Table 2: Mathematical models related to dissolution experiments.

ModelEquation

Dissolution efficiency D E = ( 𝑡 0 𝑦 𝑑 𝑡 / 𝑦 1 0 0 𝑡 ) × 1 0 0 %
First-order % 𝐷 = 1 0 0 ( 1 𝑒 𝑘 𝑡 )
Biexponential % 𝐷 = 1 0 0 [ 1 ( 𝐴 𝑒 𝛼 𝑡 + 𝐵 𝑒 𝛽 𝑡 ) ]
Zero-order % 𝐷 = 𝑘 𝑡
Weibull % 𝐷 = 1 0 0 [ 1 𝑒 ( 𝑡 / 𝑇 𝐷 ) 𝑏 ]

Legend: % 𝐷 : dissolved percentage, 𝑏 : shape parameter, 𝑇 𝐷 : time interval necessary to release 63.2% of the drug, k, α and β: kinetics constants, 𝑡 : dissolution time, 𝐴 and 𝐵 : initial drug concentrations that contribute for the two dissolution stages.