Preparation of the Diclofenac Sodium pH Sensitive Gel for Eyes

Objective: To prepare the diclofenac sodium pH sensitive gel for eyes (DS-pH sensitive gel). Methods: It’s used for the index that viscosity under non-physiological conditions and physiological conditions were less than 1100mPa·s and more than 2500mPa·s respectively, the dosage ranges of Carbopol 980 and HPMC were screened. The formula of DS-pH sensitive gel was optimized by orthogonal test. Results: The best formula contained Carbopol 980 0.35g, HPMC 1.0g, ethylparaben 0.01 g, mannitol 5g, diclofenac sodium 100mg, and water for injection 100mL. Conclusion: The DS-pH sensitive gel was prepared successfully.