Influence of Drug Incorporation, Temperature and Storage Time on the pH, Textural and Rheological Properties of Different Poloxamer Hydrogels

In recent years, Poloxamers had attracted a particular interest in the design of dermal and transdermal delivery systems in order to improve or retard drug permeation through the skin. In the present study, the influence of different parameters, such as, temperature, storage time, type of polymer (Lutrol® F-127 and Lutrol® F-108) and the addition of two types of drugs (ibuprofen and hydrocortisone) in the pH, texture and rheological behavior of topical pharmaceutical formulations containing poloxamers was assessed. In fact, the type of polymer used in the preparation of the hydrogels, the type of drug incorporated, the temperature and the storage time caused changes in the pH, texture and rheological behavior of topical formulations containing Lutrol® F-127 and Lutrol® F-108. Lutrol® F-127 hydrogels showed higher values of pH, firmness, adhesiveness and viscosity than Lutrol® F-108 hydrogels. The chemical nature of the drugs incorporated in these poloxamer hydrogels influence the pH of the preparations. Low percentages of drug incorporated into both types of hydrogels didn’t affect significantly their textural and rheological characteristics. The hydrogels prepared with Lutrol® F- 127 proved to be more resistant to temperature variations, maintaining their rheological behavior over time.