Enhancing the stability of cream base: emulsifiers and pH Variations for Optimization

Abstract

The solubility of active substances within dosage forms fundamentally dictates their bioavailability and therapeutic efficacy. Creams represent a vital category of pharmaceutical vehicles, particularly for water-insoluble active substances. They are prone to phase separation due to their dual-phase nature because the cream is an emulsion with a harder consistency. Notably, the stability of the cream is linked to various physicochemical properties of the active substances, including pH, oxidative, and reducing potentials. Furthermore, successfully incorporating active substances from natural extracts, Dengen (Dillenia serrata) stem bark extract, characterized by varying the extract concentrations, necessitates meticulous solvent selection to ensure optimal solubilization. In this study, we systematically investigate three distinct cream formulations, each varying in non-ionic emulsifier concentrations. Comprehensive evaluations involve subjecting these formulations to a spectrum of pH adjustments (ranging from 4 to 10) and including natural extracts. Subsequent analyses encompass organoleptic assessments, pH measurements, viscosity profiling, determination of emulsion type, and potential phase inversion occurrences. Our findings unveil homogeneous formulations across all formulations, characterized by consistent organoleptic properties, albeit with discernible alterations upon extract addition. Notably, all formulations maintain an oil-in-water (O/W) type, with no observed phase inversion. While pH and extract modifications insignificantly influence formulation stability pre- and post-accelerated testing, notable alterations in viscosity are evident, particularly in F2, which showed a significant difference between before and after the accelerated test (p <0.05). These outcomes underscore the pivotal role of pH modulation and natural extract integration in optimizing cream stability and the pharmaceutical formulation efficacy.