Quality assessment of the magistral ointments and creams containing urea
Magdalena Wróblewska, Mariola Kubik, Katarzyna Winnicka
Zakład Farmacji Stosowanej, Uniwersytet Medyczny w Białymstoku
Introduction. Urea is a compound commonly used in cosmetic and pharmaceutical preparations. It possesses multidirectional, concentration-dependent activity and it is regarded as one of the most effective moisturizing ingredients.
Aim. The aim of the study was to assess the quality of magistral preparations with urea made using different bases and analysis of the stratum corneum hydration effectiveness after a single application of prepared formulations.
Material and methods. Creams and suspension-type ointment were prepared using unguator machine with various ointment bases. The concentration of the urea corresponded to its concentration in commercially available products. The quality of formulations was estimated by pH measurement, evaluation of mechanical properties and in case of suspension-type ointment - particle size was analyzed by a microscopic method. The degree of the stratum corneum hydration after a single application of prepared formulations was conducted within a group of 6 volunteers using corneometer.
Results. The strongest moisturizing effect on the stratum corneum after a single application of prepared formulations was noted in the case of creams based on eucerin and lekobaza lux, and the moisturizing effect was concentration-dependent. The pH values of prepared formulations were in the range 3.56-7.21. The analyzed preparations possessed similar textural properties, with the exception of the hydrophilic petrolatum cream. The particles size in suspension-type ointment was lower than 90 µm.
Conclusions. Formulations based on eucerin and lekobaza lux demonstrated the best moisturizing effect after a single application. In the case of the cream prepared with hascobaza low pH value was noted, unfavorable because of the stability of urea. Cream prepared with hydrophilic petroleum possessed high values of textural parameters which might negatively affect its application properties.
Key words: urea, hydration of the skin, magistral ointments, textural properties