Development of derivative spectrophotometric method for simultaneous determination of pyrazinamide and rifampicin in cubosome formulation

The ultraviolet spectrophotometry analysis for quantitative assay of drugs is a method accurate, sensitive, selective and reproductive with the advantage of being a simple and less expensive method. In this study, a derivative ultraviolet spectrophotometric method was developed for simultaneous determination of pyrazinamide (PYZ) and rifampicin (RIF). The spectrophotometric method was evaluated according to validation guidelines for specificity, linearity, limits of detection and quantification, precision, accuracy and robustness. The first-derivative spectra were obtained and by the zerocrossing point, the wavelength 247 nm and 365 nm were selected for PYZ and RIF quantification, respectively. No interference from cubosome excipients was detected in the proposed method. The results demonstrated linearity in a range of 4.0 – 12.0 µg/mL with an adequate correlation coefficient for both drugs. The intra and inter-day precision results (RSD < 5%) indicated the reproducibility of the method. The accuracy data showed satisfactory results (RSD < 5%) from recovery test. In addition, the robustness results showed that the PYZ and RIF content were unaffected by the solvent alteration of methanol to methanol:water (99:1, v/v). The derivative ultraviolet spectrophotometric method proved to be an excellent strategy for simultaneous determination of PYZ and RIF

Nanocarreador, composição, processo de obtenção e uso do mesmo para a preparação de uma composição farmacêutica, nutracêutica, cosmética ou com aplicação em agropecuária

Universidade Federal do Rio Grande do SulFarmáciaQuímicaDepositad

Nanoemulsion containing kojic dipalmitate and rosehip oil : a promising formulation to treat melasma

Melasma is a hard-to-treat hyperpigmentation disorder. Combined incorporation of kojic dipalmitate (KDP), the esterified form of kojic acid, and rosehip oil, an oil with antioxidant and skin-regenerating properties, into nanocarrier systems appears to be a suitable strategy to develop high-performance formulations. A high-energy method (Ultra-Turrax®) was used to develop nanoemulsions containing up to 2 mg/mL KDP, 5% rosehip oil, and 7.5% surfactant. Formulations were characterized regarding droplet size, size distribution, pH, density, morphology, KDP content, incorporation efficiency, and stability under different temperature conditions. A scale-up study was conducted. Skin permeation, antioxidant potential, and tyrosinase inhibitory activity were assessed in vitro. Cell viability studies were also performed. Results showed that nanoemulsions containing 1 and 2 mg/mL KDP had incorporation efficiencies greater than 95%, droplet size smaller than 130 nm, suitable size distribution, zeta potential of approximately 10 mV, and good stability over 30 days of refrigerated storage. The nanoemulsion containing 1 mg/mL KDP was chosen for further evaluation because it had lower nanocrystal formation, greater scale-up feasibility and allowed KDP permeation up to the epidermis similarly than observed for 2 mg/mL KDP. This formulation (1 mg/mL KDP) showed antioxidant and depigmenting efficacy, close to that of 1 mM ascorbic acid. No cytotoxicity was observed in formulations concentrations ranging from 0.06% to 1%

New trends to combat Candida biofilm in dental prosthetics

Apesar de a espécie Candida albicans ser efetivamente o microrganismo mais frequentemente associado a estomatite protética, as espécies de Candida não albicans já foram isoladas nas superfícies de dentaduras e da mucosa oral de indivíduos com essa lesão eritematosa. A virulência das espécies de Candida e a capacidade de adesão a polímeros acrílicos são condições prévias para a colonização e o desenvolvimento de biofilmes em superfícies de dentaduras. Estudos recentes focam na tentativa de modificação das resinas acrílicas para diminuir a adesão de cepas patogênicas e formadoras de biofilme do gênero Candida spp. Dentro desse aspecto, esta revisão sistematiza o atual panorama epidemiológico da estomatite protética associada ao uso de próteses dentárias, bem como as atuais e novas opções de combate ao biofilme fúngico especializado na adesão desse tipo de biomaterial.Although the Candida albicans species is effectively the microorganism most frequently associated with prosthetic stomatitis, Candida non-albicans species have already been isolated from the denture and oral mucosal surfaces of individuals with this erythematous lesion. The virulence of Candida species and the ability to adhesion to acrylic polymers are preconditions for the colonization and development of biofilms on denture surfaces. Recent studies focus on the attempt to modify the acrylic resins to reduce the adhesion of pathogenic and biofilm forming strains of the genus Candida spp. In this aspect, this review systematizes the current epidemiological panorama of prosthetic stomatitis associated with the use of dental prostheses, as well as new options for combating the fungal biofilm specialized in the adhesion of this type of biomaterial

Development of a clioquinol nanocarrier as a new, promising option for the treatment of dermatomycosis

Dermatomycosis is a common fungal infection, and its treatment is limited by few antifungal agents. Clioquinol (CQ) is an antiparasitic agent that has been studied for new uses, such as antifungal and antiviral applications. CQ was incorporated into a lipid-based nanocarrier as a new, promising option for dermatomycosis. This study aimed to develop a CQ-loaded lipid-based nanocarrier for cutaneous application and to evaluate its antifungal activity. CQ-loaded nanoformulation (LBN-CQ) was developed using the ultrasonication method, and the particle size, polydispersity index (PDI), pH, zeta potential, and drug content were monitored for 45 days. To evaluate antifungal activity, broth microdilution and a time-kill assay were performed. LBN-CQ presented a particle size of 91 3 nm and PDI of 0.102 0.009. The zeta potential and pH values were 9.7 2.0 mV and 6.0 0.1, respectively. The drug content was 96.4 2.3%, and the encapsulation efficiency was 98.4%. LBN-CQ was able to reduce the minimum inhibitory concentration (MIC) in a 2-fold or 4-fold manner in most of the tested strains. Additionally, LBN-CQ presented stable fungistatic action that was not concentration- or time-dependent. In conclusion, the developed CQ-loaded nanocarrier is a promising treatment for skin fungal infections and a promising candidate for future randomized clinical trials

Lamivudine and zidovudine-loaded nanostructures : green chemistry preparation for pediatric oral administration

Here, we report on the development of lipid-based nanostructures containing zidovudine (1 mg/mL) and lamivudine (0.5 mg/mL) for oral administration in the pediatric population, eliminating the use of organic solvents, which is in accordance with green chemistry principles. The formulations were obtained by ultrasonication using monoolein (MN) or phytantriol (PN), which presented narrow size distributions with similar mean particle sizes (~150 nm) determined by laser diffraction. The zeta potential and the pH values of the formulations were around 4.0 mV and 6.0, respectively. MN presented a slightly higher incorporation rate compared to PN. Nanoemulsions were obtained when using monoolein, while cubosomes were obtained when using phytantriol, as confirmed by Small-Angle X-ray Scattering. The formulations enabled drug release control and protection against acid degradation. The drug incorporation was effective and the analyses using an electronic tongue indicated a difference in palatability between the nanotechnological samples in comparison with the drug solutions. In conclusion, PN was considered to have the strongest potential as a novel oral formulation for pediatric HIV treatment