Micelles have aroused interest due to their ability to assist in the transport of poorly soluble drugs. In this study the mixture of copolymers F127/E45S8 in different proportions (F/ES 30/70, 50/50 and 70/30) was performed to improve the bioavailability of griseofulvin and quercetin. The results of cytotoxicity (MTT assay) revealed that the copolymers F127 and E45S8 had considerable biocompatibility and did not affect the metabolism of human neutrophils. The binary systems were also evaluated by critical micellar concentration (CMC) and thermoresponsive behavior. The CMC values were intermediate to those of the isolated copolymers. The systems maintained the thermoresponsive properties present in F127 making the systems interesting for subcutaneous administration. The systems presented small size, an average range in size from 17 to 38 nm, and the samples prepared with higher hydrophobic proportion presented more uniform sizes. Results suggest stability and the increasing of the nanosystems circulation time. The F/ES 30/70 system has polydispersity smaller than 0.1 and showed an increase of 129 times for quercetin solubility. Thus, it is possible to consider F127/E45S8 micelles as potential nanosystems for poorly soluble drug delivery.

Improving the development of modified release matrix systems strictly depends on selecting an appropriate agent capable of controlling the drug's release. In this study, Adenanthera pavonina galactomannan was investigated as a potential basis for developing a controlled release of rutin. This galactomannan was extracted, purified and characterized by GPC, NMR and FT-IR spectroscopy. The mannose/galactose ratio (M/G) of 1.46 was calculated by the relative area from signals of the anomeric region of 1H-NMR spectrum. The main chain of this galactomannan consists of β(1®4)-D-mannose and α(1®6)-D-galactose linked units (1H-decoupled 13C NMR, 13C DEPT 135º NMR and HSQC spectra). The sustained-release tablets containing rutin and galactomannan were compared with the extensively investigated hydrophilic matrix HPMC. Drug release analysis revealed similar release mechanism for both matrices. A new formulation for controlled drug delivery from water-swellable matrix systems is proposed.

Binary mixtures of block copolymers E114CL20 and E97P69E97 (F127(®)) were prepared in order to tailor a drug delivery system with synergistic effect, concerning dilution stability and high drug solubility. Both reduction of the critical micelle concentrations (CMC) values and enhance hydrophobic drug solubility in F127/E114CL20 mixtures (30-50 wt.%) were observed by addition of the diblock E114CL20, also reaching the best enhancement of drug solubility for mangiferin and carbamazepine.

Melon is one of the most widely consumed fruits in the world. In Brazil, 60% of the production is for domestic consumption, with these fruits deemed to be of lower commercial value. For the first time, pectin has been extracted from this species of melon. So the extraction of this polysaccharide can be used as an alternative to increase the value of the fruit, improving profits in the domestic market where it can be used in many industries. The goal of this study is to determine, quantify, characterize and chemically modify by sulfation pectin from common melon for eventual application as an antithrombotic agent. The acidic, basic and neutral extractions yielded an average of 11%, 14% and 8% respectively. The FTIR spectrum revealed that pectin has a low degree of esterification (DE). The bands which appeared at 833 cm-1 and 1251 cm-1 can be attributed to the vibrations of C-O-S and S=O respectively, showing that the material was sulfated. The 13C NMR spectrum showed consistent carbon galacturonic acid peaks and agrees with the FTIR data and elemental analysis for the sulfation of pectin. The molecular weight (MW) determined by GPC was 7.7 x 105 g mol-1, consistent with pectin.

Alkyl polyglycosides (APGs) are new biodegradable surfactants, non-toxic, synthesized from abundant renewable sources, potentially more appropriate than anionic surfactants. A range of glycosides denoted APG-Cy was synthesized by the Köenig-Knorr reaction using C10, C16 and C18 alcohols and derived from the degradation of amylose from English potato. The molecular structures of the glycosides were characterized by Nuclear Magnetic Resonance (1H and 13C NMR) together with Infrared Spectroscopy (FTIR) and Gel Permeation Chromatography (GPC). The study by NMR allowed the junctions between hydrophilic head groups and hydrophobic tail-groups to be characterized in detail. Conformation of the glycosidic units is 4C1 type with a b anomeric configuration. The formation of glycosides with five glucose rings linked to the alkyl chain was confirmed by 1H NMR and GPC. Liquid crystals identified by the presence of double melting points were observed by Differential Scanning Calorimetry (DSC) showing thermotropic properties. The surface tension (γ) and critical micelle concentration (cmc) were determined by du Noüy method, noting that increasing the length of alkyl chain led to the expected reduction in the cmc. The energies of adsorption and micellization processes calculated from isotherms γ versus ln c (g.dm-3) indicate cooperativeness of hydrophilic and hydrophobic groups.

The surfactants were synthesized by condensing the obtained oligosaccharides of amylose and alkyl phenols extracted from the natural cashew nut shell liquid (nCNSL). The Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared Spectroscopy (FTIR) data showed aromatic ring bands, glycosidic rings, olefins and paraffins. The Nuclear Overhauser Effect Spectroscopy (NOESY) experiments showed that the conformation of the glycosidic units is of the type 4C1 with an α anomeric configuration. The values of Gibbs free energy of micellization (ΔGºmic) indicate that the spontaneity of formed micelles are cardanyl oligoglycosides > cardyl oligoglycosides > anacardyl oligoglycosides. The surface tension (γ) measurements showed that critical micelle concentration (cmc) values were low for surfactants. The study γ versus lnc (g dm-3) indicated that the aggregation behavior of the surfactants is dependent on their structural characteristics, as well as their thermal behavior. The area per molecule (A) values indicates that cardyl oligoglycosides are likely to form aggregates smaller than cardanyl oligoglycosides and anacardyl oligoglycosides. The critical packing parameter (cpp) indicates that the aggregates are of the vesicles and bilayers.

The non-commercial copolymers E45S8, E45S17 and their mixtures with Pluronic® P123 (E21P67E21) were studied as carriers of the model drug griseofulvin. Critical micelle concentration (cmc) (dye solubilisation method), drug solubilisation capacity (Scp and Sh) determined by ultraviolet-visible (UV-Vis) spectroscopy and 1H nuclear magnetic resonance (1H NMR) and cytotoxicity (LDH activity in human neutrophils) were studied. E45S17 1.0 wt.% dispersions presented colloidal aggregates limiting its Scp in comparison to E45S8, but in 0.1 wt.% solutions this phenomenon seemed to be absent and E45S17 presented a higher Scp. The mixtures that showed the best Scp results contained 50% of P123 and presented low cmc. An evaluation of literature data suggested a minimum Em content of 62% in EmSn copolymers below which the increase of Sn length does not lead to an increase of Sh. The results suggested no toxicity of the copolymers on human neutrophils, supporting the use of P123 and poly(styrene oxide) containing copolymers as drug carriers.