Abstract
Purpose:
Whether to enhance hydration and lubrication of the eye, promote wound healing, or extend drug residence time, the benefits of incorporating hyaluronic acid (HA) in ophthalmic formulations are well documented. However, as the delicate structure of the eye requires highly pure and safe components, the demand for HAs with very low impurity levels is increasing. Novozymes Biopharma addresses this need with a new biosynthetic HA obtained by the fermentation of the non-pathogenic strain Bacillus subtilis. Unlike previously established production methods, their Bacillus-based process does not employ any animal-derived raw materials or organic solvents and yields an extremely pure HA product characterized by very low protein and endotoxin levels. In this work, we demonstrate advantages of using Bacillus-derived HA for eye care and ophthalmic drug delivery.
Methods:
Corneal tolerance was evaluated by confocal laser scanning ophthalmoscopy. HA compatibility with diclofenac was assessed by monitoring HA molecular weight using GPC combined with triple-angle light scattering and refractive index detection (RID) and by following diclofenac stability by HPLC (UV 280 nm). HA stability during autoclaving was studied by monitoring HA molecular weight by SEC-MALS combined with RID and dynamic viscosity before and after autoclaving.
Results:
Results show that repeated applications of Bacillus-derived HA-containing formulations onto the cornea of rabbit eyes do not induce corneal lesions. Good compatibility profiles between this HA and diclofenac were observed in model ophthalmic formulations as evidenced by the excellent retention of both HA molecular weight and diclofenac integrity over 84 weeks. Furthermore, Bacillus-derived HA demonstrates superior stability during autoclaving when compared to a competitor HA product.
Conclusions:
The high purity and biocompatibility of Novozymes’ HA combined with its compatibility with ophthalmic drugs such as diclofenac and its superior stability during autoclaving makes this novel HA an ingredient of choice for formulations intended for eye care and ophthalmic drug delivery.
Keywords: 486 cornea: tears/tear film/dry eye •
557 inflammation