Physicochemical attributes and dissolution testing of ophthalmic ointments

Abstract

The investigation of semisolid ophthalmic ointments is challenging due to their complex physicochemical properties and the unique anatomy of the human eye. Using Lotemax as a model ophthalmic ointment, three different manufacturing processes and two excipient sources (Fisher (OWP) and Fougera (NWP)) were used to prepare loteprednol etabonate ointments that were qualitatively and quantitatively the same across the manufactured formulations. Physicochemical properties including drug content and uniformity, particle size and distribution, as well as rheological parameters (onset point, crossover modulus, storage modulus and Power law consistency index) were investigated. In addition, USP apparatus 2 with enhancer cells was utilized to study the in vitro drug release characteristics of the ophthalmic ointments. Both manufacturing processes and excipient sources had a significant influence on the physicochemical attributes and the in vitro drug release profiles of the prepared ointments. Ointments prepared via the hot melt processes exhibited higher rheological parameters and lower drug release rates compared to ointments prepared without hot melting. Ointments prepared with OWP demonstrated higher rheological parameters and lower in vitro drug release rates compared to ointments prepared with NWP. A strong correlation between the rheological parameters and in vitro drug release rate was shown using logarithmic linear regression. This correlation may be useful in predicting in vitro drug release from measured physicochemical properties, and identifying the critical quality attributes during the development of ointment formulations.

Influence of Concentration on Release and Permeation Process of Model Peptide Substance-Corticotropin-From Semisolid Formulations

“…The high-quality design of cells or adapters for sampling (Enhancer cells and semi-solid adapters) ensure good reproducibility of the sample placement. In addition, pharmacopoeial methods were standardised [35,36].…”

Hydrogel Biomaterials for Application in Ocular Drug Delivery

“…There are many formulations currently on the market which are designed to treat ophthalmic conditions. These range from anterior segment conditions such glaucoma, bacterial conjunctivitis, and post-operative inflammation to posterior segment conditions such as neovascular age-related macular degeneration, uveitis, and macular edema (Sultana et al, 2006b;Bao et al, 2017;Kaji et al, 2018). Each of the drug delivery systems discussed below has distinctive disadvantages when it comes to the effective delivery of drugs to the eye.…”

“…Poor content uniformity, Known to cause blurred vision when applied, inaccurate dosing, eyelid matting. Li J. et al, 2013;Bao et al, 2017;Shen et al, 2018 Contact lenses Post-operative barrier for protection of cornea, pain relief, protection of cornea following injury.…”

In Situ Gelling Ophthalmic Drug Delivery System for the Optimization of Diagnostic and Preoperative Mydriasis: In Vitro Drug Release, Cytotoxicity and Mydriasis Pharmacodynamics

“…Moreover, these phenomena exhibit an important interpersonal variability. Therefore, conventional release testing methods do not allow an accurate measurement of the amount of drug released in vivo on the ocular surface region [18,39]. To prevent the drug release related to erosion and compare, from an unbiased point of view, the relatively absolute diffusion profiles of formulations A, B, and C, the adapter for semisolid forms was also used in our work.…”