Ethyl Cellulose

The study aims at developing novel extended release pellets of venlafaxine. The main objective of the work was to develop robust extended release formulations of Venlafaxine (test formulation) for regulated markets having comparable in-vitro dissolution profile with Innovator product - Effexor® XR (Reference Product). Venlafaxine spheroids were made using extrusion spheronization technique. The release of the drug from the spheroids was controlled by applying a coating comprising ethyl cellulose as rate controlling polymer. The coated pellets were then encapsulated in the hard gelatin capsules. The in-vitro dissolution studies were conducted to evaluate the release of the drug venlafaxine from the coated spheroids contained in capsule at pH 6.8 using phosphate buffer. The in-vitro dissolution profile of the test compositions was compared with Reference Product Effexor XR. The results obtained showed that the test formulations had higher percentage release of venlafaxine in initial time period. Therefore, a better control on the release was desired. During the manufacturing of spheroids, it was observed that more fines were generated during the extrusion spheronization, which is not suitable for large scale production of the formulation. Accordingly batches were optimized using different types of binder and coating composition. Effect of the binder and percentage coating was studied. The drug release of venlafaxine using Povidone K30 as binder, Ethyl cellulose and Acryl-EZE MP 93018508 white as release control polymers was compared with innovator’s drug release and was found to be equivalent. From the results, it was concluded that use Povidone K30 as binder during extrusion spheronization process results on generation of less fines, thus increases the yield of the product. Also, the formulation containing dual coating of Ethyl cellulose and Acryl-EZE MP 93018508 on the spheroids containing Povidone K30 as binder showed the dissolution profile similar to that of the Reference Product Effexor XR.

The present study involves preparation and evaluation of floating microsphere of Captopril as model drug for prolongation of gastric residence time. the different gas forming agents are used such as sodium bicarbonate and calcium carbonate. The microsphere were prepared by Ionotropic gelation technique using polymers Sodium alginate along with HPMC (K4M) and Ethyl cellulose. The microsphere was evaluated for angle of repose, bulk density, tapped density, Carr’s index, Hausner's ratio, percent yield and drug entrapment. The shape and surface morphology of prepared microsphere were characterized by optical and scanning electron microscopy, respectively. In-vitro drug release studies were performed by using an USP dissolution test apparatus (type I) at 37±0.5ºC and 50 rpm speed.  To study the release behaviour, kinetic analyses were performed on the optimized formulation. The dissolution data were fitted to zero order, first order, matrix, Hixson-Crowell, Peppas model. The prepared microsphere exhibited prolonged drug release (~ 12 hr) and remained buoyant for > 12 hr.  The optimized formulations H3, H6 were kept for short term stability study. The conditions for stability study were 40ºC and relative humidity of 75% from the study; it was observed that there is no significant change in drug entrapment and drug release rate. Key-words: Floating microsphere, Captopril, In-vitro release, HPMC (K4M), Ethyl Cellulose

The present work reports the study of different Lamivudine (LAM): excipient formulations, in order to determine the effect of the polymer substitution and type of diluents on the drug-release mechanism. Seven formulations were prepared using either HPMC K15M alone or in combination with Ethyl Cellulose (EC). Release kinetics was evaluated by using United States Pharmacopeia (USP)-22 type I dissolution apparatus. The tablets were tested for their drug content, weight variation, hardness, thickness, tensile strength, friability, swelling and release ratio. Polymers HPMC K15M was found not to be appropriate for the preparation of modified release LAM hydrophilic matrix tablets, while combination of HPMC K15M and EC showed to be advantageous. The analysis of the release profiles in the light of distinct kinetic models (zero-order, first-order, Higuchi and Korsmeyer–Peppas) led to the conclusion that the concentration of polymer did not influence the release mechanism of the drug. The mean dissolution time (MDT) and t50% was determined, the highest MDT and t50% value being obtained for HPMC and EC formulations. Moreover, the drug-release process was not found to be influenced by the type of diluents, either MCC or DCP. Key words: Lamivudine, HPMC, Ethyl Cellulose