Desenvolvimento e validação de método por cromatografia líquida de alta eficiência para determinação simultânea das impurezas timina e timidina na matéria-prima estavudina

Silva, Gisele Rodrigues da; Condessa, Felipe Antonacci; Pianetti, Gérson Antônio; Nunan, Elzíria de Aguiar; Campos, Lígia Maria Moreira de

doi:10.1590/s0100-40422008000700016

Cited by 4 publications

(3 citation statements)

References 13 publications

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“…This product is mainly formed after hydrolytic and oxidative processes (Silva et al, 2008). Table II shows solubility results (in mg mL -1 ) and dose:solubility ratio (in mL) for antiretroviral drugs and the Figure 1 represents average solubility of 3TC, d4T and AZT, respectively.…”

Section: Equilibrium Solubility Methods (Shake-flask)mentioning

confidence: 99%

Equilibrium solubility versus intrinsic dissolution: characterization of lamivudine, stavudine and zidovudine for BCS classification

Dezani

Pereira

Caffaro

et al. 2013

Braz. J. Pharm. Sci.

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Solubility and dissolution rate of drugs are of major importance in pre-formulation studies of pharmaceutical dosage forms. The solubility improvement allows the drugs to be potential biowaiver candidates and may be a good way to develop more dose-efficient formulations. Solubility behaviour of lamivudine, stavudine and zidovudine in individual solvents (under pH range of 1.2 to 7.5) was studied by equilibrium solubility and intrinsic dissolution methods. In solubility study by equilibrium method (shake-flask technique), known amounts of drug were added in each media until to reach saturation and the mixture was subjected to agitation of 150 rpm for 72 hours at 37 °C. In intrinsic dissolution test, known amount of each drug was compressed in the matrix of Wood's apparatus and subjected to dissolution in each media with agitation of 50 rpm at 37 °C. In solubility by equilibrium method, lamivudine and zidovudine can be considered as highly soluble drugs. Although stavudine present high solubility in pH 4.5, 6.8, 7.5 and water, the solubility determination in pH 1.2 was not possible due stability problems. Regarding to intrinsic dissolution, lamivudine and stavudine present high speed of dissolution. Considering a boundary value presented by Yu and colleagues (2004), all drugs studied present high solubility characteristics in intrinsic dissolution method. Based on the obtained results, intrinsic dissolution seems to be superior for solubility studies as an alternative method for biopharmaceutical classification purposes.Uniterms: Drugs/solubility. Drugs/dissolution rate. Intrinsic dissolution/method/biopharmaceutical classification. Biopharmaceutical Classification System.A solubilidade e a taxa de dissolução de fármacos são de grande importância em estudos de pré-formulação de formas farmacêuticas. A melhora na solubilidade permite que os fármacos sejam candidatos potenciais à bioisenção, podendo ser uma boa maneira para desenvolver formulações dose-eficientes. O comportamento de solubilidade da lamivudina, estavudina e zidovudina em solventes individuais (sob faixa de pH 1,2 a 7,5) foi estudado pelos métodos de solubilidade em equilíbrio e dissolução intrínseca. No estudo de solubilidade pelo método do equilíbrio (método de agitação de frascos), conhecidas quantidades do fármaco foram adicionadas em cada meio até atingirem a saturação e a mistura foi submetida à agitação de 150 rpm por 72 horas a 37 °C. No ensaio de dissolução intrínseca, conhecida quantidade de cada fármaco foi comprimida na matriz do aparato de Wood e submetida à dissolução em cada meio com agitação de 50 rpm a 37 °C. No método de solubilidade em equilíbrio, a lamivudina e a zidovudina podem ser consideradas como fármacos altamente solúveis. Embora a estavudina apresente alta solubilidade nos meios pH 4,5, 6,8, 7,5 e água, a determinação da solubilidade em pH 1,2 não foi possível devido a problemas de estabilidade. Com relação à dissolução intrínseca, a lamivudina e a estavudina apresentaram alta velocidade de dissolução. Considerando o valor ...

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Section: Equilibrium Solubility Methods (Shake-flask)mentioning

confidence: 99%

Equilibrium solubility versus intrinsic dissolution: characterization of lamivudine, stavudine and zidovudine for BCS classification

Dezani

Pereira

Caffaro

et al. 2013

Braz. J. Pharm. Sci.

