# Preparation and In Vitro Characterization of Triamcinolone Acetonide-Loaded Lipid Liquid Crystal Nanocarriers for Ocular Delivery

## TL;DR

This study developed and tested lipid-based nanocarriers for delivering triamcinolone acetonide to the eye, showing potential for sustained drug release.

## Contribution

The novel use of lipid liquid crystals for ocular delivery of TA with sustained release properties is introduced.

## Key findings

- Formulations showed acceptable particle size, PDI, and zeta potential for ocular delivery.
- Drug release reached 100% within 48 hours, except for the HPβCD-containing formulation.
- Hexosomes and cubosomes were observed, contributing to uniform drug release.

## Abstract

This study aimed to develop sustained-release triamcinolone acetonide (TA) formulations using lipid liquid crystals (LLCs) for ocular drug delivery and to characterize the designed formulations.

Eighteen dispersed LLC formulations were prepared through a top-down approach, incorporating varying concentrations of TA and different proportions of glyceryl monooleate, deionized water, and pluronic F127. An additional formulation comprising TA: hydroxypropyl beta-cyclodextrin (HPβCD) complex was also developed to investigate the influence of HPβCD on the properties of the formulations. The formulations were evaluated for their rheological properties in room temperature using a rheometer, syringeability by passing them through a 27G needle, size measurements via dynamic light scattering (DLS), and morphology through polarized light microscopy (PLM). Furthermore, the prepared formulations were injected into a dialysis tube and placed in a phosphate buffer at pH 7.4 and 37 °C for in vitro release evaluation. Samples were taken at predetermined intervals and stored in a refrigerator until HPLC analysis. The percentage of Encapsulation efficacy and drug loading were evaluated using an indirect method. A reversed-phase HPLC method was employed to quantify the drug concentrations in the samples.

All selected formulations demonstrated acceptable parameters, including particle size (less than 200 nm), polydispersity index (PDI) ranging from 0.202 to 0.355, and zeta potential values between -14.3 and -32.8 mV. Additionally, the formulations showed good syringeability and achieved 100% drug release within 48 hours (except for the formulation containing HPβCD). PLM analysis revealed the presence of hexosomes and cubosomes, indicating that an increase in hexosomes contributed to a more uniform drug release from the formulations.

Overall, the study findings suggest that liquid crystalline carriers can be a promising formulation for sustained ocular drug delivery of TA.