Diquafosol (tradename Diquas) is a pharmaceutical drug for the treatment of dry eye disease that was approved for use in Japan in 2010; it is formulated as a 3% ophthalmic solution of the tetrasodium salt for topical ocular instillation and is typically dosed multiple times per day. Its mechanism of action involves agonism of the P2Y2 purinergic receptor on conjunctival epithelial cells and goblet cells, activating a Gq/PLC/IP3 signaling cascade that elevates intracellular calcium, promotes chloride and fluid transport across the ocular surface epithelium, and stimulates mucin secretion from goblet cells. These combined effects increase both the aqueous and mucin components of the tear film, improving tear film stability and reducing tear film breakup time. Pharmacologically, diquafosol is a charged dinucleotide-type agent formulated with buffering and tonicity components to maintain ocular compatibility; it is evaluated for sterility, endotoxin limits, and ophthalmic tolerability in clinical use.
Parent: Diquafosol
Parent: Diquafosol
Typical quality specifications for the diquafosol tetrasodium active pharmaceutical ingredient and the finished 3% ophthalmic solution control organic and inorganic related substances, residual solvents, heavy metals, and microbiological attributes. Representative impurity limits used in regulatory dossiers are: individual specified related compounds such as dephosphorylated or hydrolyzed dinucleotide species not greater than 0.20 to 0.30% w/w each; unspecified individual organic impurities not greater than 0.10 to 0.20% w/w; total identified organic impurities not greater than 0.8% w/w and total organic impurities not greater than 1.0% w/w. Inorganic and elemental limits typically include heavy metals below 10 ppm by ICP-MS and inorganic phosphate/sodium counterions controlled by assay. Residual solvents are controlled to ICH Q3C class limits with ethanol typically below 0.5% v/v and class 1 or 2 solvents absent or below their permitted daily exposures. The ophthalmic product specification also includes sterility per pharmacopoeial methods, bacterial endotoxin limits appropriate for ophthalmic solutions (commonly <0.5 EU/mL), and potency assay by validated HPLC or LC-MS methods for both assay and related-substance profiling.
Diquafosol is used to treat dry eye disease by increasing tear volume and mucin secretion on the ocular surface; it is indicated for patients with tear film instability where improving both aqueous and mucin layers can restore tear film function.
Diquafosol is a P2Y2 receptor agonist that activates Gq-coupled signaling in conjunctival epithelial cells and goblet cells, raising intracellular calcium via phospholipase C and IP3, which stimulates apical chloride and water transport and induces mucin release from goblet cells, thereby enhancing tear film stability.
The marketed formulation is a 3% w/v ophthalmic solution of the tetrasodium salt (tradename Diquas); in clinical practice the product is administered as topical ocular drops several times per day following the prescribing information and local regulatory approvals.
