Formulation optimization of solid self-microemulsifying pellets for enhanced oral bioavailability of curcumin

Abstract

Solidification of self-microemulsifying drug delivery systems (SMEDDS) is one of the major trends to promote the transformation of self-microemulsion technology into industrialization. Here, a preliminary curcumin SMEDDS formulation was constructed to improve the druggability of curcumin, through the determination of equilibrium solubility determination, self-emulsifying grading assessment, and pseudo-ternary phase diagrams drafting. Furthermore, the optimal curcumin SMEDDS formulation consisted of 10% Ethyl oleate, 57.82% Cremophor RH 40, and 32.18% Transcutol P was obtained by the simplex lattice design. Besides, curcumin solid self-microemulsifying drug delivery system (S-SMEDDS) was developed by the extrusion and spheronization process to achieve the solidification of SMEDDS. The formulation of curcumin S-SMEDDS pellets was screened by the single factor experiment and the process parameters were investigated using the orthogonal optimization method. Subsequently, curcumin S-SMEDDS pellets were evaluated by apparent morphology characterization, redispersibility study, drug release behavior, and pharmacokinetic evaluation. Results from the pharmacokinetic study in rabbits showed that the AUC_0–τ of the curcumin S-SMEDDS pellets and curcumin suspension were 5.91 ± 0.28 µg/mL·h and 2.05 ± 0.04 µg/mL·h, while the relative bioavailability was 289.30%. These studies demonstrated that S-SMEDDS pellets can be a promising strategy for curcumin industrialized outputs.

Keywords:

• Curcumin
• self-microemulsifying
• pellets
• bioavailability
• formulation optimization

Disclosure statement

No potential conflict of interest was reported by the author(s)

Additional information

Funding

This work was supported by the Administration of Traditional Chinese Medicine of Zhejiang Province [Program No. 2017ZA075].