Modification of palm kernel oil esters nanoemulsions with hydrocolloid gum for enhanced topical delivery of ibuprofen

Norazlinaliza Salim,¹ Mahiran Basri,^1,2 Mohd BA Rahman,¹ Dzulkefly K Abdullah,¹ Hamidon Basri<sup>3

1</sup>Department of Chemistry, Faculty of Science, ²Laboratory of Biomolecular Medicine, Institute of Bioscience, ³Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Selangor, Malaysia

Introduction: During recent years, there has been growing interest in the use of nanoemulsion as a drug-carrier system for topical delivery. A nanoemulsion is a transparent mixture of oil, surfactant and water with a very low viscosity, usually the product of its high water content. The present study investigated the modification of nanoemulsions with different hydrocolloid gums, to enhanced drug delivery of ibuprofen. The in vitro characterization of the initial and modified nanoemulsions was also studied.
Methods: A palm kernel oil esters nanoemulsion was modified with different hydrocolloid gums for the topical delivery of ibuprofen. Three different hydrocolloids (gellan gum, xanthan gum, and carrageenan) were selected for use. Ternary phase diagrams were constructed using palm kernel oil esters as the oil, Tween 80 as the surfactant, and water. Nanoemulsions were prepared by phase inversion composition, and were gradually mixed with the freshly prepared hydrocolloids. The initial nanoemulsion and modified nanoemulsions were characterized. The abilities of the nanoemulsions to deliver ibuprofen were assessed in vitro, using a Franz diffusion cell fitted with rat skin.
Results: No significant changes were observed in droplet size (~16–20 nm) but a significant difference in polydispersity indexes were observed before and after the modification of nanoemulsions using gellan gum, carrageenan, and xanthan gum. The zeta potentials of the initial nanoemulsions (–11.0 mV) increased to –19.6 mV, –13.9 mV, and –41.9 mV, respectively. The abilities of both the initial nanoemulsion (T802) and the modified nanoemulsion to deliver ibuprofen through the skin were evaluated in vitro, using Franz diffusion cells fitted with rat skin. The in vitro permeation data showed that the modified nanoemulsion (Kp value of 55.4 × 10^-3 cm • h^-1) increased the permeability of ibuprofen 4.40 times over T802 (Kp value of 12.6 × 10^-3 cm • h^-1) (P < 0.05).
Conclusion: The modified nanoemulsion may be a promising vehicle to enhance the permeation of ibuprofen for topical delivery.

Keywords: ibuprofen, in vitro study, palm kernel oil esters, topical delivery