Blending end point

NIR methods are not the only on-line applications for blend monitoring FT-Raman " and laser induced fluorescence (LIF) have been utilized. Refer to Chapter 11 for a comprehensive review of LIF. As stated herein, NIRS is well established as an effective and advantageous means to deem blend homogeneity and blending end point, however there are circumstances in which NIR is insufficient. For example, LIF can be more suitable for blends with low drug load. Lai and Cooney illustrated in a lab-scale experiment that LIE yielded a limit of detection below 0.02% w/w for a given API. ... 

Z. Shi, R. P. Cogdill, S. M. Short, and C. A. Anderson, Process Characterization of Powder Blending by Near-Infrared Spectroscopy Blend End-Points and Beyond, /. Pharm. Biomed. Anal., 47, 738 (2008). 

B. Igne, S. Talwar, J.K. Drennen, and C.A. Anderson. On-line Monitoring of Pharmaceutical Materials Using Multiple NIR Sensors—Part II Blend End Point Determination, ]. Pharm. Innov., 8,1, 45-55 (2013). 

Ft. Wu, M.A. Khan, Quahty-by-design (QbD) An integrated approach for evaluation of powder blending process kinetics and determination of powder blending end-point. Journal of Pharmaceutical Sciences, 98,2784-2798, 2009. 

Phthahc resins are usually processed to an acid number of 25—35, yielding a polymer with an average of 1800—2000. The solution viscosity of the polymer is usually followed to ascertain the polymer end point. The resin is cooled to 150°C and hydroquinone stabilizer (150 ppm) is added to prevent premature gelation during the subsequent blending process with styrene at 80°C. The final polymer solution is cooled to 25°C before a final quaUty check and dmmming out for shipment. 

Alkylation, where the olefins are reacted with isobutane to make a very desirable gasoline blending stock. Alkylate is an attractive blending component because it has no aromatics or sulfur, low vapor pressure, low end point, and high research and motor octane ratings,... 

Typically, for batch processes such as blending or drying, this entails the determination of process end-point attributes. The PAT method then becomes the centerpiece of the scale-up effort. Process scale-up can be undertaken under the assumption that the relationships between observables and performance are independent of scale, and if this assumption is verified in practice, the manufacturing process in full scale can be monitored (typically, to completion) providing a higher level of assurance that the product is likely to be within compliance. 

In case 1 a binary mixture of fine and coarse granules was blended to a satisfactory end-point. The blend was next emptied into a bucket elevator and thence to a hopper through a central feed point. The material was then fed, in 60 kg lots, to an extruder to produce an unacceptable finished product. The process started with a mixing operation followed by a segregating operation in the hopper. The central region (core) of the hopper contents was rich in fines and the outer regions rich in coarse, hence the initial feeds to the extruder contained an excess of fines whereas later feeds contained an excess of coarse. Since a bimodal mixture such... 

Base stock consistency control is the secret to first pass yield, i.e., meeting finished product specification limits with the specified blend of base stocks. Most finished shortenings physical characteristics are controlled with solids fat index (SFI) iodine value (IV), and/or a melting point analysis. However, time restraints during hydrogenation do not allow the long elapsed times required for these results. More rapid techniques to control base stock end points are ... 

Comparative laboratory evaluations of silica-alumina, silica-magnesia, and activated-clay catalysts have been confirmed by performance characteristics in pilot-plant and commercial operations (5,51,100,131,236,274). The important differences are illustrated in Table XII, which shows data obtained in a pilot plant when cracking a mixture of virgin and coke-still gas oils derived from West Texas crude. The blend contained about 10% of material boiling just below the end point of gasoline. 

For example, Martire and Riedl proposed some years ago that is c dculable solely from the end-points of what amoimt to (straight-line) plots of equation 14a (i.e., equation 15b), provided that the two solvents are identic d in adl respects (yield ideal solutions) save that one or the other complexes with the solute (35). Such systems include chloroform with the stationary phases n-heptadecane + di-n-octyl ether, for which the activity coefficient either solvent component (i = B or C) in the blend M (= B +... 

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