What is the current status of drugs targeting cancer?

The manufacture of medicines must draw on expertise from a wide range of disciplines, from the initial investigation and design of a new drug or therapeutic to wide-scale production and distribution, also considering the additional quality control measures that must be upheld throughout these stages with regard to pharmaceutical products are produced in batch processes with multiple discrete steps, often necessitating lengthy storage periods while quality testing is performed or the equipment required is prepared after the previous batch. Fluctuations in demand are also difficult to respond to using batch production since the batch currently in production must be completed, and scaling up would require larger equipment. Instead, the FDA encourages drug manufacturers to switch to continuous production processes. Raw materials are fed into a fully integrated assembly line that completes the production of the desired product in a single run, allowing production to be scaled to demand quickly and efficiently. Products in the event of a recall may actually be easier during continuous production processes, products can be time-stamped with when they left the assembly line, allowing the recall of products at a particular time plus or minus a few minutes. This type of continuous manufacturing has only been made possible with modern technologies that can ensure continuous detection of quality assurance issues and technical faults. Many other chemical industries have all but made the transition to continuous manufacture where possible. The enhanced quality assurance standards of pharmaceuticals, as well as high start-up costs, have meant limited adoption of continuous manufacturing in the pharmaceutical industry, but continuous manufacturing processes have been developed for several common drugs such as ibuprofen and tamoxifen, the hormone therapy used to treat breast cancer. Another major advantage of continuous manufacturing processes is that carcinogenic drugs such as this can be produced with minimal human contact, with all chemical processes taking place internally without requiring intermediate transfer by staff. A large majority of drug manufacturing processes require a  step followed by filtration and isolation of the final product, which has presented a significant technological hurdle regarding continuous manufacture. Requires a high concentration of product in an appropriate solvent under precise conditions in order to generate crystals of the desired size, allowing them to be efficiently separated by filtration. An equilibrium between dissolved and solid compounds is reached that pushes heavily in crystal production, but this is difficult in continuous systems and results in low yields. To establish equilibrium in closed systems, the concentrated liquid drug is continuously fed into the chamber while a slurry containing the crystals is constantly removed. Chaining multiple mixing tanks with differing temperatures and other conditions allows high control of crystal formation mechanisms, and cross-flow filtration is used to ensure that only the desired crystals to pass to the next chamber. The quick turnaround time of batch 3D printing compared to setting up a dedicated facility may have particular clinical applications in early drug development and research as well as in unique and first-response situations, with obvious advantages towards medicine. Unfortunately, the hot extrusion method used to layer the 3D printed material may be damaging to many drug compounds, and numerous other technical challenges remain to be addressed.