Polymeric nanoparticles containing babassu oil: A proposed drug delivery system for controlled release of hydrophilic compounds

Different drug delivery systems are prepared on the nanoscale to improve performance in drug formulations, such as nanoparticles or nanoemulsions. Polymeric nanoparticles have been used to encapsulate drugs for several applications because of some characteristics of these carriers to control drug delivery, transport molecules to a specific tissue, protect the drugs, and increase drug bioavailability. When using nanocapsules, an essential parameter for encapsulating different hydrophilic or lipophilic molecules is the characteristics of the core. Babassu oil (BBS) is a natural product from Brazil, composed majoritary of short-chain saturated fatty acids. BBS has an elevated hydrophilic-lipophilic balance (HLB), which may promote interaction of the oil with hydrophilic drugs. In this study, we developed and characterized particles containing babassu oil, solely or combined with sorbitan monostearate (Span® 60) or medium chain triglycerides (MCT) in the core to test different HLB and evaluated the encapsulation of a model hydrophilic molecule. Different techniques were used to characterize all formulations in terms of size and distribution, and in vitro drug release by dialysis technique was performed. The BBS was also characterized and presented 46,05 ± 1,11% and 15,38 ± 0,06% of lauric and myristic acid, respectively; saponification index of 248.87 ± 0.64 mg of KOH per gram of BBS, and no oxidation of the oil was indicated by means of peroxide index. Evaporation of solvent carried in the room or reduced pressure influenced the particles' size; nevertheless, all had a z-average smaller than 220 nm. Nanoparticles with a ratio among aqueous phase and organic phase of 2.8 were considered adequate to encapsulate diclofenac sodium. The particles size/zeta potential were 189.83 ± 7.86 nm / − 10.39 ± 2.52 mV, 156.80 ± 4.77 nm / − 9.27 ± 4.61 mV, and 168.87 ± 5.22 nm / − 12.98 ± 4.66 mV to nanoparticles prepared with BBS + MCT, BBS, and BBS + Span® 60, respectively. All formulations exhibited an amount of drug content close to the theoretical amount (1.0 mg mL⁻¹), and no difference was observed in the release profile among the three nanoparticles. Formulation containing only babassu oil in the core displayed 66.78 ± 15.62% of encapsulation efficiency to diclofenac sodium, the highest value among all formulations tested. Results demonstrate that the innovative nanoparticles containing BBS promote the encapsulation of a model hydrophilic molecule, and other components can be evaluated to change the core’s hydrophilicity and encapsulation of molecules.