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The aim of the present work was to modify the exuded gum of Sterculia striata tree by an amination reaction. The viscosity and zero potential of the chicha gum varied as a function of pH. The modification was confirmed by X-ray diffraction (XRD), infrared spectroscopy (FTIR), size exclusion chromatography (SEC), zeta potential, thermogravimetric analysis (TG), and differential scanning calorimetry (DSC). Furthermore, the chemical modification changed the molar mass and surface charge of the chicha gum. In addition, the gums were used in tests for ex vivo mucoadhesion strength, antibacterial activity against the standard strain of Staphylococcus aureus (ATCC 25923), inhibitory activity of α-glucosidase, antioxidant capacity, and viability of Caco-2 cells. Through these tests, it was found that amination caused an increase in the mucoadhesive and inhibitory activity of chicha gum against the bacterium Staphylococcus aureus. In addition, the gums (pure and modified) showed antioxidant capacity and an inhibitory effect against the α-glucosidase enzyme and did not show cytotoxic potential.

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Natural polysaccharides have been investigated as vehicles for oral insulin administration. Because of their non-toxic, renewable, low cost and readily available properties, gums find multiple applications in the pharmaceutical industry. This work aimed to develop a Sterculia striata gum-based formulation associated with additional biopolymers (dextran sulfate, chitosan, and albumin), a crosslinking agent (calcium chloride) and stabilizing agents (polyethylene glycol and poloxamer 188), to increase the oral bioavailability of proteins. Insulin was used as a model drug and the methods used to prepare the formulation were based on ionotropic pregelation followed by electrolytic complexation of oppositely charged biopolymers under controlled pH conditions. The developed formulation was characterized to validate its efficacy, by the determination of its average particle size (622 nm), the insulin encapsulation efficiency (70%), stability in storage for 30 days, and the in vitro mucoadhesion strength (92.46 mN). Additionally, the developed formulation preserved about 64% of initial insulin dose in a simulated gastric medium. This study proposed, for the first time, a Sterculia striata gum-based insulin delivery system with potential for the oral administration of protein drugs, being considered a valid alternative for efficient delivery of those drugs.

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Near-Infrared hyperspectral imaging (HSI-NIR) is a useful technique for pharmaceutical research and industry alike. It can provide important surface information such as the polymorphs quantification and its distribution over the tablet. Several chemometric tools are applied for this purpose, with MCR-ALS and PLS regression being the most common approaches. In this work, a detailed comparison between these two approaches is performed. Beyond a "simple" regression comparison, a comparison of the score images (local quantification) was also evaluated. The system under study is tablets with ternary mixtures of Mebendazol (MBZ) polymorphs, microcrystalline cellulose and magnesium stearate. PLS models, in general, gave lower RMSEP (below 1.7% w/w for the three MBZ polymorphs) than the corresponding MCR-ALS predictions. Analyzing the distributions of the scores in the images of each sample shows clear differences between the PLS and MCR-ALS models. The MCR-ALS gave more chemical meaningful distribution maps for all polymorphs, even though the PLS accurately predicts the average concentration across the image. The problem is that the PLS models used the main spectral regions to quantify each MBZ polymorph, but at the same time undermines the minor spectroscopic changes caused by the different polymorphs. Although this may seem as a minor deviation from the truth, the results clearly show that this deviation is detrimental for the analysis of the spatial distribution of the analytes. These results indicate that the optimal multivariate model for multivariate images depend on the goal of the analysis: global quantification or a distribution analysis.

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Chitosan is a natural copolymer generally available in pharmaceutical and food powders associated with drugs, vitamins, and nutraceuticals. This study focused on monitoring the effect of the morphology and structural features of the chitosan particles for controlling the release profile of the active pharmaceutical ingredient (API) propranolol hydrochloride. Chitosan with distinct molecular mass (low and medium) were used in the formulations as crystalline and irregular particles from commercial raw material, or as spherical, uniform, and amorphous spray-dried particles. The API⁻copolymer interactions were assessed when adding the drug before (drug-loaded particles) or after the spray drying (only mixed with blank particles). The formulations were further compared with physical mixtures of the API with chitin and microcrystalline cellulose. The scanning electron microscopy (SEM) images, surface area, particle size measurements, X-ray diffraction (XRD) analysis and drug loading have supported the drug release behavior. The statistical analysis of experimental data demonstrated that it was possible to control the drug release behavior (immediate or slow drug release) from chitosan powders using different types of particles.

