Simultaneous determination of abamectin homologs H 2 B 1a and H 2 B 1b in gel formulation by high performance liquid chromatography

ABSTRACT Abamectin is a drug with antiparasitic properties used in several pharmaceutical formulations. The objective of this research was to develop and validate a high performance liquid chromatographic (HPLC) method for quantification of the two abamectin homologs (H2B1a and H2B1b) in gel formulation. This HPLC method was validated using a LichroCart(r) 100 RP-18 (125 x 4 mm, 5 µm) column. The mobile phase contained of acetonitrile and water (95:5 v/v) with 1% acetic acid. The flow rate was 1.0 mL min-1 and UV detection was performed at 245 nm. Mobile phase solutions were prepared containing a nominal concentration 185.2 µg mL-1 H2B1a and 9.6 µg mL-1 H2B1b. The method displayed good linearity in the concentration range of 148.1 - 222.3 µg mL-1 and 7.7 - 11.5 µg mL-1, for H2B1a and H2B1b, respectively, with a correlation coefficient of (r)> 0.99 for both compounds, calculated by the least mean squares method. Detection limits (DLs) were 2.8 µg mL-1 and 1.2 µg mL-1 and quantitation limits (QLs) were 8.6 µg mL-1 and 3.8 µg mL-1, for H2B1a and H2B1b, respectively. The method is simple, economical and efficient for the quantitative determination of abamectin H2B1a and H2B1b homologs in pharmaceutical preparations.

Reverse phase high-performance liquid chromatography for quantification of hydroxymethylnitrofurazone in polymeric nanoparticles

Hydroxymethylnitrofurazone (NFOH) is a new compound with potential leishmanicidal and trypanocidal activity. Despite its effectiveness, the formulators have to overcome its poor aqueous solubility. Recently, polymeric nano-scale drug delivery systems have proposed for the treatment of neglected diseases. As several studies have confirmed the advantages of such formulations, and this approach provides new analytical challenges, including the need to detect trace amounts of the drug. A suitable method was developed and validated for NFOH determination bound to poly (n-butylcyanoacrylate) (PBCA) nanoparticles. The chromatographic separation was achieved using a C18 column maintained at 25 ºC and an isocratic mobile phase consisting of water and acetonitrile: 80:20 (v/v) at a flow rate of 1.2 mL min-1 and UV-detection at 265 nm. Investigated validation parameters included selectivity, linearity, accuracy, precision and robustness (changes in column temperature, mobile phase composition and flow). The method was specific, the peak of NFOH had no interference with any nanoparticle excipients and no co-elution with main degradation product (nitrofurazone). Linearity was over the range of 0.94 13.11 μg mL-1 (r2=0.999). The method was accurate and precise, recovery of 100.7%, RSD of 0.4%; intra-day and inter-day RSD range 9.98-9.99 μg mL-1 and 0.3% to 0.5%, respectively. Robustness confirmed that method could resist the applied changes. Application of the optimized method revealed an encapsulation efficiency of 64.4% (n=3). Therefore, the method was successfully developed and validated for the determination of the encapsulation efficiency of NFOH-PBCA nanoparticles.

Hidroximetilnitrofural (NFOH) é um novo composto que possui atividade leishmanicida e tripanomicida potencial. Um método apropriado foi desenvolvido e validado para a determinação de NFOH em nanopartículas de poli(n-butil cianoacrilato) (PBCA). A separação cromatográfica foi obtida usando uma coluna C18 (5 µm de tamanho de partícula, 4,6 mm de diâmetro e 150 mm de comprimento), mantida a 25 °C, fase móvel composta de água e acetonitrila 80:20 (v/v), fluxo de 1,2 mL min- 1 e detecção por UV a 265 nm. Investigaram-se os seguintes parâmetros de validação: seletividade, linearidade, exatidão, precisão e robustez (mudanças na temperatura de coluna, proporção da fase móvel e fluxo). O método mostrou-se específico, o pico de NFOH não apresentou interferência dos picos provenientes dos excipientes das nanopartículas e separado do principal produto de degradação (nitrofural). A linearidade foi obtida na faixa de 0,94-13,11 μg mL- 1 (r2=0,999). O método mostrou exatidão (recuperação de 100,7%, DPR de 0,4 %) e precisão (intra-dia e inter-dia, 9,98-9,99 μg mL- 1 e DPR 0,3% a 0,5%, respectivamente). A robustez provou que o método pode resistir às mudanças propostas. Aplicação do método otimizado revelou eficiência de encapsulação de 64,4% (n=3). Portanto, o método foi desenvolvido e validado com sucesso para a determinação da eficiência de encapsulação de nanopartículas de NFOH-PBCA.

