Hot Melt Extrusion Essay Example | Topics and Well Written Essays - 750 words

Hot Melt Extrusion - Essay Example HME technique does not require time consuming drying step and compressing step; and therefore, the processing steps are significantly reduced. Due to fewer unit operations involved in HME operation, production time is greatly enhanced. During the HME process, the polymer-melt itself act as a thermal binder. HME eliminates problems arising from poorly compactible materials. An extruded rod obtained from HME procedure can be directly incorporated into tablets after cutting. Uniform dispersion of fine particles is obtained due to vigorous mixing and agitation conditions of HME operation. The energy requirements in HME process are low as compared to high shear granulation. The HME process requires lower investment for equipment as against other processes. HME technique also provides new strategies to increase dissolution rates for sparingly water soluble drugs, enhance bioavailability of the active ingredient, improve content uniformity of dosage formulation, modify drug release, and als o helps to mask the unpleasant taste of the drug (Repka et al. 1043; Crowley et al. 909). A single- or twin-screw extruders are used for HME process. The extruder is composed of a feeding hopper, barrels, single or twin screws, die, screw-driving unit, heating/cooling device for the barrels, conveyer belt to cool down the product, and solvent delivery pump. The monitoring devices on the equipment include temperature gauges, a screw-speed controller, an extrusion torque monitor and pressure gauges. During the HME process, first a dry powder blend of drug, polymer, and other adjuvants/additives is prepared. Then, this soild mixture is fed into the feeding section of the extruder. The material is transferred to the melting section. The heat is applied to the material in the melting section to form the polymer-melt. This molten mass is transferred in the metering section which is then