Formulation development, rheological characterization, and cosmetic evaluation of gel-creams

Abstract: Oil in water (o/w) emulsions are thermodynamically unstable systems composed of small oil droplets dispersed in a continuous aqueous phase. This means that given enough time, the two phases will separate. Pharmaceutical emulsions are used as a method of administering the Active Pharmaceutical Ingredient (API) for topical applications. The API for this project will be dissolved in the aqueous phase. If the phases are to separate, the concentration of API will not be homogenous throughout product, which will alter the effect of the pharmaceutical. Therefore, the stability is crucial for the effect of a pharmaceutical emulsion. The stability as well as cosmetic properties of an emulsion is affected by several different properties, referred to as Critical Quality Attributes (CQAs). These are attributes that directly influence the quality of a product. The CQAs are in turn affected by Critical Process Parameters (CPPs) which are specific parameters during the manufacturing process. To ensure a high-quality product with little variation between batches, the CPPs for manufacturing are to be identified, evaluated, and monitored. In this project the temperature during manufacture, polymer quality, and homogenization speeds will be evaluated as CPPs and their effect on CQAs modelled using a Design of Experiments. From the models it was found that the homogenization speed is most critical to the formulation process, but further work is required to properly model how polymer concentration and temperature affect CQAs.