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“…34,35 Routinely, the analysis of lowconcentration thymine is conducted by high-performance liquid chromatography (HPLC) but it involves high reagent cost and is time-consuming. 36 We present Fe 3+ −IP 6 @AgNPsbased SERS method as a fast and sensitive tool might be developed for the detection of low-concentration thymine in this work.…”

Section: Introductionmentioning

confidence: 99%

“…Thymine as one of the four nucleic acid bases plays important role in genetic expression and replications. In addition, the high photoreactivity of thymine exhibits the adsorption of ultraviolet light leading to the creation of a cyclobutane dimer. , Routinely, the analysis of low-concentration thymine is conducted by high-performance liquid chromatography (HPLC) but it involves high reagent cost and is time-consuming . We present Fe 3+ –IP 6 @AgNPs-based SERS method as a fast and sensitive tool might be developed for the detection of low-concentration thymine in this work.…”

Section: Introductionmentioning

confidence: 99%

Improving SERS Activity of Inositol Hexaphosphate Capped Silver Nanoparticles: Fe³⁺ as a Switcher

Guo

et al. 2014

Inorg. Chem.

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Inositol hexaphosphate (IP6) capped silver nanoparticles (IP6@AgNPs) were fabricated as surface-enhanced Raman scattering (SERS) active substrates. SERS activity of IP6@AgNPs could be further improved via adding due amounts of Fe(3+) to form Fe(3+)-IP6@AgNPs. The mechanism of Fe(3+)-induced SERS improvement of IP6@AgNPs can be attributed to the strong interaction of IP6 and Fe(3+), which leads to controllable adjustment of the gap among neighboring nanoparticles to produce "hot spots". The above mechanism was confirmed with ultraviolet-visible (UV-vis) spectroscopy, transmission electron microscope (TEM), dynamic light scattering (DLS), Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Such Fe(3+)-IP6@AgNPs-based SERS system was used to detect Rhodamine 6G (R6G) down to the trace level of 10(-10) mol L(-1). Besides, New Fuchsin (NF) was also used as a Raman probe to calculate the enhancement factor (EF) of IP6@AgNPs without and with Fe(3+). The SERS activity of IP6@AgNPs happened extreme decrease after one-year storage and could be recovered to great extent aided by the addition of Fe(3+). The Fe(3+) optimized IP6@AgNPs system could be applied to detect thymine at trace level by SERS.

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Quantitative analysis of thymine with surface-enhanced Raman spectroscopy and partial least squares (PLS) regression

Zhang

Wei

et al. 2010

Anal Bioanal Chem

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Silver sol surface-enhanced Raman spectroscopy (SERS) was considered as a technique in the quantitative analysis of low-concentration thymine. Because of the poor stability and reproducibility of SERS signal, a polymer of polyacrylic acid sodium was selected as a stable medium to add into silver sol in order to obtain a surface-enhanced Raman spectroscopy signal. Assignments of Raman shift for solid thymine, SERS of thymine, and SERS of thymine containing stable medium were given. The comparison of Raman peaks between them showed that the addition of stable medium had a little influence on the SERS of thymine and is suitable for the quantitative analysis of low-concentration thymine.

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Desenvolvimento e validação de método por cromatografia líquida de alta eficiência para determinação simultânea das impurezas timina e timidina na matéria-prima estavudina

Cited by 4 publications

References 13 publications

Equilibrium solubility versus intrinsic dissolution: characterization of lamivudine, stavudine and zidovudine for BCS classification

Equilibrium solubility versus intrinsic dissolution: characterization of lamivudine, stavudine and zidovudine for BCS classification

Improving SERS Activity of Inositol Hexaphosphate Capped Silver Nanoparticles: Fe³⁺ as a Switcher

Quantitative analysis of thymine with surface-enhanced Raman spectroscopy and partial least squares (PLS) regression

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Desenvolvimento e validação de método por cromatografia líquida de alta eficiência para determinação simultânea das impurezas timina e timidina na matéria-prima estavudina

Cited by 4 publications

References 13 publications

Equilibrium solubility versus intrinsic dissolution: characterization of lamivudine, stavudine and zidovudine for BCS classification

Equilibrium solubility versus intrinsic dissolution: characterization of lamivudine, stavudine and zidovudine for BCS classification

Improving SERS Activity of Inositol Hexaphosphate Capped Silver Nanoparticles: Fe3+ as a Switcher

Quantitative analysis of thymine with surface-enhanced Raman spectroscopy and partial least squares (PLS) regression

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Product

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Improving SERS Activity of Inositol Hexaphosphate Capped Silver Nanoparticles: Fe³⁺ as a Switcher