ABSTRACT A simple high performance thin layer chromatography (HPTLC) has been developed and validated for determination of sunitinib malate and possible impurities. The samples were applied in forms of bands on an aluminum TLC plate pre-coated with silica gel and were separated using dichloromethane: methanol: toluene: ammonia solution as the mobile phase. Sunitinib malate was thoroughly separated from impurities including E-isomer, sunitinib N-oxide and impurity B with a retention factor (RF) of 0.35±0.02. Quantitative analysis of sunitinib was carried out using a mobile phase consisting of dichloromethane:methanol:ammonia solution, RF value was 0.53±0.02 for Z isomer. Detection was performed densitometrically in absorbance mode at 430 nm. This method was found to produce sharp, symmetrical, and well resolved peaks. Linear relationship with the coefficients of determination > 0.99 was achieved over the concentration range of 27.34 to 437.5 ng/spot. This method provides robust, replicable and accurate results with acceptable sensitivity.

resumo Nanoparticulas lipídicas sólidas (NLSs) são sistemas coloidais de liberação interessantes, uma vez que reúnem todas as vantagens de nanopartículas lipídicas e poliméricas. A liofilização é um processo amplamente utilizado para melhorar a estabilidade das NLSs e os crioprotetores têm sido usados para diminuir a agregação destas durante esse processo. Neste estudo, a ampicilina foi escolhida para ser encapsulada em um carreador de colesterol de escala nanométrica. Para manter a estabilidade das NLSs, a liofilização foi realizada utilizando-se manitol. O tamanho de partícula, o perfil de liberação do fármaco e os efeitos antibacterianos foram estudados após a liofilização em comparação com a NLSs primária. De acordo com os resultados, as preparações que contêm 5% de manitol mostraram o menor aumento do tamanho de partícula. Os resultados de tamanhos médio foram de 150 e 187 nm antes e depois da liofilização, respectivamente. O perfil de liberação prolongada, bem como o efeito antimicrobiano da ampicilina NLSs não foram alterados após a liofilização. A análise por DSC evidenciou provável interação entre a ampicilina e o colesterol.

abstract Solid lipid nanoparticles (SLNs) are interesting colloidal drug-delivery systems, since they have all the advantages of the lipid and polymeric nanoparticles. Freeze-drying is a widely used process for improving the stability of SLNs. Cryoprotectants have been used to decrease SLN aggregations during freeze-drying. In this study Ampicillin was chosen to be loaded in a cholesterol carrier with nano size range. To support the stability of SLNs, freeze-drying was done using mannitol. Particle size, drug release profile and antibacterial effects were studied after freeze-drying in comparison with primary SLNs. Preparations with 5% mannitol showed the least particle size enlargement. The average particle size was 150 and 187 nm before and after freeze-drying, respectively. Freeze-drying did not affect the release profile of drug loaded nanopartilces. Also our study showed that lyophilization did not change the antimicrobial effect of ampicillin SLNs. DSC analysis showed probability of chemical interaction between ampicillin and cholesterol.