Formulation, Characterization and Optimization of Transdermal Patches of Venlafaxine Hydrochloride Using 32 Full Factorial Approach

Introduction: The primary objective of the present investigation was to develop transdermal patches that would extend the half-life of Venlafaxine Hydrochloride and boost its bioavailability. Transdermal patches were made with Ethyl Cellulose (EC) as the lipophilic component and Hydroxypropyl Methylcellulose (HPMC K15M) as the hydrophilic matrix. Objectives: The objectives of the present study it to develop effective transdermal patches for Venlafaxine Hydrochloride delivery, optimize their formulation using different polymer ratios and evaluate their quality and drug release properties. Materials and Method: The ideal design matrix was constructed using a 32 full factorial approach, which changed the ratio between the hydrophilic and lipophilic matrices. Three different EC and HPMCK15M ratios were used to obtain the best possible formulation. Results: The thicknesses of the transdermal patches varied from 0.514±0.004 mm to 0.697±0.004 mm. The produced transdermal patches had an average weight ranging from 194.67±0.578 mg to 241.67±1.528 mg. There were variations in the moisture content of the transdermal patches. All the transdermal patch formulations exhibited uniform drug content and with a minimum variability within the batch. Conclusion: The drug content ranged from 94.7±0.6% to 97.33±0.208%. The in vitro drug release study depicted that the highest amount of drug was released from P9 (88.21±1.286%) while the lowest was released from P5 (56.47±1.066%) at the end of 24 hr of release study.