Francisco Veiga has completed his PhD at the age of 30years from Coimbra University. He is the dean of Faculty of Pharmacy of University of Coimbra. He has published more than 200 papers in reputed journals.
Statement of the Problem: Are polymeric mixed micelles (Pluronic® F68 and P123) efficient to encapsulate meloxicam and to deliver it by the oral route? Orientation: Morphology was studied by transmission electron microscopy (TEM). Micellar dispersions were placed on Formvar and allowed to dry for 5min. To unveil the usefulness of such formulations concerning physical stability, formulations FM1-FM5 and meloxicam were dissolved in the enteric and gastric medium. After 1 and 2h, we quantified meloxicam in gastric medium and after 3 and 4h, we quantified meloxicam in the enteric medium. Quantification was performed using a UV spectrophotometer and absorbance was taken at 363 nm. To determine encapsulation efficiency (EE), FM1-FM5 were quantified immediately after preparation. Later on, micellar suspensions were centrifuged at 3000g for 15min using Amicon® Ultra 4 Centrifugal filter units, the supernatant was assayed for meloxicam. Cytotoxicity of formulations was assessed in Caco-2 cells by alamarBlue assay, performing screening of crescent concentrations (0.625%, 1.25%, 2.5%, 5%, and 10 %) for each formulation. Findings: Spherical and small sizing micelles were obtained and all formulations significantly increased meloxicam physical stability in enteric medium (meloxicam: 3h 62.563%, 4h 35.890; FM1, FM2, FM3, FM4, FM5: 100%) In gastric medium, despite FM2 and FM3 showed the best results (meloxicam: 1h 1.59%, 2h 1.54%; FM2: 1h 80.339%, 2h 66.281%; FM3: 1h 75.397%, 2h 61.260), all the other formulations showed a significant increase in instability. With the exception of FM1, all formulations demonstrate high EE % (FM1: 35.544±3.919, FM2: 93.162±1.071, FM3: 90.663±1.805, FM4: 89.840±1.991, FM5: 86.607±2.134). FM3 revealed no cytotoxicity in concentrations ranging from 0.625 to 5% while for FM2 no cytotoxicity was found within 0.625 to 2.5% range. Significance: FM2 and FM3 seem to be promising formulations to efficiently encapsulate drugs with low water solubility, as meloxicam.
Ana Isa Perez has experience in analytical chemistry and in specific areas of health. Her beginnings were with her thesis of degree related to the determination of metals in human hair using the technique of atomic absorption with electro thermal detection and after several years researching with optical analysis techniques, she experimented with the electroanalytical techniques in the determination of drugs, in specific with antivirals, finding new alternative, easy and economical methodologies for the quantification. She also has experience in addition to research, in the teaching of analytical chemistry in institutions of international prestige, in her country of origin and in her current country of residence.
There is a significant number of pharmacologically active substances, which have an asymmetric carbon in their structure. Due to the difficulties of separating the enantiomers these drugs are marketed as racemic mixtures although it is known that different enantiomers may possess different activities. The need to develop new alternatives capable of solving these problems has aroused the interest of the scientific community. Sotalol hydrochloride, antiarrhythmic and beta blocker is an example of one of these substances. This medicinal product is administered to patients in the form of a racemate but its R (-) sotalol isomer is known to be approximately 50 times more active than sotalol S (+). In this work, a method has been developed for the determination of the racemic mixture using the differential pulse voltammetric technique having as working electrode, a modified electrode with magnetic nanoparticles (GECE). In this procedure, the sotalol is preconcentrated on the GECE surface and determined in a phosphate buffer solution at pH 7.0. The voltages obtained with the use of this electrode compared to the electrode without modification showed anodic currents at least 5 times higher. The sensor developed stable and selective sensitive responses for determination of sotalol in the racemic mixture, which allowed a detection limit of 1.5x10-8mol L-1 and linearity between 0.2 and 12x10-6mol L-1. The methodology developed was optimized and presented excellent results in commercial tablets and urine. The GECE presented sensitive, stable and selective responses for the determination of sotalol in its separate enantiomeric forms using the VDP technique and provided for the formation of a tetrahedral coordination complex with Zn (II). In the preliminary evaluations, an acceptable limit of detection and limit of determination was obtained.