China
Africa
Explore chapters and articles related to this topic
Technical Support for the SPF Contractor
Published in Mark T. Bomberg, Joseph W. Lstiburek, Spray Polyurethane Foam in External Envelopes of Buildings, 2018
Mark T. Bomberg, Joseph W. Lstiburek
Friability (brittleness). When running a fingernail over the surface one may sense a presence of fine powder. Since an initial friability may be associated with a curing process, the same operation should be repeated two days later. (Excessive friability may also indicate that the SPF system is not suitable for a low application temperature.).
Particle Characterization and Dynamics
Published in Wen-Ching Yang, Handbook of Fluidization and Fluid-Particle Systems, 2003
The assessment of the material’s strength is commonly based on so-called friability tests or attrition tests (cf. Sec. 4), in which a single particle or a bulk sample of the material is for a certain extent subjected to a specific stress. Data from these tests are usually presented as single numbers called friability or attrition indices. Most of these numbers are derived from a comparison of the material’s content of a previously defined fraction of fines before and after the test (British Materials Handling Board, 1987; Davuluri and Knowlton, 1998). A frequently quoted example is the Hardgrove Grindability Index, which was originally developed to assess the grindability of coal. It measures the generation of material less than 74 microns produced in a ball-ring pulverizer during 60 revolutions on a sample with a size range between 590 and 1190 microns (cf. ASTM D409–71).
Formulation development and evaluation of orodispersible tablet of Azelnidipine by factorial design and its comparison with the marketed formulation
Published in Particulate Science and Technology, 2023
Ramdas T. Dolas, Pooja D. Ware
The tablets from all trial batches were off-white round convex-shaped beveled edges with plane upper and lower sides. The thickness and diameter for all the tablets were measured by using Vernier caliper by picking the tablets randomly. The thickness values were almost uniform in all formulations. Thickness was found in the range from 3.85 ± 0.02 to 3.87 ± 0.05 mm, respectively and diameter was found in the range of 9.10–9.12 mm. Uniformity in the values indicates that formulations were compressed without sticking to the dies and punches. Hardness for all the batches and results were expressed in Table 6. Hardness was found to be in the range of 3.5–5 kg/cm2. The hardness for all formulated batches was uniform and possess good mechanical strength with sufficient hardness. The factors that cause tablets to chip, cap, or shatter are friction and shock. The friability test is linked to tablet hardness and is used to assess a tablet’s ability to tolerate abrasion during packing, handling, and shipping. The Roche Friabilator was used to measure it (Arora and Sethi 2013). Tablets from all batches were evaluated by using Roche Friabilator and the friability of tablets was observed in the acceptable range of 0.33–0.76 (<1%). The result was given in Table 6. Tablets were prepared using the direct compression technique. Since the material was free-flowing, tablets were obtained of uniform weight due to uniform die fill. The tablets for all prepared batches were obtained in the range with acceptable weight variations as per pharmacopeia specifications of <7.5% (Table 6).