Beta-lapachone (βlap) is a naphthoquinone derived from Lapachol, a substance extracted from the Bignoniaceae family of trees, genus Tabebuia; found in the Northern and Northeastern regions of Brazil. ...βlap shows excellent pharmacological activity as an antiparasitic, antitumor, and anti-inflammatory drug, but its water solubility is low, which decreases its bioavailability. This work aims to evaluate the solubility and dissolution rate of βlap from solid dispersions obtained by the Spray Drying technique and compare them with the physical mixture (PM) of compounds. βlap solid dispersions were prepared with polyethylene glycol (PEG 6000) and polyvinylpyrrolidone (PVP K30) at 1: 2 (w/w) ratio and characterized by thermal analysis differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), solubility tests, dissolution profile assays and analyzed by mathematical models to link to the system properties. βlap/PVP solid dispersion provided a 15-fold increase in dissolution rate compared to pristine βlap in the first 5 min. The release constants obtained from Korsmeyer–Peppas and Weibull models demonstrate that βlap is released more rapidly from the PVP system produced by Spray Drying than by PM. The thermal analysis suggests that the βlap was successfully encapsulated into spherical shape and uniform size distribution microparticles produced by SD/PVP, as shown by the SEM technique. In addition, it afforded about 9-fold higher solubility than the free βlap. The results of DSC and XRD showed a tendency of the βlap crystallinity to decrease. FTIR showed intermolecular interaction between drug and polymer molecules (PVP and PEG). Thus, the results suggest that βlap/PVP-based solid dispersions can be successfully applied in pharmaceutical formulations.
β-lapachone (βlap) has shown potential use in various medical applications. However, its poor solubility has limited its systemic administration and clinical applications. The aim of this work is to ...develop solid dispersions of βlap using poly (ethylene glycol) (PEG 6000) and polyvinylpyrrolidone (PVP K30) as hydrophilic polymers and evaluate the dissolution rate in aqueous medium. Solid dispersions were prepared by solvent evaporation method using different weight ratios of βlap and hydrophilic polymer (1:1, 1:2, and 1:3). Characterization performed by differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy showed that βlap was molecularly dispersed within the polymer matrix. The in vitro dissolution tests showed an enhancement in the dissolution profile of βlap as solid dispersions prepared in both PVP and PEG, although the former showed better results. The drug:polymer ratio influenced βlap dissolution rate, as higher amounts of hydrophilic polymer led to enhanced drug dissolution. Thus, this study demonstrated that solid dispersions of βlap in PVP offers an effective way to overcome the poor dissolution of βlap.
Beta-lapachone (betalap) is a naphthoquinone derived from Lapachol, a substance extracted from the Bignoniaceae family of trees, genus Tabebuia; found in the Northern and Northeastern regions of ...Brazil. betalap shows excellent pharmacological activity as an antiparasitic, antitumor, and anti-inflammatory drug, but its water solubility is low, which decreases its bioavailability. This work aims to evaluate the solubility and dissolution rate of betalap from solid dispersions obtained by the Spray Drying technique and compare them with the physical mixture (PM) of compounds. betalap solid dispersions were prepared with polyethylene glycol (PEG 6000) and polyvinylpyrrolidone (PVP K30) at 1: 2 (w/w) ratio and characterized by thermal analysis differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), solubility tests, dissolution profile assays and analyzed by mathematical models to link to the system properties. betalap/PVP solid dispersion provided a 15-fold increase in dissolution rate compared to pristine betalap in the first 5 min. The release constants obtained from Korsmeyer-Peppas and Weibull models demonstrate that betalap is released more rapidly from the PVP system produced by Spray Drying than by PM. The thermal analysis suggests that the betalap was successfully encapsulated into spherical shape and uniform size distribution microparticles produced by SD/PVP, as shown by the SEM technique. In addition, it afforded about 9-fold higher solubility than the free betalap. The results of DSC and XRD showed a tendency of the betalap crystallinity to decrease. FTIR showed intermolecular interaction between drug and polymer molecules (PVP and PEG). Thus, the results suggest that betalap/PVP-based solid dispersions can be successfully applied in pharmaceutical formulations.
Composição centesimal e de minerais em cascas de frutas Gondim, Jussara A. Melo(IDepartamento de Farmácia); Moura, Maria de Fátima V.(IDepartamento de Farmácia); Dantas, Aécia S.(Departamento de Química Laboratório de Química Analítica) ...
Ciência e tecnologia de alimentos,
12/2005, Letnik:
25, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Informações sobre a composição de alimentos de origem agrícola cultivados em solos brasileiros são escassas, e mais ainda de alimentos provenientes do Nordeste. O desconhecimento dos princípios ...nutritivos dos alimentos induz ao mau aproveitamento, o que ocasiona o desperdício de toneladas de recursos alimentares. Com o objetivo de incentivar o reaproveitamento de alimentos e oferecer uma alternativa nutritiva de dieta a baixo custo, foram analisadas as cascas de algumas frutas que normalmente são desprezadas. No presente trabalho, foi determinada a composição centesimal de 7 elementos minerais com importância nutricional (Ca, Cu, Fe, K, Mg, Na, Zn) em 7 tipos diferentes de cascas de frutas: abacate, abacaxi, banana, mamão, maracujá, melão e tangerina, cultivadas no Estado do Rio Grande do Norte. As análises químicas mostraram que as cascas das frutas apresentam, em geral, teores de nutrientes maiores do que os das suas respectivas partes comestíveis, conforme verificado na literatura. Desta forma, pode-se considerar que as cascas das frutas analisadas podem ser úteis como fontes alternativas de alimento ou como ingredientes para obtenção de preparações processadas.
Information on the composition of Brazilian foods is scant, mainly of Northeastern origin. Still, the ignorance of the nutritious principles of the foods, as well as improper use, cause the waste of tons of alimentary resources. With the objective of motivating the reuse of foods and offering a nutritious alternative of diet at a low cost, the peels of some fruits were analyzed, which are usually discarded. In the present work, it was determined the centesimal composition and 7 mineral elements with nutritious importance (Ca, Cu, Fe, K, Mg, Na, Zn) in 7 different types from peels of fruits: avocado, pineapple, banana, papaya, passion fruit, melon and tangerine, cultivated in Rio Grande do Norte State. The chemical analyses showed that the peels of the fruits present, in general, larger content of nutrients than the respective edible parts verified in the literature. This way, it can be considered that the peels of the analyzed fruits can be used as alternative source of food or as ingredients as to obtain processed preparations.
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