DDSolver is a freely available add-in program for Microsoft Excel designed to facilitate the modeling and comparison of drug dissolution profiles. It provides a model library with 40 dissolution models and supports various statistical methods for analyzing dissolution data, including nonlinear optimization, exploratory data analysis, univariate ANOVA, ratio tests, difference factor $ f_1 $, similarity factor $ f_2 $, Rescigno indices, 90% confidence interval (CI) of difference method, multivariate statistical distance method, model-dependent method, bootstrap $ f_2 $ method, and Chow and Ki's time series method. The program simplifies the process of fitting dissolution data to models and assessing the similarity between dissolution profiles. It uses the Nelder-Mead simplex algorithm for nonlinear optimization and allows users to define initial parameters through various methods such as linear regression, trial and error, and empirical estimation. DDSolver also includes user-defined functions for characterizing drug release curves and assessing dissolution profile similarity. The program is compatible with Microsoft Excel and has been validated using published data, demonstrating its reliability in analyzing dissolution data. It is a versatile tool for pharmaceutical scientists to perform complex calculations and comparisons efficiently.DDSolver is a freely available add-in program for Microsoft Excel designed to facilitate the modeling and comparison of drug dissolution profiles. It provides a model library with 40 dissolution models and supports various statistical methods for analyzing dissolution data, including nonlinear optimization, exploratory data analysis, univariate ANOVA, ratio tests, difference factor $ f_1 $, similarity factor $ f_2 $, Rescigno indices, 90% confidence interval (CI) of difference method, multivariate statistical distance method, model-dependent method, bootstrap $ f_2 $ method, and Chow and Ki's time series method. The program simplifies the process of fitting dissolution data to models and assessing the similarity between dissolution profiles. It uses the Nelder-Mead simplex algorithm for nonlinear optimization and allows users to define initial parameters through various methods such as linear regression, trial and error, and empirical estimation. DDSolver also includes user-defined functions for characterizing drug release curves and assessing dissolution profile similarity. The program is compatible with Microsoft Excel and has been validated using published data, demonstrating its reliability in analyzing dissolution data. It is a versatile tool for pharmaceutical scientists to perform complex calculations and comparisons efficiently.