG resulted in a 5.5 fold higher Cmax and a 3.5 fold higher AUC of curcumin relative to oral CS. Conclusion: CNG markedly improves the bioavailability of curcumin via both oral and rectal routes, demonstrating its potential as an effective delivery system for enhancing curcumin therapeutic application.