Formulation, development and evaluation of duloxetin delayed released capsules

Abstract

The present aim of this work is to formulate and evaluate multiple unit particulate system of Duloxetine

hydrochloride Capsules 60 mg, release profile of the dosage form and to compare with the innovator product,

determine the best fit dissolution profile for dosage form and stability study. To know about innovator’s product

and gives an idea about the excipients to be used and what not to use, market value of the product and helps in

identifying the generic companies. The work was carried out to delay the release of Duloxetine hydrochloride

by using different enteric polymers like Acryl EZE, HPMC phthalate HP 55, HPMC phthalate HP 55 S, HPMC

phthalate HP 50.With Acryl EZE only 5% drug release was observed in pH 5.5 phosphate buffer even after 90

minutes. The Enteric coating suspension was very viscous and the process was very slow when HPMC phthalate

HP 55 S was used as enteric polymer. HPMC Phthalate (HP 55) showed poor drug release in pH 5.5 phosphate

buffer, where as the drug release pattern with HPMC phthalate HP 50 was high when compared to innovator. So

a combination of HPMC Phthalate (HP 55) and HPMC Phthalate (HP 50) were used. Here Different ratios of

HPMC Phthalate (HP 55) and HPMC Phthalate (HP 50) were tried out. The release profile of E12 formulation

matched with that of the innovator product (HP 55: HP 50=6:4).Different solvent systems like IPA/DCM-1:1,

Acetone/water in the ratio 1:1 and 8:2 were tried out as enteric solvents. Acetone/water in the ratio 8:2 was

optimized. The Different kinetic models were applied to optimized enteric coated formulation (E12) and

observed that it follows zero order kinetics with Higuchi diffusion mechanism. Then the Stability studies were

conducted at 40ºC / 75% RH (accelerated stability testing) for 2 months. Assay, acid resistance, dissolution

release profile of optimized enteric coated formulation (E12) complies with that of innovator product and was

found to be stable.