Purging agents

Castor oil is a bland oil that is hydrolyzed in the gut to yield ricinoleic acid, the active purging agent. This hydrolysis requires bile, a fact that is sometimes overlooked when castor oil is given as a laxative before radiography in biliary obstruction. The ricinoleic acid acts on the ileum and colon to induce an increased fluid secretion and colonic contraction. 

Da Huang is a very good purgative agent compared with such agents in western medicine. It stimulates the intestines and purges the bowels without severe cramp. The purgative effect appears... 

The combined dosages of Fu Zi and Xi Xin are larger than that of Da Huang. Thus the nature of the formula is warm and Da Huang is used mainly as a purgative agent. 

Rituximab is being evaluated in the setting of autologous HSCT. It is given pretransplant as an in vivo purging agent prior to stem cell collection. In other studies, rituximab is given as posttransplant consolidation. 

Vista Purge Dryblend. [Vista] PVC dryblend extruder purging agent. 

In the case of ASA/PVC blends Geloy ), the melt temperature should not exceed 200°C for more than 1 minute, to avoid PVC degradation. Furthermore, the total time at the recommended processing conditions should never exceed 5 minutes. PS is the best purging agent. 

Table 5.14 Examples of purging agents when changing plastic compound in a plasticator...

Ground/cracked cast acrylic and PE-based materials are the main purging agents, but others also are commercially available for certain machines and materials. Cast acrylic, which does not melt completely, is suitable for virtually any resin. About one pound for each ounce of injection capacity will be needed (5-10 Ib/in. of screw diameter in an extruder). With extruders, special conditions and preparations are required, which suppliers of the purging compound can recommend (remove dies, screen packs, etc.). 

These purging agents function by mechanically pushing and scouring residue out of the machines. Others also apply chemical means. Tables 2-6 and 2-7 provide information on purging. 

Asaclean, High-performance purging agent. Sun Plastech Inc. 

Pureline, FEP-lined LDPE mbing, Furon Co. Pui ex Blends, Purging agents, Neutrex Purgex Concentrates, Purging compound, Neutrex... 

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