Abstract
Purpose: :
Chemical and physical stability of polyunsaturated fatty acids (PUFA) ophthalmic formulation is a very difficult challenge, the aim of our study was the development of a stable topical ophthalmic formulation containing omega 3 and omega 6 PUFA, for the treatment of ocular surface discomfort syndrome.
Methods: :
Oil solution of eicosapentaenoic acid and γ-linolenic acid in α-tocopherylacetate was mechanically dispersed in a carbomer (carbopol 980) buffered hydrogel containing low levels of high molecular weight polyacrylic acid polymer (pemulen). Osmolality, pH, oil droplet size, droplet size distribution, rabbits ocular tolerability (Draize’s test) were evaluated. Chemical (PUFAs concentrations) and physical stability were controlled under different ICH recommended conditions.
Results: :
Oil droplets were stable and showed a narrow range of distribution size 2-5 µm with an average value of 3 µm. Osmolality ranged from 140-160 mOsm/Kg and pH from 6.8-7.2. The hydrogel ophthalmic formulation showed a good particle size stability as well as a good chemical stability of the actives and excipients: the degradation of eicosapentaenoic acid and γ-linolenic acid was less then 2% after twelve months at room temperature while at 2-8 °C the formulation was stable for 24 months. The ocular tolerability evaluated by using true Draize’s test was good.
Conclusions: :
Omega 3/omega 6 hydrogel microemulsion ophthalmic formulation was shown to be stable, well tolerated and viable for a potential use in the topical treatment of ocular surface discomfort syndrome.
Keywords: cornea: tears/tear film/dry eye • development • inflammation