Caracterização físico-química do fármaco antichagásico benznidazol

Currently, benznidazole (BNZ) is a unique therapeutic alternative available in Brazil to treat Chagas disease. Despite its traditional medical use, little is known about the chemical nature of this drug. A detailed study of the physicochemical properties of BNZ was performed using multiple assays. Thermal, diffractometric, morphological and reological drug profiles were obtained. The partition coefficient and solubility results allowed this drug to be classified as a class IV drug according to the biopharmaceutical classification system. This information will be useful for the development of more effective BNZ formulations and for establishing the quality profile of BNZ

Recent advances in the treatment of Chagas disease

Descoberta há cem anos, a doença de Chagas afeta a mais de quinze milhões de pessoas em toda a América Latina e, ainda hoje, não há tratamentoeficaz. O fármaco benznidazol, utilizado como única opção de tratamento no Brasil, é ineficaz na fase crônica da doença. Problemas relacionados à biodisponibilidade do medicamento comercial limitam sua eficácia, principalmente na fase crônica, quando os parasitos estão confinados em tecidos profundos e em lenta replicação. Nesse contexto, pesquisas lideradas por grupos brasileiros e argentinos vêm sendo conduzidas com o objetivo de desenvolver formulações de benznidazol mais eficientes. Diversas formas farmacêuticas sólidas e líquidas foram propostas nos últimos anos com resultados pré-clínicos promissores, sendo descritas melhorias acentuadas nas características farmacocinéticas desse fármaco. Espera-se que as formas inovadoras apresentadas possam ser avaliadas em ensaios clínicos e incorporadas à produção industrial em breve.Discovered about a hundred years ago, Chagas disease currently affects more than fifteen million people in Latin America, and it still remains without any effective treatment. Although benznidazole has been used as the only pharmacotherapeutic option to treat Chagas disease in Brazil, it is ineffective in the chronic phase of the disease, when the parasites are confined to deep tissue layers and slowly replicate. This happens mainly due to problems related to the bioavailability of the drug, which is currently in the market. In this context, Brazilian and Argentinean research groups have conducted studies to develop more efficient benznidazole formulations. Several solid and liquid formulations have been proposed over the last few years with promising preclinical results. Improvements in the pharmacokinetic properties of this drug have been described. Therefore, it is expected, that such innovative drugs and formulations be assessed in clinical trials and soon incorporated to industrial production.Fil: da Cunha Filho, Marcílio Sérgio Soares . Universidade Do Brasilia; BrasilFil: de Sá-Barreto, Lívia Cristina lira . Universidade Do Brasilia; BrasilFil: Leonardi, Darío. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Lamas, Maria Celina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; ArgentinaFil: Salomon, Claudio Javier. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Química Rosario; Argentin

Thermal and physical properties of crude palm oil with higher oleic content

Interspecific hybridization of oil palms (E. guineensis × E. oleifera) was initially exploited to provide disease resistance and, consequently, increased oleic acid content. Besides the growing importance of this cultivar to the market, there is little information about this oil’s properties. In this context, this study aimed to determine a comprehensive physicochemical and thermal characterization of hybrid palm oil (HOPO) compared with the better-known African palm oil (APO). Differences in the distribution of fatty acids, carotenoids, and tocols were observed. Minor differences in density and viscosity were found between the oils, with no relevance for the materials’ processing design. Nevertheless, HOPO showed unique crystallization behavior, which potentially can affect industrial operations, such as fractionation. HOPO did not present the two thermal characteristic regions of APO, attributed to olein and stearin fractions. The HOPO demonstrated a decrease in the melting point of more than 3 °C in relation to APO, and a reduction in the crystallization point of more than 6 °C. Furthermore, besides the higher content of unsaturated fatty acids, HOPO was more stable than APO due to a higher antioxidant content. These results could be useful to establish operation conditions for processes using palm oil from hybrid oil palm

Pouteria macrophylla fruit extract microemulsion for cutaneous depigmentation : evaluation using a 3D pigmented skin model

