Cecropia pachystachya Trécul: a promising ingredient for skin-whitening cosmetics

Abstract Because it promotes the lightening of pigment spots, tyrosinase inhibition is one of the mechanisms of depigmenting cosmetic products. Considering the adverse effects produced by synthetic depigmenting actives, the search for new therapeutic options is desirable, and plant extracts are possible candidates for hyperpigmentation treatment. Glycolic extracts of Cecropia pachystachya Trécul are, therefore, the focus of this study. Its chemical characterization, antioxidant activity, tyrosinase inhibition, and cell viability were evaluated. Glycolic extracts were obtained by macerating the leaves of C. pachystachya in grain alcohol and glycerin or propylene glycol. Both had a similar chemical constitution, the glycerin being more efficient in concentrating phenolic compounds and flavonoids. Analyses by UHPLC-MS detected quinic acid, chlorogenic acid isomers, proanthocyanidin dimers type B and C, catechin/epicatechin, orientin/isoorientin, isoorientin 2"-O-xyloside, vitexin/isovitexin, and rutin. 5-O-caffeoylquinic acid was then quantified was then quantified, with predominance in the extract produced with propylene glycol. These extracts showed a high antioxidant capacity by the method of DPPH, ß-carotene, and nitric oxide. As for depigmenting activity, both extracts were able to inhibit tyrosinase. Cell viability assay also revealed that the extracts could safely be used in concentrations of ≤ 125 µg/mL. Thus, this study demonstrated for the first time that the glycolic extracts of C. pachystachya have promising chemical and biological characteristics for the development of a multifunctional cosmetic with antioxidant and tyrosinase-inhibition activities

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.

Critical evaluation of the off-label indication and of the risks associated to the use of multi-dose vials on the treatment of age-related macular degeneration

Age-related macular degeneration (AMD) is an ocular inflammatory diseases treated mainly by means of a bevacizumab (Avastin®) or ranibizumab (Lucentis®) intravitreal injection. Among these drugs, only ranibizumab has a specific therapeutic indication for AMD. Considering that, the off-label use on ophthalmic therapy seems to become a rule when it should be an exception. Furthermore, bevacizumab presentation consists of multi-dose vials although it does not contain preservatives in its formula. The current literature review aimed at assessing the risks for the patient related to the use of off-label indication and multi-dose vials on AMD treatment. Considering this, the proposal related to the Brazilian Public Consultation no.10, dated September 12, 2012, which proposes the Clinical Protocol and Therapeutic Guidelines for AMD treatment, was evaluated. This systematic review allowed to conclude that the bevacizumab off-label indication results in increased risks for the patient when compared to the product with specific therapeutic indication for AMD treatment (ranibizumab), especially referring to the significant raise in the adverse events. The risks for the patient related to the multi-dose vial use, referring to the microbiological stability and dose precision, were also made clear.

A degeneração macular relacionada à idade (DMRI) é uma doença ocular inflamatória tratada principalmente por injeção intravítrea de bevacizumabe (Avastin®) ou de ranibizumabe (Lucentis®). Entre os medicamentos citados, apenas o ranibizumabe tem indicação terapêutica específica para uso oftálmico. Considerando essa realidade, o uso off-label na terapia oftálmica parece constituir regra quando deveria ser exceção. Ademais, a apresentação do bevacizumabe consiste em frascos de múltipla-dose, embora esse medicamento não contenha conservante em sua fórmula. A presente revisão da literatura avaliou os riscos ao paciente relativos ao uso indicado off-label e de frascos de múltipla-dose no tratamento de DMRI. Nesse sentido, avaliou-se a proposta relativa à Consulta Pública Brasileira nº 10, de 12 de setembro de 2012, que propõe o Protocolo Clínico e Diretrizes Terapêuticas para o tratamento de DMRI. O levantamento sistemático de trabalhos científicos e de informações relevantes de banco de dados eletrônicos permitiu concluir que a indicação off-label do bevacizumabe acarreta riscos maiores ao paciente, quando comparado ao produto com indicação terapêutica específica para o tratamento de DMRI (ranibizumabe), especialmente quanto ao aumento significativo de eventos adversos. Evidenciaram-se, também, os riscos ao paciente relativos ao uso de frascos de múltipla-dose, quanto à estabilidade microbiológica e à precisão da dose.

Nanoparticulas de poli (n-butil-cianoacrilato) revestidas com N,N,N,-trimetilquitosana: desenvolvimento, caracterização e estudos de permeabilidade in vitro / N,NN-trimethylchitosan coated poly (n-butyl cyanoacrylate) nanoparticles: development, characterization and in vitro permeability

