Physical characterization of non-sterile liquid preparations: appearance

• Autor(a) principal: Dias, Daniela Filipa Santos
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/27487
• topic: Drug Product; Appearance; Color Spaces; Visual and Instrumental Evaluation; Color Tolerances

The present dissertation consists in the development of a visual and instrumental method for the evaluation of the color of a non-sterile liquid formulation. The color of the formulation was analyzed at different time intervals, after being subjected to different conditions of temperature and relative humidity in its pre-stability period. The evaluation occurred by comparing the formulation with different color scales reproduced based on the European Pharmacopoeia 9.7. Due to the fact that the visual assessment could be subjective, an instrumental color evaluation was performed from three- and two-dimensional color spaces, namely the CIELAB color space. Since the two-dimensional representation used to the instrumental specification of color does not consider all the attributes associated with color (does not include brightness), the CIELAB Difference (ΔE∗) between the color of the standard solutions of the scales and the formulation analyzed under different conditions was determined. The CIELAB Difference between two colors considers all the parameters that influence the color sensation and allows determining which of the standard solution has the most similar color to the formulation under analysis. Finally, using the standard solution with the most intense color of one of the scales reproduced, a rectangular color tolerance box was established to limit the acceptable tolerance for the coordinates of the formulation under analysis: all the formulations with the color coordinates outside the tolerance limits should be potentially rejected and investigated. However, the tolerance defined with the most intense color of one of the scales is merely representative: the main objective is, over time, to obtain a history of the coordinates of the color of the formulation and establish as tolerance limit the coordinates of the color associated with a formulation that is at the limit of the specifications associated with it