RESUMEN
BACKGROUND: Efficacy of melatonin in treating sleep disorders has been demonstrated in numerous studies. Being with short half-life, melatonin needs to be formulated in extended-release tablets to prevent the fast drop of its plasma concentration. However, an attempt to mimic melatonin natural plasma levels during night time is challenging. METHODS: In this work, Artificial Neural Networks (ANNs) were used to optimize melatonin release from hydrophilic polymer matrices. Twenty-seven different tablet formulations with different amounts of hydroxypropyl methylcellulose, xanthan gum and Carbopol®974P NF were prepared and subjected to drug release studies. Using dissolution test data as inputs for ANN designed by Visual Basic programming language, the ideal number of neurons in the hidden layer was determined trial and error methodology to guarantee the best performance of constructed ANN. RESULTS: Results showed that the ANN with nine neurons in the hidden layer had the best results. ANN was examined to check its predictability and then used to determine the best formula that can mimic the release of melatonin from a marketed brand using similarity fit factor. CONCLUSION: This work shows the possibility of using ANN to optimize the composition of prolonged-release melatonin tablets having dissolution profile desired.
Asunto(s)
Preparaciones de Acción Retardada , Melatonina/química , Redes Neurales de la Computación , Química Farmacéutica , Melatonina/administración & dosificación , Solubilidad , ComprimidosRESUMEN
This study was conducted to assess cholestasis in human fascioliasis. Twenty five patients, passing Fasciola eggs, were compared to twenty age- and sex-matched healthy controls. All were subjected to thorough clinical examination, stool analysis, complete blood picture, liver function tests (AST, ALT, SAP, GGT and total serum bilirubin). Autoimmune and viral hepatitis (HCV & HBV) were excluded. All cases were subjected to radiological examinations (chest x-ray and abdominal ultrasonography). The study revealed significant elevation of liver enzymes in the patients compared to the controls (p < 0.001). Calcular and non-calcular cholecystitis were common findings among patients (32% and 24% respectively). Ascites (4%) and dilated intra-hepatic biliary radicals (32%) were encountered; pleural effusion was detected by chest x-ray in 20% of cases. So, fascioliasis should be considered in the diagnosis of cholestasis in Fasciola endemic areas.