ABSTRACT Hair care products play a significant role in the cosmetic market and aim at improving hair brightness, breakage resistance, and color change. In this study, we analyzed the possibility of the formulation of oxidative dyes in different vehicles impacting the hair’s both mechanical and physical properties. Light brown and light blond dyes were prepared using eight different vehicles. Among these, four vehicles were emulsifying agents and four gelling agents. Each formulation was applied to two types of virgin Caucasian hair (light blond and dark brown). Physical, chemical, and organoleptic properties of each formulation were assessed, as well as changes in hair parameters after oxidative dyeing, such as staining intensity, brightness, and breaking strength. The parameters of color and brightness differed in some formulations, but the hair type also responded differently. Brightness parameter was increased in dark brown hair colored with both dyes, whereas light blond hair showed the opposite result. Regarding the breaking strength, there were no significant differences between the two kinds of tresses. Cosmetic formulations should adjust the consumer desired effects (e.g. color change) in order to present minimal drawbacks (e.g. decrease of hair brightness and strength). Thus, the study of different vehicles is important when establishing the best oxidative dye formulation.

RESUMO Objetivo: Determinar o volume médio das gotas produzidas pelos colírios lubrificantes em diferentes ângulos de inclinação e determinar o custo médio do tratamento. Métodos: Determinação do volume da gota de 3 frascos originais dos colírios lubrificantes Artelac®, Hylo Comod®, Lacrima® Plus, Systane® UL, Lacrifilm®, Hyabak®, Lacribell®, Ecofilm®, Mirugell®, Plenigell®, Fresh Tears®, Optive® e Endura® à inclinação de 90º e 45º. Determinou-se o número médio de gotas em cada frasco e foi feita avaliação farmacoeconômica dos colírios. Resultados: O volume das gotas variou de 32,2 a 64,0 µL a 45o e de 29,1 a 65,1 µL a 90o. A diferença entre as gotas em cada inclinação foi de 2 a 24% e o custo anual dos colírios de acordo com a inclinação variou de R$2,73 a R$130,73. A Duração Máxima de Tratamento (DMT) foi de 29,3 a 51,4 dias na inclinação de 45o, e de 28,8 a 48,4 dias a 90º, sendo que a diferença na DMT foi de 0,5 até 8 dias a mais ou a menos, de acordo com a marca. Conclusão: Nenhum dos colírios estudados apresentou gotas ideais para o olho humano, levando a um desperdício do produto e maior custo para o fabricante e para o consumidor. Percebemos que existe uma variação significativa no volume da gota de acordo com a inclinação do frasco, e que uma variação maior do que 10% traria impactos financeiros para o paciente.

ABSTRACT Objective: To determine the mean drop volume produced by artificial tear solutions in different inclination angles and to determine the mean cost of the treatment. Methods: The drop volume of 3 original bottles of the artificial tear solutions Artelac®, Hylo Comod®, Lacrima® Plus, Systane® UL, Lacrifilm®, Hyabak®, Lacribell®, Ecofilm®, Mirugell®, Plenigell®, Fresh Tears®, Optive® and Endura® were determined at the inclination of 90º and 45º. The mean number of drops in each bottle was determined and a pharmacoeconomic evaluation of the drops was made. Results: The drop volume ranged from 32.2 to 64.0 µL at 45º and from 29.1 to 65.1 µL at 90º. The difference between drops in each inclination varied from 2 to 24%. The annual cost was from R$2,73 to R$130,73 according to the inclination of the bottle. The Maximum Duration of Treatment (MDT) was from 29.3 to 51.4 days at 45o and from 28.8 to 48.4 days at 90º, being the difference in MDT from 0.5 to 8 more or less days depending on each brand. Conclusion: None of the collyria studied presented ideal drops for human eyes, leading to a waste of the product and higher cost for the manufacturer and the consumer. We noted that there is a significant variation in the drop volume according to the inclination of the bottle, and that a variation of over 10% would bring financial impact for the patient.