Nasotransmucosal Delivery of Curcumin-Loaded Mucoadhesive Microemulsions for Treating Inflammation-Related CNS Disorders

Objectives: This investigation was aimed at designing an effective mucoadhesive microemulsion system to accomplish higher brain uptake of curcumin through intranasal route.

Materials and methods: Mucoadhesive microemulsion of curcumin (MMEC) was developed using screened oil, surfactant, and co-surfactant by Box-Behnken design and was evaluated for mucoadhesion, stability, and naso-ciliotoxicity study. Comparative brain uptake of curcumin after nasal administration of MMEC and polycarbophil curcumin gel and intravenous administration of plain curcumin solution was studied by performing bio-distribution study in Swiss albino rats.

Results: The results showed that all formulation variables i.e., the amount of capmul MCM (X1), S_mix (accenon CC: transcutol P) (X2) and percentage of aqueous. Polycarbophil (X3) had a significant effect (p<0.05) on the responses. The developed MMEC was stable and non-ciliotoxic with 66.74 ± 3.46 nm and 98.58% ± 1.21 as average globule size and drug content, respectively. Polydispersibility index (0.133 ± 0.17) data and transmission electron microscopy study depicted the narrow size distribution of MMEC. Furthermore, following a comparative investigation of the brain uptake of curcumin among MMEC, plain drug gel and intravenous administration at 2.86 mg/kg, more brain uptake of curcumin was demonstrated for MMEC over intravenous application. Moreover, curcumin uptake in olfactory bulb after nasal administration of MMEC (31.11 ± 1.6) was than 9.44 times higher than intravenous injection of curcumin solution (3.25 ± 1.01). Area under curve represents the ratio of 2.86 mg/kg in brain tissue to plasma acquired afterward(s) the intranasal injection of MMEC (and it) was essentially greater than after the intravenous administration of curcumin solution.

Conclusion: Findings of the investigation revealed that optimal MMEC and intranasal route may be considered to be promising and an alternative approach for brain targeting of curcumin.