Promotion of cutaneous penetration of nifedipine for nanoemulsion

ABSTRACT This article reports the development and characterization of a nanoemulsion (NE) able to improve the cutaneous penetration of nifedipine. NE with nifedipine was development and characterized, presenting droplet size of 20 nm with low polydispersity index (IP<0.1), spherical shape without aggregation, pH compatible with typical skin levels and stability evaluated by seven months. In the permeation studies, a classical formulation based in an oil/water cream containing nifedipine was used for comparison with NE. Nanoemulsion promoted and improved the retention of nifedipine in the epidermis and dermis in relation to classical formulation. This promoting effect is related to the nanometric size of the droplets of the NE (20 nm), which give him a large superficial area, favoring the contact of the nanocarrier with the skin surface. The NE was efficient in promoting accumulation of nifedipine in the dermis, which is the site of vasodilation action. NE was not irritating according to the primary dermal irritation tests. NE is a promising release system to promote cutaneous penetration of nifedipine and can be used in the future in clinical trials to promote healing of lesions caused by peripheral vascular diseases.

Development, characterization and evaluation of the dissolution profile of sulfasalazine suspensions / Desenvolvimento, caracterização e avaliação do perfil de dissolução de suspensões sulfasalazina

This paper reports the development, characterization and in vitrodissolution behavior of sulfasalazine suspensions for treatment of chronic intestinal inflammatory diseases. Three formulations were developed, from powdered sulfasalazine obtained from different suppliers. The sulfasalazine was characterized regarding concentration, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), X-Ray Diffraction (XRD), particle size distribution, polydispersion and solubility. The suspensions were developed and characterized regarding pH, viscosity, density, particle size, sedimentation volume, concentration and dissolution. The pH values were slightly acidic. The method of preparing the suspensions reduced the particle sizes and made the size distribution more homogeneous. The dissolution studies showed that the sulfasalazine suspensions had low solubility in acidic media, but dissolve quickly, reaching levels of 85%, in neutral media or media containing 0.5% of surfactants such as polysorbate 80. Besides this, the sulfasalazine suspensions were classified as having immediate dissolution because they reached dissolution levels near 100% in 20 minutes...

O trabalho reporta o desenvolvimento, caracterização e estudo in vitro de dissolução de suspensões de sulfassalazina para uso em doenças inflamatórias crônicas intestinais. Desenvolveram-se três formulações baseadas em fornecedores diferentes de pó de sulfassalazina. A sulfassalazina foi caracterizada quanto a Teor, Infravermelho por Transformada de Fourier (FTIR), Calorimetria Diferencial de Varredura (DSC), Difração de Raios-X (XRD), distribuição de tamanho das partículas, índice de polidispersão e solubilidade. A suspensão foi desenvolvida e caracterizada quanto a pH, viscosidade, densidade, tamanho de partícula, volume de sedimentação, teor e estudo de dissolução. Os valores de pH determinados foram levemente ácidos. O método de preparo das suspensões reduziu o tamanho das partículas e tornou a distribuição de tamanho mais homogênea. Os estudos de dissolução mostraram que a suspensão de sulfassalazina tem problemas de solubilidade em meios de caráter ácido, entretanto, sofre dissolução rápida acima de 85% em meios neutros ou contendo 0,5% de tensoativos como Polissobato 80. Além disso, as suspensões de sulfassalazina foram classificadas como formulações de dissolução imediata porque a partir de 20 minutos sofrem dissolução em torno de 100%...