Background:
Venlafaxine HCl is a selective serotonin reuptake inhibitor which is given in the
treatment of depression. The delivery of the drug at a controlled rate can be of great importance
for prolonged effect.
Objective:
The objective was to prepare and optimize the controlled release core in cup matrix
tablet of venlafaxine HCl using the combination of hydrophilic and hydrophobic polymers to
prolong the effect with rate controlled drug release.
Methods:
The controlled release core in cup matrix tablets of venlafaxine HCl were prepared
using HPMC K5, K4, K15, HCO, IPA, aerosol, magnesium sterate, hydrogenated castor oil and
micro crystalline cellulose PVOK-900 using wet granulation technique. Total ten formulations
with varying concentrations of polymers were prepared and evaluated for different
physicochemical parameters such FTIR analysis for drug identification, In-vitro drug dissolution
study was performed to evaluate the amount of drug release in 24 hrs, drug release kinetics study
was performed to fit the data in zero order, first order, Hixson–crowell and Higuchi equation to
determine the mechanism of drug release and stability studies for 3 months as observed.
Results:
The results of hardness, thickness, weight variation, friability and drug content study
were in acceptable range for all formulations. Based on the In vitro dissolution profile,
formulation F-9 was considered to be the optimized extending the release of 98.32% of drug up
to 24 hrs. The data fitting study showed that the optimized formulation followed the zero order
release rate kinetics and also compared with innovator product (flavix XR) showed better drug
release profile.
Conclusion:
The core-in-cup technology has a potential to control the release rate of freely water
soluble drugs for single administration per day by optimization with combined use of hydrophilic
and hydrophobic polymers.
METOPROLOL—CONTROLLED RELEASE, ZERO ORDER KINETICS