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Several factors can intervene in the molecular properties and consequently in the stability of drugs. The molecular complexes formation often occur due to favor the formation of hydrogen bonds, leading the system to configuration more energy stable. This work we aim to investigate through theoretical and experimental methods the relation between stability and properties of molecular complexes the molecular complex formed between the drugs, efavirenz (EFV), lamivudine (3TC) and zidovudine (AZT). With this study was possible determining the most stable complex formed between the compounds evaluated. In addition the energy and structural properties of the complex formed in relation to its individual components allowed us to evaluate the stability of the same.

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Efavirenz (EFZ) is one of the most used drugs in the treatment of AIDS and is the first antiretroviral choice. However, since it has low solubility, it does not exhibit suitable bioavailability, which interferes with its therapeutic action and is classified as a class II drug according Biopharmaceutical Classification System (low solubility and high permeability). Among several drug delivery systems, the multicomponent systems with cyclodextrins and hydrophilic polymers are a promising alternative for increasing the aqueous solubility of the drug. The present study aimed to develop and characterize in a ternary system of EFZ, MßCD and PVP K30. The results showed that the solid ternary system provided a large increase in the dissolution rate which was greater than 80% and was characterized by DSC, TG, XRD, FT-IR and SEM. The use of the ternary system (EFZ, MßCD and PVP K30 1%) proved to be a viable, effective and safe delivery of the drug. The addition of the hydrophilic polymer appeared to be suitable for the development of a solid oral pharmaceutical product, with possible industrial scale-up and with low concentration of CDs (cyclodextrins).

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UNLABELLED: Abstract Context: Benznidazole (BNZ) is an antiparasitic with trypanocidal properties for the etiological treatment of Chagas disease since 1973. Monitoring the stability of this drug is one of the most effective methods of assessment, forecasting and prevention of problems related to quality product. OBJECTIVE: To investigate the direct and indirect photodegradation of BNZ and to evaluate the interference of the excipients used in the forms dosage solid as well as to shed light on the chemical structure of the degradation products obtained. MATERIALS AND METHODS: To perform this work we adopted the "ICH Harmonised Tripartite Guideline: Photostability Testing of New Drug Substances and Products Q1B" (Guideline Q1B). We used benzonidazole (BNZ) (N-benzil-2-(2-nitroimidazol-1-il) acetamide) (LAFEPE®, Recife, Brazil) and various excipients; beyond high-performance liquid chromatography (HPLC), differential scanning calorimetry (DSC), infrared spectroscopy (IR) and mass spectrometry/mass spectrometry (MS/MS). The indirect photodegradation of BNZ was carried out using physical mixtures with 13 pharmaceutical excipients commonly used in the preparation of solid dosage forms. RESULTS: HPLC and MS/MS techniques were selected for the identification of two photoproducts (PPs) and photoreactions found in direct and indirect tests with the microcrystalline cellulose, considered a critical excipient. DISCUSSION: Despite variations in the infrared spectrometry, differential scanning calorimetry and differential thermogravimetry curves, these techniques are not conclusive since the study of photodegradation of the drug caused decay of 30%, according to the ICH. CONCLUSIONS: The results show that BNZ only undergoes direct photodegradation, since no new PPs were found for a combination of the drug and excipients.

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The present study investigates the release mechanism of benznidazole (BNZ) in solid dispersions with polyethylene glycol 6000 (PEG 6000) and polyvinylpirrolydone K-30 (PVP K-30), with a view to observing the increase in solubility of BNZ in water in the presence of these two hydrophilic polymers. The interaction of BNZ with the polymers was evaluated using scanning electron microscopy, Fourier-transformation infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, and in vitro dissolution tests, and a theoretical study of molecular modeling was also carried out. The drug-polymer interaction was studied trough molecular modeling, using density functional theory with the B3LYP exchange correlation function. The corrected interaction energies were calculated to be -20.9 kJ/mol with PVP and -6.6 kJ/mol with PEG. The experimental and theoretical results indicate that a powerful interaction occurred between BNZ and the polymers, which was especially strong in the case of PVP, and that this interaction contributed to improvement of BNZ solubility.

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