Mucoadhesive nanostructured lipid carriers (NLCs) as potential carriers for improving oral delivery of curcumin

Abstract

Purpose: To examine effects of polymer types on the mucoadhesive properties of polymer-coated nanostructured lipid carriers (NLCs).

Experiment: Curcumin-loaded NLCs were prepared using a warm microemulsion technique followed by coating particle surface with mucoadhesive polymers: polyethylene glycol400 (PEG400), polyvinyl alcohol (PVA), and chitosan (CS). The physicochemical properties and entrapment efficacy were examined. In vitro mucoadhesive studies were assessed by wash-off test. In addition, the stability of mucoadhesive NLCs in gastrointestinal fluids and the pattern of drug release were also investigated.

Findings: The obtained nanoparticles showed spherical shape with size ranging between 200 nm and 500 nm and zeta potential between −37 and −9 mV depending on the type of polymer coating. Up to 80% drug entrapment efficacy was observed. In vitro mucoadhesive studies revealed that PEG-NLCs and PVA-NLCs were adhered strongly to freshly porcine intestinal mucosa, more than 2-fold mucoadhesive compared to CS-NLCs and uncoated-NLCs. The particle size of all polymer-coated NLCs could be maintained in both simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) suggesting good physical stability in physiological fluid. In contrast, uncoated-NLCs showed particle aggregation in SGF. In vitro dissolution studies revealed a fast release characteristic.

Keywords:

• Nanostructured lipid carriers
• mucoadhesion
• curcumin
• polyvinyl alcohol
• polyethylene glycol 400

Acknowledgements

We acknowledge the Faculty of Pharmaceutical Sciences, Naresuan University for providing necessary facilities. We also thank Dr. Charles Norman Scholfield for valuable suggestions on results and discussions.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

This study was financially supported by Naresuan University, 10.13039/501100004944, [R2558B030] and the Center of Excellence for Innovation in Chemistry (PERCH-CIC), Commission on Higher Education, Ministry of Education, Thailand.