Two Formulations of Venlafaxine are Bioequivalent when Administered as Open Capsule Mixed with Applesauce to Healthy Subjects

Venlafaxine is a unique antidepressant approved for treatment of various depressive disorders. A single dose, cross-over bioequivalence study was performed with two different formulations of venlafaxine 150 mg extended-release capsules in which the contents of capsule were mixed with applesauce and administered to healthy subjects under fed condition. A total of 24 healthy adult male subjects participated in this randomized, single-dose, non-blinded, two-way crossover study conducted at a single centre and 23 subjects completed the study as per the study protocol. After an overnight fast of 10 h, a high-fat and high-calorie breakfast was served 30 min before dosing. The subjects then received a single dose of either formulation administered with apple sauce followed by 240 ml of water as per randomized schedule in each period separated by a washout period of 7 days. A series of blood samples were collected upto 72 h for estimation of venlafaxine and its active metabolite, O-desmethylvenlafaxine. The quantification of venlafaxine and O-desmethylvenlafaxine was done by LC-MS/MS method and pharmacokinetic and statistical analysis by WinNonlin(®) 5.2 and SAS(®) 9.1.3. The results of the study demonstrated bioequivalence of two formulations as the 90% confidence interval for the intra-individual mean ratio of log-transformed C(max), AUC(0-t) and AUC(0-inf) of the test to the reference formulation were found within the defined bioequivalence range of 80.00%-125.00%. Both the formulations were well tolerated. This alternative mode of administration may provide benefits to patients who have difficulty in swallowing the capsule as a whole.