Objectives The human eye is a unique and intricate structure which has made drug delivery to the eye a formidable undertaking. Anterior-segment eye diseases are ubiquitous, especially among elderly patients, and conventional eye drops, although a first-choice dosage form, are not always an efficient treatment option. The development of novel drug delivery systems for improved treatment is therefore imperative. Key findings In an attempt to circumvent the obstacles presented by the structure of the eye, advanced systems such as ocular mini-tablets have been developed. In this review, a concerted effort has been made to provide a detailed overview of topically administered ocular mini-tablets and other solid devices for drug delivery to the anterior segment of the eye. These mini-tablets have been shown in vitro and in vivo to have significant advantages in comparison with liquid preparations. This is a step toward attaining better patient convenience and compliance, which are critical factors. Summary Solid ophthalmic dosage forms have several advantages that can contribute to assisting with patient compliance and, ultimately, effective disease treatment. In addition to the challenges associated with topical ocular drug delivery, the shortcomings of conventional eye drops, advantages of mini-tablets, and improvements to date to these systems are discussed. The requirement for further advancements in the ocular field is also emphasized.

No abstract

Ocular diseases of the anterior segment of the eye are increasing and the development of novel drug delivery systems for improved treatment is necessary. The aim of this study was therefore to design and evaluate an instantly-soluble solid eye drop (ISED) for topical ophthalmic drug delivery of the model drug timolol maleate. The porous nature of the lyophilized ISED resulted in rapid fluid ingression, immediate hydration, and dissolution of the ocular matrix. The ISED was lyophilized employing hydroxypropylcellulose and pluronic® F68 as the matrix forming polymers. Polyacrylic acid sodium enhanced the solubility of the ISED, di-glycine, an anti-collapsing agent, while maltodextrin improved the matrix resilience. A statistical design was employed for optimizing the texture, disintegration, and the mean dissolution time (MDT) of the ISED. Results revealed that a robust rapidly disintegrating ISED was produced with the fastest disintegration time recorded at 0.20 s and drug release between 79 and 96%. In addition, improved corneal drug permeation was observed compared to pure timolol dispersion. The maltodextrin concentration significantly affected the ISED matrix resilience (p = 0.007) and pluronic F68 had a greater impact on disintegration time (p = 0.000) and MDT (p = 0.000). The ISED formulation may be a promising alternative to the use of liquid eye drops for topical ophthalmic drug delivery.

The COVID-19 pandemic precipitated the burgeoning of online learning and asynchronous online discussion forums in higher education due to restrictions on face-to-face teaching and learning interactions. Previous research on asynchronous online discussion forums focused on the processes that enhance or limit discussion threads and how discussion posts develop students' reflection and critical thinking skills. Although asynchronous online discussion forums are regarded as spaces for interactive learning, very little is known about how they facilitate epistemological access and enable collaborative peer learning interactions during periods of disruption such as the COVID-19 pandemic. The current study explores voluntary asynchronous online discussion forum participation in a non-credit bearing course from a unique angle of mediating epistemological access to online learning. This study draws on connectivist theory as a theoretical framework in a digital age where the student is in control of engagement interaction and information exchange. The central research question posed is how does an asynchronous online discussion forum mediate epistemological access to online learning and facilitate collaborative self-directed peer learning during the COVID-19 pandemic? The present study is underpinned by an inductive qualitative exploratory case study approach. A total of 2 146 discussion posts from 1 348 students across five faculties were downloaded from the learning management system and analysed using thematic analysis. This study indicates that epistemological access using a technology-mediated tool, is best facilitated through agency at the institutional, the instructor and the student level. The findings show that despite academic and technological challenges an online discussion forum enables epistemological access, interactive exchange of information and the formation of collaborative peer learning communities. In an age of digital inequalities, this study provides a starting point to uncover ontological barriers to epistemological access to online learning and signals the importance of integrating epistemological access, pedagogy and technology. This article concludes with implications for re-imagining the design of online multimodal pedagogy to mediate online collaborative self-directed peer engagement and learning. MoosaMediating epistemological access through asynchronous online discussion forums during the COVID-19 pandemic 118