Validation of high-performance liquid chromatographic method for analysis of fluconazole in microemulsions and liquid crystals

In recent decades, there has been a significant increase in the incidence of fungal diseases. Certain fungal diseases cause cutaneous lesions and in the usual treatment, generally administred orally, the drug reaches the site of action with difficulty and its concentration is too low. An approach much explored in recent years is the development of nanotechnology-based drug delivery systems, and microemulsions (ME) and liquid crystals (LC) are promising. ME and LC were developed with oleic acid or copaiba oil as the oil phase, propoxyl (5OP) ethoxyl (20 OE) cetyl alcohol as surfactant and water. An analytical method to assess the incorporation of fluconazole (FLU) in the systems under study was validated according to guidelines of the International Conference on Harmonization (ICH) guidelines and the Brazilian Food, Drug and Sanitation Agency (ANVISA). The method was conducted on a C18-RP column (250 × 4.6 mm i.d.), maintained at room temperature. The mobile phase consisted of acetonitrile and water (50:50, v/v), run at a flow rate of 1.0mL/min and using ultraviolet detection at 210nm. The chromatographic separation was obtained with a retention time of 6.3min, and was linear in the range of 20-400 µg/mL (r2=0.9999). The specificity showed no interference of the excipients. The accuracy was 100.76%. The limits of detection and quantitation were 0.057 and 0.172 µg.mL-1, respectively. Moreover, method validation demonstrated satisfactory results for precision and robustness. The proposed method was applied for the analysis of the incorporation of FLU in ME and LC, contributing to improve the quality control and to assure the therapeutic efficacy.

Nas últimas décadas, houve aumento significativo na incidência de doenças fúngicas. Certas doenças fúngicas provocam lesões cutâneas, sendo que no tratamento usual, geralmente administrado por via oral, o medicamento chega ao local de ação com dificuldade, em concentração muito baixa. Uma abordagem muito explorada nos últimos anos é o desenvolvimento de sistemas de administração de fármacos baseados em nanotecnologia, como as microemulsões (ME) e cristais líquidos (LC). ME e LC foram desenvolvidos com o ácido oleico ou óleo de copaíba como fase oleosa, álcool cetílico propoxilado (5 OP) e etoxilado (20 OE) como tensoativo e água. Método analítico para avaliar a incorporação de fluconazol (FLU) nos sistemas em estudo foi validado de acordo com as diretrizes da Conferência Internacional de Harmonização (ICH) e Agência Nacional de Vigilância Sanitária (ANVISA). O método foi desenvolvido empregando coluna C18-RP (250 x 4,6 mm id), mantida à temperatura ambiente. A fase móvel consistiu de acetonitrila e água (50:50, v/v), executado a uma taxa de fluxo de 1,0 mL/min e com detecção ultravioleta a 210 nm. A separação cromatográfica foi obtida com o tempo de retenção de 6,3min, e mostrou-se linear no intervalo de 20-400 µg/mL (r2=0,9999). Pelo estudo de especificidade, observou-se não interferência dos excipientes. A precisão foi 100,76%. Os limites de detecção e de quantificação foram 0,057 e 0,172 µg.mL-1, respectivamente. Além disso, a validação do método demonstrou resultados satisfatórios para a precisão e robustez. O método proposto foi aplicado para a análise da incorporação do FLU em ME e cristais líquidos, contribuindo para aumentar o controle de qualidade e garantir a eficácia terapêutica.