Evaluation of hydrophilic, hydrophobic and waxy matrix excipients for sustained release tablets of venlafaxine hydrochloride.
OBJECTIVE
Venlafaxine is freely soluble In water and administered orally as hydrochloride salt In two to three divided doses. In the present investigation different release retarding matrices have been evaluated for sustained release of venlafaxine hydrochloride (VH) from the formulated tablets.


METHODS
Sustained release matrix tablets were formulated using different hydrophilic, hydrophobic and waxy materials as matrix formers. Tableting was done by pre-compression, direct compression and hot melt granulation depending on the type of matrix material used and evaluated for different tests. The formulated tablets were compared with commercial venlafaxine products. In vitro drug dissolution profiles were fitted In different mathematical models to elucidate the release mechanism.


RESULTS
Dissolution data showed that commercial formulations Venlor XR(®) and Venfax PR(®) released the entire drug withIn 8 h where as the formulated tablets with hydroxypropylmethylcellulose (HPMC) and cetyl alcohol as matrix formers provided sustained release of drug for 14-15 h. The release was found to follow Hixson Crowel and Higuchi kinetics for HPMC and cetyl alcohol tablets, respectively.


CONCLUSIONS
The developed matrix tablet formulations with HPMC and cetyl alcohol provided sustained release profiles for prolonged periods than commercial formulations.
Institute of Pharmaceutical Sciences, Kurukshetra University, Kurukshetra, India.
Kiran
K
Yadav
Deepak
D
Yadav
Anand Kumar
AK
Srivastava
D018687:Antidepressive Agents, Second-Generation / Q000008:administration & dosage*; D002626:Chemistry, Pharmaceutical; D003511:Cyclohexanols / Q000008:administration & dosage* / Q000032:analysis / Q000737:chemistry; D003692:Delayed-Action Preparations; D005079:Excipients / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008962:Models, Theoretical; D012995:Solubility; D013607:Tablets; D000069470:Venlafaxine Hydrochloride
D018687:Antidepressive Agents, Second-Generation; D003511:Cyclohexanols; D003692:Delayed-Action Preparations; D005079:Excipients; D013607:Tablets; D000069470:Venlafaxine Hydrochloride