<b>Desenvolvimento e validação de método analítico para quantificação de diclofenaco de dietilamônio em pele humana por cromatografia líquida de alta eficiência</b>

Foi desenvolvido e validado neste estudo um método analítico para quantificação de diclofenaco de dietilamônio em pele humana por cromatografia líquida de alta eficiência, segundo a Resolução 899/2003 da Agência Nacional de Vigilância Sanitária (ANVISA). Empregou-se cromatografia em fase reversa com coluna C18 150 x 4,6 mm, 5 µm Shimpack®, à temperatura de 40 ºC e fase móvel, constituída por mistura de acetonitrila e tampão fosfato de sódio 20 mM pH 3,0 (70:30, v/v) com fluxo de 1,2 mL min-1. Os analitos foram detectados por UV a 280 nm e o método foi especifico, preciso, exato, robusto e linear no intervalo de 0,05 a 20 µg mL-1 (R2 = 0,998), mostrando que pode ser utilizado em estudos de penetração cutânea in vitro tendo como modelo de membrana a pele humana. <i>Palavras-chave</i>: Diclofenaco dietilamônio. Retenção cutânea. Validação. <b>ABSTRACT</b> <i>Development and validation of an analytical method for quantitation of diclofenac diethylamine in human skin by high performance liquid chromatography</i> An analytical method has been developed and validated for the quantitation of diclofenac diethylamine (DDA) in human skin by high performance liquid chromatography (HPLC), in accordance with Regulation 899/2003 of the National Sanitary Surveillance Agency (ANVISA). The HPLC column was a reversed-phase Shimpack® C18, with a 5 µm particle bed, measuring 150 x 4.6 mm i.d., eluted isocratically at 40C with 20 mM sodium phosphate buffer (pH 3.0):acetonitrile (30:70, v/v), the mobile phase flowing at 1.2 mL min-1. Analytes were measured by a UV detector set at 280 nm. The results revealed that the method was specific, precise, accurate, robust and linear (R2=0.998) in the range from 0.05 to 20 µg mL-1. Therefore, it can safely be used to assess DDA in vitro penetration of human skin in kinetic studies. <i>Keywords</i>: Diclofenac diethylamine. Human skin retention. Validation

BMP6 and VDR gene polymorphisms are associated with osteonecrosis in a sickle cell anaemia cohort

The occurrence and severity of osteonecrosis in sickle cell anaemia (SCA) vary due to risk factors, including genetic modifiers. Bone morphogenetic proteins (BMPs), particularly BMP6, and the vitamin D receptor (VDR) play key roles in cartilage and bone metabolism, making them potential contributors to orthopaedic outcomes in SCA. Here, we evaluated the association of polymorphisms in BMP6 (rs3812163, rs270393 and rs449853) and VDR (FokI rs2228570 and Cdx2 rs11568820) genes with osteonecrosis risk in a Brazilian SCA cohort. A total of 177 unrelated SCA patients were selected. The AA genotype of BMP6 rs3812163 was independently associated with a lower osteonecrosis risk (p = 0.015; odds ratio (OR): 0.38; 95% confidence interval (CI): 0.18–0.83) and with the long-term cumulative incidence of osteonecrosis (p = 0.029; hazard ratio: 0.56, 95% CI: 0.34–0.94). The VDR rs2228570 TT genotype was independently associated with a lower osteonecrosis risk (p = 0.039; OR: 0.14; 95% CI: 0.02–0.90). In summary, our results provide evidence that BMP6 rs3812163 and the VDR rs2228570 might be implicated in osteonecrosis pathophysiology in SCA and might help identify individuals at high risk.</p