Analysis of Lactose Monohydrate by TGA-FTIR

A hydrate or a solvate is a crystalline compound whose molecules contain water or solvent molecules in a defined ratio within its crystal structure. If water is incorporated, the compound is called a hydrate. In the pharmaceutical industry, products are frequently manufactured as hydrates because their solubility in the human body is better. This article describes how a hydrate or solvate can be characterized by TGA-FTIR [1, 2] using lactose monohydrate as an example.

Introduction

Different factors must be taken into account when solid substances are developed for use in the pharmaceutical industry. The products must be pure, have good bioavailability, and be chemically and physically stable and easy to process. Furthermore, their properties such as melting point or glass transition point T_g (should not be too close to ambient temperature) and their hygroscopic behavior (uptake and retention of moisture) should be suitable. Solvates or hydrates are frequently used because they are better absorbed by the human body. This article describes how the decomposition of a hydrate or solvate can be investigated and the decomposition products characterized using a TGAFTIR combination. Lactose monohydrate was chosen as an example. The caloric effects involved were also analyzed by DSC and TGA/DSC. Lactose monohydrate is a disaccharide and has the structural formula shown in Figure 1. The substance occurs in milk and is also known as milk sugar. Lactose monohydrate is often used in the manufacture of drug substances as a diluent or excipient because it is cheap, nontoxic, and readily available

_{Analysis of lactose monohydrate by TGA-FTIR | Thermal Analysis Application No. UC 572 | Application published in METTLER TOLEDO Thermal Analysis UserCom 57}