Topical ophthalmic antimicrobials: unfulfilled demands and possibility of new investments in Brazil and in the United States

In general, topical ophthalmic drug products, especially those used for treating infections, present low effectiveness because of various reasons, from unfavorable drug physicochemical properties to physiological protective mechanisms of the eye. The fact is such group of products holds room for improvement, which could mean the development of better drugs or dosage forms. To achieve this, the knowledge of market composition is essential. The present work studied and compared the antimicrobial ophthalmic markets of Brazil and of the United States (US). Official databank of Brazilian Health Regulatory Agency and of US Food and Drug Administration were assessed for registered antimicrobial topical ophthalmic drug products. Brazilian market has registered greater number of drug products (119) than the US (94), but the latter involves more variety of substances and dosage forms. In both countries, non-innovative products registered as solutions of antibacterials, especially fluoroquinolones and aminoglycosides lead the market. Despite the clinical demand, the US has only one group of antimycotics (polyenes) registered, while in Brazil, there is not any ophthalmic antimycotic product marketed. This study evidences there is not only space for development of newer drugs and formulations but also a demand for already existing technologies and products in both countries.

Novel Artificial Tears Containing Cross-Linked Hyaluronic Acid: An In Vitro Re-Epithelialization Study.

Dry eye syndrome is a common disease which can damage the corneal epithelium. It is treated with eye drops to stimulate tear production and hydrate the corneal surface. The most prescribed artificial tear remedies contain hyaluronic acid (HA), which enhances epithelial wound healing, improving tissue health. To the best of our knowledge, only a few recent studies have investigated cross-linked HA (HA-CL) in eye drops for human applications. This work consists in an in vitro evaluation of the re-epithelialization ability of two different preparations containing a recently synthetized HA cross-linked with urea: 0.02% (w/v) HA-CL (solution 1, S1), and 0.4% (w/v) HA-CL (solution 2, S2). The study was conducted on both 2D human corneal cells (HCEpiC) and 3D reconstructed tissues of human corneal epithelium (HCE). Viability by 3(4,5-dimethylthiazol-2)2,5-diphenyltetrazolium bromide (MTT) test, pro-inflammatory cytokine release (interleukin-8, IL-8) by ELISA, and morphology by hematoxylin and eosin (HE) staining were evaluated. In addition, to understand the molecular basis of the re-epithelialization properties, cyclin D1 levels were assessed by western blot. The results showed no cellular toxicity, a slight decrease in IL-8 release, and restoration of epithelium integrity when the wounded 3D model was treated with S1 and S2. In parallel, cyclin D1 levels increased in cells treated with both S1 and S2.