in carboxylic acid: Hydroxy and keto acids. ...not the same. The 2-hydroxy acids form cyclic dimeric esters (formed by the esterification of two molecules of the acid) called lactides, whereas the 3- and 4-hydroxy acids undergo intramolecular esterification to give cyclic esters called lactones.
VBA's ActiveWorkbook property refers to the workbook with the focus. The active workbook may or may not contain the code that's referencing the active workbook, which is an important distinction. It's perfectly acceptable to use this property to reference the active workbook from code inside the active workbook.
Instead, use the ThisWorkbook class to programmatically access the workbook in your project. The ThisWorkbook class derives most of its members from the Microsoft.Office.Tools.Excel. WorkbookBase class. This class redirects all calls to its members to an internal implementation of the Microsoft.Office.Tools.Excel. Workbook interface in the Visual Studio Tools for Office runtime.