Here, we verify the depigmenting action of Pouteria macrophylla fruit extract (EXT), incorporate it into a safe topical microemulsion and assess its effectiveness in a 3D pigmented skin model. Melanocytes-B16F10- were used to assess the EXT effects on cell viability, melanin synthesis, and melanin synthesis-related gene transcription factor expression, which demonstrated a 32% and 50% reduction of intra and extracellular melanin content, respectively. The developed microemulsion was composed of Cremophor EL®/Span 80 4:1 (w/w), ethyl oleate, and pH 4.5 HEPES buffer and had an average droplet size of 40 nm (PdI 0.40 ± 0.07). Skin irritation test with reconstituted epidermis (Skin Ethic RHETM) showed that the formulation is non-irritating. Tyrosinase inhibition was maintained after skin permeation in vitro, in which microemulsion showed twice the inhibition of the conventional emulsion (20.7 ± 2.2% and 10.7 ± 2.4%, respectively). The depigmenting effect of the microemulsion was finally confirmed in a 3D culture model of pigmented skin, in which histological analysis showed a more pronounced effect than a commercial depigmenting formulation. In conclusion, the developed microemulsion is a promising safe formulation for the administration of cutite fruit extract, which showed remarkable depigmenting potential compared to a commercial formulation

Follicular-targeted delivery of spironolactone provided by polymeric nanoparticles

This study proposes developing a topical formulation based on poly-ε-caprolactone (PCL) or methacrylic acid/methyl methacrylate copolymer (EL100) nanoparticles to enable a safer and more effective therapy of alopecia and acne with spironolactone. The effect of the size of the nanoparticle on follicular-targeted drug delivery is also verified. Compatibility studies based on thermal analyses and complementary techniques showed a small interaction of the drug with excipients, which may not compromise the drug stability. PCL nanoparticles of 180.0 ± 1.6 and 126.8 ± 1.0 nm, and EL100 nanoparticles of 102.7 ± 7.1 nm were then prepared. All nanoparticles entrapped more than 75 % of spironolactone, were physically stable, and stabilized the drug for at least 90 days. They were also non-irritant according to HET-CAM tests. Drug release from the nanoparticles was reduced in aqueous buffer media but fast when in contact with oil. Finally, in vitro skin penetration experiments revealed the largest nanoparticles (of 180 nm) targeted drug delivery to the hair follicles 5-fold (p < 0.05) more than the control solution, 2.1-fold (p < 0.05) more than nanoparticles produced with the same polymer (PCL) but with smaller size (123 nm), and 4.9-fold (p < 0.05) more than the 102-nm E100 nanoparticles. In conclusion, follicular targeting can be adjusted according to nanoparticle size, and this work succeeded in obtaining polymeric nanoparticles adequate to enable topical treatment of acne and alopecia with spironolactone

Targeted clindamycin delivery to pilosebaceous units by chitosan or hyaluronic acid nanoparticles for improved topical treatment of acne vulgaris

We developed chitosan or hyaluronic acid nanoparticles to entrap clindamycin and evaluated for the first time the impact of these two polymeric nanosystems on the targeted drug delivery to the pilosebaceous units, considering the sebaceous characteristics of skin affected by acne. Chitosan and hyaluronic acid nanoparticles respectively presented diameters of 362 ± 19 nm and 417 ± 9 nm (PDI < 0.47), entrapped 42 % and 48 % of the clindamycin content (drug loading of 8.8 % and 0.5 %) and had opposite surface charges (+27.7 ± 0.9 mV and -30.2 ± 2.7 mV). Although only the hyaluronic acid nanoparticles showed increased deposition of the drug into the pilosebaceous structures, both nanoparticles revealed enhanced targeted delivery of clindamycin to these structures as compared to commercial formulation (53 ± 20 % and 77 ± 9% of the total drug that penetrated the skin was found on the pilosebaceous units from, respectively, chitosan and hyaluronic acid nanoparticles). Remarkably, the “targeting potential” of the nanoparticles was more pronounced when the skin was pretreated to simulate a sebaceous condition. In conclusion, both polymeric nanocarriers targeted drug delivery to the pilosebaceous structures at different extensions and, in the case of oily skin conditions, such targeting was increased

