Abstract The human oral cavity is colonized by a diversity of microorganisms living harmoniously. When an imbalance occurs in this population, also called dysbiosis, opportunistic microorganisms lead to oral infections. Nystatin, a traditional antifungal, and red propolis, a resinous mixture collected by honeybees from plant source, can be used to control oral infections. Using β-cyclodextrin (βCD) inclusion complexes with nystatin and red propolis may improve the solubility, stability and antimicrobial activity of these substances, making it possible to include these complexes in pharmaceutical formulations. This study aimed to obtain these inclusion complexes by solubilization and characterize and evaluate their antimicrobial activity against microorganisms from the oral cavity. The inclusion complexes showed loss of crystallinity and the infrared spectra showed interactions between the substances. The content of total polyphenol ranged from 4.32-4.62 mg/g, while the content of flavonoids was between 3.05-3.83 mg/g. The red propolis (Prop):βCD(1:1 and 2:1) complexes were the most active against S.aureus, S.epidermidis, S.mutans and C.albicans with Minimum Inhibitory Concentration (MIC) ranging between 32-256 µg/mL. The inclusion complex of nystatin (Nys):βCD(1:1) effectively inhibited C.albicans growth (MIC=4µg/mL). Interestingly, the association between Nys:βCD(1:1) and Prop:βCD(1:1 or 2:1) showed a synergic effect, improving antifungal activity when compared to red propolis complex alone.

Atualmente, antioxidantes são usados como excipientes eficientes, que retardam ou inibem o processo de oxidação de moléculas. Excipientes são frequentemente associados a efeitos adversos. Estudos de estabilidade podem ajudar na busca por possíveis soluções para minimizar ou retardar os processos de degradação. A habilidade de prever as reações de oxidação em diferentes fármacos é importante. O estudo foi conduzido com o objetivo de avaliar o uso racional de hidroxianisol butilado (BHA), hidroxitolueno butilado (BHT), metabissulfito sódico (SMB), galato de propila (PG) e cisteína (CYS) em formulações de comprimidos de sinvastatina e cetoconazol. Eles foram avaliados por parâmetros de estabilidade e pela relação entre a eficiência dos antioxidantes e a estrutura química do fármaco. Os resultados foram comparados com testes de DPPH e simulações em computador. BHT foi mais eficiente com relação a estabilidade da sinvastatina e às concentrações mais eficientes para manutenção de estabilidade foram 0,5 e 0,1%. Com relação ao cetoconazol, SMB foi mais eficiente em manter o conteúdo e o perfil de dissolução. A avaliação por DPPH mostrou que o maior percentual de redução de absorção foi observado para PG, enquanto que SMB mostrou ser mais eficiente e consumir menos DPPH. A mesma tendência foi observada com menos eficiência em todos os outros antioxidantes lipofílicos como o BHT e BHA. Os resultados do estudo de modelagem molecular demonstraram que as propriedades eletrônicas obtidas podem ser correlacionadas com a atividade antioxidante em solução, sendo útil para o desenvolvimento racional de formulações farmacêuticas líquidas, mas não para formulações sólidas orais. Este estudo demonstrou a importância de considerar parâmetros de estabilidade e modelagem molecular para elucidar os fenômenos químicos envolvidos na atividade antioxidante, sendo úteis para o uso racional de antioxidantes no desenvolvimento de formulações farmacêuticas.

Antioxidants are currently used as efficient excipients that delay or inhibit the oxidation process of molecules. Excipients are often associated with adverse reactions. Stability studies can guide the search for solutions that minimize or delay the processes of degradation. The ability to predict oxidation reactions in different drugs is important. Methods: This study was conducted to assess the rational use of butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), sodium metabisulfite (SMB), propyl gallate (PG) and cysteine (CYS) in tablet formulations of simvastatin and ketoconazole. These antioxidants were evaluated according to stability parameters and the relationship between efficiency of the antioxidant and chemical structure of the drugs. Results were compared with DPPH tests and computational simulations. BHT was most efficient regarding simvastatin stability, and the most effective BHT concentrations for maintaining stability were 0.5 and 0.1%. In relation to ketoconazole, SMB was most efficient for maintaining content and dissolution profile. The evaluation by DPPH showed that the largest percentage of absorbance reduction was observed for PG, while SMB proved most efficient and had lower consumption of DPPH. The same pattern was observed, albeit with lower efficiency, for the other lipophilic antioxidants such as BHT and BHA. The results of the molecular modeling study demonstrated that electronic properties obtained were correlated with antioxidant activity in solution, being useful for the rational development of liquid pharmaceutical formulations but not for solid oral formulations. This study demonstrated the importance of considering stability parameters and molecular modeling to elucidate the chemical phenomena involved in antioxidant activity, being useful for the rational use of antioxidants in the development of pharmaceutical formulations.

A reversed-phase HPLC method was developed and validated to separate and simultaneously quantify the association of betamethasone sodium phosphate (BP) and betamethasone dipropionate (BD) in injectable suspensions. Chromatographic conditions were ternary gradient elution at 1.6 mL/min on a C18 column with 254 nm. The linearity of the method was established in the range 120 to 280 mg/mL BD, and 48 to 112 mg/mL BP. The RSD of intermediate precision of the method was <1% and recoveries were 99-101% for both drugs. The method proved selective, linear, precise, accurate and robust for quantifying BP and BD in commercial injectable suspensions.

Celecoxib (CB) and lumiracoxib (LM) are potent COX-2 inhibitors widely marketed for the treatment of rheumatoid arthritis and osteoarthritis. Nevertheless, it is difficult to obtain because it are protected under patents. The aim of this work was to develop an extraction method of drugs, CB and LM, in order to obtain the drug with a purity degree appropriated for use in research projects. The developed method showed to be effective of both drugs, becoming interesting due to its low cost, easy and speed of execution, application to different dosage forms (capsules and tablets) and drugs with different physicochemical properties.