Ocular Formulation Based on Palmitoylethanolamide-Loaded Nanostructured Lipid Carriers: Technological and Pharmacological Profile

Abstract

The present work was aimed for the preparation of a stable nanostructured lipid carrier (NLC) system for the delivery of N-palmitoylethanolamide (PEA) to the back of the eye. PEA is an interesting natural compound showing anti-inflammatory and neuroprotective activities. The limits of PEA (poor solubility and high instability) justify its nanoencapsulation into drug delivery systems. Two different well-known techniques were compared to formulate NLC: the high shear homogenization technique (HSH) and the method based on a combination of HSH technique and ultrasonication (HSH/US). Nanoparticles were evaluated in relation to mean size, homogeneity, surface charge, and physical stability by Turbiscan technology. Retinal distribution of PEA was carried out in a rat eye after single instillation of PEA-NLC ophthalmic formulation. The novel formulation delivered remarkable levels of PEA to the retina. Lastly, topical administration of PEA-NLC ophthalmic formulation was able to significantly inhibits retinal tumor necrosis factor-α (TNF-α) levels in streptozotocin-induced diabetic rats. The present findings suggest that the novel ophthalmic formulation may be useful for the treatment of retinal diseases such as diabetic retinopathy. Clinical studies are in progress to evaluate this possibility.

Lipid-Based Nanocarriers as Topical Drug Delivery Systems for Intraocular Diseases

“…The increasing efficiency of lipid-based nanocarriers over the last years has made them a target for constant and thorough research. In fact, these formulations have been already used in both preclinical and clinical practice demonstrating favorable outcomes treating ocular diseases [ 10 , 11 , 16 , 51 , 87 , 91 , 98 , 103 , 126 , 131 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 , 157 , 158 , 159 , 160 , 161 , 162 , 163 , 164 , 165 , 166 , 167 , 168 , 169 ]. With all these promising results and taking advantage of the new technologies, researchers, pharmacists, and clinical professionals must continue this line of investigation and encourage the use of these new formulations in the near future in clinical medical practice.…”

Curcumin Containing PEGylated Solid Lipid Nanoparticles for Systemic Administration: A Preliminary Study

“…First, 20 mL of each sample were placed in a cylindrical glass cell and positioned in the Turbiscan ® at 25 °C for 30 days. Turbiscan ® AGS has been previously reported as a reliable technology to evaluate the occurrence of instability phenomena related to particle aggregation and/or migration [ 49 , 50 , 51 , 52 , 53 , 54 ]. In our experiments, the stability of the samples was evaluated based on the variation of transmission (ΔT), which is shown in ordinate, while the height of the cell is reported in abscissa.…”

Nanostructured Lipid Carriers for Delivery of Chemotherapeutics: A Review

“…This technique is simple and suitable for large scale production. It does not require organic solvents and results in highly stable NPs [28,33,34,38]. However, using hot HPH for the preparation of drug-loaded NLCs is limited by the thermolability of the drug as well as the low entrapment efficiency and reduced drug loading capacity that may occur due to permeation of the drug molecules into the hydrophilic phase during the crystallization of the lipid phase [14,26].…”