Natural naphthoquinones such as lapachol (Lp) have demonstrated promising biological activities. However, these quinones present low systemic biodisponibility due to its poor aqueous solubility. To overcome this problem, nanoemulsions (NE) formed by oily core are able to incorporate hydrophobic molecules thus enabling them to be dispersed into an aqueous phase. The present study reports the development, characterization, and physical stability of NE containing lapachol. NE formulations (F1, F2, F3, F4, and F2-Lp) were prepared using emulsion phase inversion (EPI) method and characterized in relation to droplet size, size distribution (PDI), zeta potential, and physical stability. The formulation chosen to incorporate lapachol (F2-Lp) showed droplet size in nanometric scale with homogeneous size distribution (PDI < 0.2) and negative zeta potential (about −30 mV). In addition, good physical stability of F2 and F2-Lp was demonstrated using analytical centrifugation with photometric detection where the light transmission profiles did not change throughout the dispersions. Nanoemulsion containing lapachol presented a strong reddish aspect; however, the incorporation of this naphthoquinone did not alter the main physicochemical parameters of NE formulation. The in vitro release study demonstrated a sustained release profile from NE with about 60% of lapachol released within 54 h.

The development of drug delivery systems for photodynamic therapy (PDT) is increasingly demanded due to the hydrophobicity presented by most of photosensitizers molecules. Bacterial cellulose (BC), a highly pure cellulose produced by bacteria, possesses the essential features for applications in drug delivery systems, such as large surface area and excellent loading capacity. BC membranes prepared containing a photosensitizer, chloroaluminum phthalocyanine (ClAlPc), were tested aiming applications as a drug delivery system for PDT skin cancer protocols. BC membranes production was optimized regarding thickness and optical transmission. Thinner membranes lead to higher relative incorporation efficiencies. Skin permeation and retention in vitro tests were performed by using pig's ears as a skin model. ClAlPc was retained at stratum corneum and epidermis/dermis, showing adequate properties for topical administration of ClAlPc. Photophysical studies showed that singlet oxygen production was not affected for ClAlPc compartmentalized in the BC array. BC-ClAlPc membranes did not present cytotoxic effects in vitro.

Itraconazol, um antifúngico de amplo espectro, possui muitos efeitos colaterais e o uso de nanossistemas para a entrega de fármacos tem sido proposto como um método para otimizar a farmacocinética da droga e reduzir os efeitos colaterais. Um procedimento de cromatografia líquida de alta performance (HPLC) utilizando detecção fluorimétrica foi desenvolvido para a determinação de itraconazol em nanopartículas do copolímero de ácido láctico e glicólico, plasma e tecidos. A linearidade, limites de detecção e quantificação, recuperação, precisão, seletividade e estabilidade do método foram estabelecidas. O método desenvolvido foi testado na detecção e quantificação de itraconazol na biodistribuição de nanopartículas administrados intraperitonealmente em camundongos fêmeas Balb/C. Neste estudo foi desenvolvido um método analítico de HPLC com detecção fluorimétrica para quantificação de itraconazole em nanopartículas poliméricas, tecidos e plasma, sendo ele sensível, de baixo custo, viável para uso de rotina e com potencial para aplicação na biodistribuição e estudos farmacocinéticos de itraconazole em nanossistemas.

Itraconazole, a broad-spectrum anti-fungal, has many side effects, and nanosystems for drug delivery have been proposed as a method to optimize the drug's pharmacokinetics and reduce side effects. An high performance liquid chromatography (HPLC) procedure using fluorometric detection was developed for determination of itraconazole in polymeric poly(lactic-co-glycolic acid) nanoparticles, plasma and tissue. Linearity, limits of detection and quantification, recovery, precision, selectivity and stability were established. The developed method was tested in itraconazole detection and quantification of biodistribution of nanoparticles administered intraperitoneally to Balb/C female mice. This study developed an analytical method for HPLC with fluorometric detection for quantification of itraconazole in polymeric nanoparticles, tissue and plasma, which is sensitive, low cost, viable for routine usage and with potential for application in itraconazole biodistribution and pharmacokinetics studies.

A atividade fotodinâmica do cloro(5,10,15,20-tetrafenilporfirinato) de índio(III) (InTPP) in vitro foi investigado para possível uso em terapia fotodinâmica (PDT). O rendimento quântico de oxigênio singlete do InTPP (F D = 0,72) em DMSO foi maior que da 5,10,15,20-tetrafenilporfirina (TPP) (F D = 0,52). Os sítios de ligação entre os fotossensibilizadores e albumina bovina (BSA) são independentes e com células vermelhas de sangue humano (RBC) são cooperativos, com um e quatro sítios de ligação por molécula, respectivamente. As constantes de associação com BSA são (1,15 ± 0,07) × 10(5) e (2,6 ± 0,1) × 10(4) L mol-1 e com RBC são (2,40 ± 0,05) × 10(7) L mol-1 e (7,2 ± 0,2) × 10(4) L mol-1 para InTPP e Photofrin®, respectivamente. O InTPP foi mais eficiente do que Photofrin® em fotooxidar L-triptofano (Trp) e BSA quando maiores concentrações dos fotossensibilizadores foram utilizadas (acima de 14 µmol L-1). O InTPP foi 1,37 a 1,5 vezes mais eficaz em fotooxidar as RBC do que Photofrin®. Nossos resultados indicam que o InTPP pode ser usado para estudos futuros de PDT.

Photodynamic activity of chloro(5,10,15,20-tetraphenylporphyrinato)indium(III) (InTPP) in vitro was investigated for possible use in photodynamic therapy (PDT). The quantum yield of singlet oxygen generation in DMSO of InTPP (F D = 0.72) was higher than 5,10,15,20-tetraphenylporphyrin (TPP) (F D = 0.52). Binding sites between photosensitizers and bovine serum albumin (BSA) are independent while binding sites with human red blood cells (RBC) are cooperatives, with one and four binding sites per molecule, respectively. Binding constants with BSA are (1.15 ± 0.07) × 10(5) and (2.6 ± 0.1) × 10(4) L mol-1 and with RBC are (2.40 ± 0.05) × 10(7) L mol-1 e (7.2 ± 0.2) × 10(4) L mol-1 for InTPP and Photofrin®, respectively. InTPP was more efficient than Photofrin® in the photooxidation of L-tryptophan(Trp) and BSA when higher concentrations (14 µmol L-1) of photosensitizers were used. InTPP was 1.37-1.5 times more effective in the photooxidation of RBC than Photofrin®. Our results indicate that InTPP should be used in future studies of PDT.