DISSOLUTION PROFILE STUDY FOR EXTENDED RELEASE VALPROIC ACID DOSAGE FORM (DEPAKINE® CHRONO)

Dissolution profile study for extended-release valproic acid preparations was performed in three dissolution media: 0.1 M hydrochloric acid, acetate buffer pH 4.5, citrate-phosphate buffer pH 6.8 using Apparatus 1 at 75 rpm. Time points were 1, 2, 3, 4, and 6 hours. Assay of released API was performed using HPLC-UV. API did not released or slightly released in 0.1 M hydrochloric acid and acetate buffer pH 4.5 because of low solubility of valproate in acid form. Recommended dissolution medium was citrate-phosphate buffer pH 6.8 which provides high solubility, stability and complete release of API.