Optive Fusion/Optive Fusion UD Mechanism of Action

Pharmacology: Pharmacodynamics: No clinical pharmacology studies were performed with Optive Fusion/Optive Fusion UD.
Carboxymethylcellulose sodium has no pharmacological receptor-mediated properties. The mode of action of carboxymethylcellulose sodium is based on its physical properties which provide a lubricant effect and prolonged residence time in the eye. Carboxymethylcellulose sodium increases tear viscosity and has pseudo-elastic (i.e. shear thinning) properties. Since carboxymethylcellulose sodium is an ionic polymer containing carboxyl and hydroxyl groups, its chemical structure is similar to mucin in the tear film, and thus it has mucoadhesive properties. These properties promote prolonged residence times in the eye which alleviate the symptoms of tear deficiency. In the US, carboxymethylcellulose is described as an ophthalmic demulcent; an agent which is applied topically to the eye to protect and lubricate mucous membrane surfaces and relieve dryness and irritation.
The mode of action of glycerin in eye drops is based on its physical properties. It has no pharmacological receptor-mediated properties. In the US, glycerin is described as an ophthalmic demulcent - an agent which is applied topically to the eye to protect and lubricate mucous membrane surfaces and relieve dryness and irritation.
Pharmacokinetics: No ocular pharmacokinetic studies have been performed. Since carboxymethylcellulose sodium is pharmacologically inert and not absorbed systemically, it is not expected that safety concerns will arise from the topical administration of Optive Fusion/Optive Fusion UD.
Glycerin is a 3-carbon alcohol that is naturally occurring in the human body. Glycerin is rapidly absorbed in the intestine and the stomach, distributed over the extracellular space and excreted. It is metabolized to glucose and glycogen and may also combine with free fatty acids to form triglycerides which are distributed to adipose tissue where cell turnover occurs. Systemic intoxication from topical overdose is not expected given the low systemic exposure of glycerin via topical administration of Optive Fusion/Optive Fusion UD.