Blistering mechanism

Spiros n/a 1, 16, or 30 Unit dose blister Mechanical Turbulence, impaction,... 

Diseus Glaxo Multidose blister Mechanical, patient inspiration... 

Diskhaler Allen and Hanburys (now Glaxo) Asthma, COPD Multidose blister Mechanical, patient inspiration Yes... 

Spiros Dura Multidose blisters Mechanical, not driven by patient inspiration 1 = o as. S oi re o —... 

SEM studies contribute to an understanding of a major obstacle to residual solvent removal. Figure 16.1.2 shows two photographs of polyethylene strands extraded from a melt which initially contained 4000 ppm hexane. After a short period of time following the extrusion, blisters form which remain in the material and become enlarged until they break and release solvent. This blistering mechanism, determines die rate of residual solvent removal from the material. The rate of removal depends on bubble nucleation, temperature, and polymer rheological properties. ... 

Decarburization results from hydrogen absorption from gas streams at elevated temperatures. In addition to hydrogen blistering, hydrogen can remove carbon from alloys. The particular mechanism depends to a large extent on the properties of other gases present. Removal of carbon causes the metal to lose strength and fail. 

A number of skin diseases, mainly characterized by blistering, have been found to be due to mutations in genes encoding various keratins. Three of these disorders are epidermolysis bullosa simplex, epidermolytic hyperkeratosis, and epidermolytic pahnoplantar kerato-derma. The blistering probably reflects a diminished capacity of various layers of the skin to resist mechanical stresses due to abnormalities in microfilament strucmre. 

Use of NAD microgels with a low glass transition temperature improved the mechanical performance, durability and resistance against blistering of coatings for household and industrial buildings [344,345]. 

This means that the time for flow-out of the powder becomes shorter with increasing functionality of the crosslinker, with respect to the total cycle time required for reaching satisfactory film properties (mechanical, chemical. Fig. 20, step D). The reduced flow-phase time results in a poorer film surface quality. Moreover, when volatiles are set free as a result of the crosslinking reaction, in this case water, they will cause blister formation after the gel-point. Blister for-... 

D-penidllamine can promote the elimination of copper (e.g., in Wilson s disease) and of lead ions. It can be given orally. Two additional uses are cystinu-ria and rheumatoid arthritis. In the former, formation of cystine stones in the urinary tract is prevented because the drug can form a disulfide with cysteine that is readily soluble. In the latter, penicillamine can be used as a basal regimen (p. 320). The therapeutic effect may result in part from a reaction with aldehydes, whereby polymerization of collagen molecules into fibrils is inhibited. Unwanted effects are cutaneous damage (diminished resistance to mechanical stress with a tendency to form blisters), nephrotoxicity, bone marrow depression, and taste disturbances. 

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