Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Pharm Dev Technol. 2023 Oct;28(8):719-723. doi: 10.1080/10837450.2023.2238047. Epub 2023 Aug 2.
A low value of deformation before crushing is an obvious and understandable measure of brittleness of materials including tablets. In this article, three methods based on deformation measurement in a flexure tester are compared. The simplest one is a plain measurement of distance from contact or selected start point till fracture. Next the brittle-ductile method (BDI), where the distance is established by normalisation of the force-displacement curve based on the work of failure (WOF). The third method is the tablet brittleness index (TBI) by Gong and Sun, where the reciprocal of a linear distance is proposed as a brittleness quantity. The study is based on data from a previous investigation, where tablets of microcrystalline cellulose and lactose in different combinations and with four different crushing forces were utilised. The investigation shows that the BDI method is preferable. It is easy to compute without data manipulation, the sensitivity to the fracture force is negligible and it provides an independent characteristic of the brittleness of a compacted material.
压碎前的低变形值是衡量包括片剂在内的材料脆性的一个明显且易于理解的指标。在本文中，比较了三种基于弯曲测试仪中变形测量的方法。最简单的方法是从接触点或选定的起始点到断裂点的距离的简单测量。其次是脆性-延性方法（BDI），其中距离是通过基于失效功（WOF）的力-位移曲线归一化来确定的。第三种方法是 Gong 和 Sun 的片剂脆性指数（TBI），其中提出了线性距离的倒数作为脆性量。该研究基于之前的一项调查的数据，其中使用了不同组合的微晶纤维素和乳糖片剂以及四种不同的破碎力。研究表明，BDI 方法更可取。它易于计算，无需数据处理，对断裂力的敏感性可以忽略不计，并且为压实材料的脆性提供了一个独立的特征。