A via oral é considerada preferencial para a administração de fármacos, sobretudo no tratamento de doenças crônicas. Entretanto, princípios ativos administrados por essa via podem apresentar biodisponibilidade variável e/ou limitada. Diversos tipos de sistemas de liberação vêm sendo desenvolvidos com o objetivo de melhorar esse parâmetro, dentre os quais se destacam as nanopartículas de poli (alquil-cianoacrilato) (PACA). Pelo exposto, no presente trabalho foram desenvolvidas nanopartículas de poli(n-butilcianoacrilato) (PBCA) contendo aciclovir (ACV), revestidas por N,N,N-trimetilquitosana (TMQ), um promissor promotor de absorção. A TMQ foi sintetizada com elevado rendimento e grau de quaternização de aproximadamente 73%. As nanopartículas de PBCA foram obtidas com rendimento adequado e apresentaram características físico-químicas semelhantes às descritas na literatura. Após o revestimento, foi observado um aumento no diâmetro médio, bem com uma inversão nos valores de potencial zeta. Essas observações podem indicar a ocorrência do revestimento. A partir das análises de DSC, pôde-se comprovar a eficiência do revestimento das nanopartículas pelo derivado sintetizado, já que o comportamento das nanopartículas de PBCA-TMQ foi diferente daquele obtido para a mistura física entre os constituintes da formulação. Nessa mesma perspectiva, análises de FTIR foram conduzidas e a ocorrência do revestimento foi corroborada. Além disso, as análises morfológicas por Microscopia de Força Atômica (AFM) revelaram que as nanopartículas revestidas apresentam baixa tendência à agregação, o que pode ser um indicativo de estabilidade para a formulação desenvolvida. Em relação aos ensaios de citotoxicidade, foi evidenciado que as nanopartículas de PBCA não apresentaram toxicidade significativa frente às células Caco-2, ao passo que a formulação revestida mostrou um efeito tóxico dose-dependente influenciado pelo grau de quaternização. Além disso, as nanopartículas desenvolvidas foram capazes de diminuir, reversivelmente, a Resistência Elétrica Transepitelial (RET) da monocamada de células. A fim de quantificar o fármaco associado às nanopartículas, foi desenvolvido e validado método analítico por espectrofotometria derivada com detecção no UV. Tal método mostrou-se capaz de eliminar a interferência dos excipientes, permitindo a quantificação do ACV na formulação de nanopartículas com precisão e exatidão adequadas. Assim, a porcentagem de fármaco associado às nanoestruturas pode ser calculada, obtendo-se um valor satisfatório. De maneira semelhante, foi desenvolvido e validado método por CLAE para a quantificação do fármaco nos ensaios de permeação. A metodologia proposta mostrou-se adequada considerando-se as recomendações da RE 899/03. Por meio dos ensaios de permeabilidade em células Caco-2, foi constatado que a formulação desenvolvida aumentou em 3 vezes o valor de Permeabilidade aparente (Papp) do fármaco em estudo. Além disso, as nanopartículas revestidas foram capazes de propiciar a liberação controlada do ACV nos ensaios de liberação in vitro utilizando meios com diferentes valores de pH (1,2; 6,8 e 7,4)

The oral route is considered for the administration of drugs, especially in the treatment of chronic diseases. However, drugs administered by this route may have variable and/or limited bioavailability. Various types of delivery systems have been developed with the goal of improving this parameter, among which stand out the nanoparticles of poly (alkylcyanoacrylate) (PACA).Such nanomaterials have been coated to improve stability in the gastrointestinal tract, promote greater solubility or enhance permeation. Therefore, in this work were developed nanoparticles of poly (n-butilcianoacrilato) (PBCA) containing acyclovir (ACV), coated with N,N,N-trimethylchitosan (TMC), a promising absorption promoter. The TMC was synthesized with high-yield and approximately 73% of quaternization. The PBCA nanoparticles presented physico-chemical characteristics similar to those described in the literature. After the coating, it was observed an increase in the average diameter, and a inversion on the values of zeta potential. These observations may indicate the occurrence of coating. DSC analysis could proved the efficiency of the coating of nanoparticles, since the behavior of nanoparticles of PBCA-TMC was different from those obtained for the physical mixture between the constituents of the formulation. In this same perspective, FTIR analyses were conducted and the occurrence of coating was corroborated. In addition, morphological analyses by Atomic Force Microscopy (AFM) showed that nanoparticles coated presented low tendency to aggregate, which can be an indication of stability for the formulation developed. In relation to cytotoxicity assays, it was evidenced that the PBCA nanoparticles showed no significant toxicity against the Caco-2 cells, whereas the coated formulation showed a dose-dependent toxic effect influenced by the degree of quaternization. In addition, the nanoparticles developed were able to decrease, reversibly, Transepitelial Electric Resistance (TEER) of the monolayer. In order to quantify the drug associated with nanoparticles, was developed and validated analytical method by derivative spectrophotometry with UV detection. This method was able to eliminate the interference of excipients, allowing the quantification of ACV in the formulation of nanoparticles with appropriate precision and accuracy. Thus, the percentage of drug associated with nanostructures can be calculated, obtaining a satisfactory value. Similarly, has been developed and validated HPLC method for the quantification of drug permeation tests. The proposed methodology was appropriate considering the recommendations of the RE 899/03. Through the permeability assays in Caco-2 cells, it has been found that the formulation developed increased by 3 times the value os Apparent Permeability (Papp) of ACV. In addition, the nanoparticles were able to provide controlled release of ACV in vitro using media with different pH values (1.2; 6.8 and 7.4)