Research Matters

The new RH95 Humidity Controller 

The new RH95 Humidity Controller 

When an opportunity arises the Linkam team like to get involved in research using our equipment.

Caroline Feltham, from our sales and marketing department, has been working with Vincent Larat — a Raman application scientist with HORIBA Scientific — using the new RH95 Humidity Controller for pharmaceutical analysis. They successfully profiled the changes that occur in the hydration state of anhydrous lactose and theophylline when samples are maintained at 95% relative humidity (RH) and 25°C.

The structural properties of pharmaceutical formulations can be altered when they are exposed to warm and humid conditions, for example during storage or in tropical countries. Ingredients may undergo changes in their hydration level, which can lead to a change in form and can have a significant effect on the efficacy of the drug.

It is important therefore, that the physical and structural properties of the active and inactive ingredients (and their interactions) are fully analysed before the drug is introduced to the market.

Anhydrous lactose is found as an inactive ingredient in a variety of different medications. It is useful as it contains no water, meaning it will not react with medications that are sensitive to moisture. But it is vital to understand the conditions at which anhydrous lactose converts to its monohydrated form, as this will interact differently with the other ingredients.

Theophylline is a menthylxanthine drug used in therapy for respiratory diseases. Hydration state affects the solubility, and consequently the bioavailability, of theophylline.

The combined use of Raman microspectroscopy (performed on the LabRAM HR Evolution from HORIBA Scientific), and a Linkam Scientific temperature and humidity control cell, allowed for accurate mapping of the point of transformation from the anhydrous form to monohydrated form. 

The full article can be found here

By Frances Coles