Compatibility and stability studies involving polymers used in fused deposition modeling 3D printing of medicines

One of the challenges for developing three-dimensional printed medicines is related to their stability due to the manufacturing conditions involving high temperatures. This work proposed a new protocol for preformulation studies simulating thermal processing and aging of the printed medicines, tested regarding their morphology and thermal, crystallographic, and spectroscopic profiles. Generally, despite the strong drug-polymer interactions observed, the chemical stability of the model drugs was preserved under such conditions. In fact, in the metoprolol and Soluplus® composition, the drug's solubilization in the polymer produced a delay in the drug decomposition, suggesting a protective effect of the matrix. Paracetamol and polyvinyl alcohol mixture, in turn, showed unmistakable signs of thermal instability and chemical decomposition, in addition to physical changes. In the presented context, establishing protocols that simulate processing and storage conditions may be decisive for obtaining stable pharmaceutical dosage forms using three-dimensional printing technology

The influence of sebaceous content on the performance of nanosystems designed for the treatment of follicular diseases

Nanostructures have been proposed as drug delivery systems in the treatment of hair follicle-related conditions because of their well-reported tendency to accumulate into the hair follicle shafts extending drug release. However, little is known about colloids behavior under diseased conditions as acne vulgaris, folliculitis, hidradenitis suppurativa, or capillary keratosis, in which there is an excess of sebum secretion that clogs the hair follicles. Here, we evaluated the influence of the sebaceous content on the performance of nanosystems by using an in vitro sebaceous skin model, in which the skin was massaged with a mixture of mutton tallow and vegetable oil in a 1:1 (w/w) preceding the permeation experiments. A nanostructured lipid carrier containing clindamycin phosphate (~90% of encapsulation efficiency) was used as a formulation model. Nanoparticles presented a mean diameter of 391.9 ± 8.6 nm, PDI of 0.16 ± 0.05, and positive zeta potential (+18.5 ± 1.5 mV). Stability studies confirmed nanoparticles were stable throughout all experiments, and drug release studies confirmed the controlled release profile. The results indicated the nanosystem performance was superior to the free drug in targeting the hair follicle in conventional skin permeation experiments, but no advantages of the colloidal system were observed when using the sebaceous skin model. Hence, the sebaceous content hampered nanoparticles deposition into the hair follicle shafts. In conclusion, the physiological skin condition must be considered when designing targeted drug delivery systems. The novel sebaceous skin model proposed in this paper can be used to evaluate, in a more realistic condition, the performance of the nanostructured systems intended for topical drug delivery in conditions of excess sebaceous secretion

Carvedilol : decomposition kinetics and compatibility with pharmaceutical excipients.

Carvedilol (CARVE) is an important cardiovascular drug with limited bioavailability. To improve its therapeutic performance, the investigation of new dosage forms is of great interest due its relevance in clinical applications. Therefore, the aim of this work was to evaluate the stability of CARVE and its drug–excipient compatibility to support its pharmaceutical development. Kinetic analysis under isothermal conditions using thermogravimetry was performed to determine the activation energy of CARVE through an Arrhenius plot. Differential scanning calorimetry, Fourier transform infrared spectroscopy, and optical microscopy were used to test binary mixtures of CARVE and selected excipients. The activation energy of CARVE was 81.2 kJ mol-1, and from the compatibility studies, all the excipients showed strong thermal interactions, presenting changes in the melting profile of the drug. In addition, analytical assays revealed no physical or chemical changes; because of this, all eight excipients studied are considered compatible and are recommended in formulations containing CARVE. All the evidence together attests to the low chemical reactivity of CARVE and provides useful information for the development of new pharmaceutical formulations containing CARVE