Pooling of sputum samples to increase tuberculosis diagnostic capacity in Brazil during the COVID-19 pandemic

Objectives We assessed whether combining (pooling) four individual's samples and testing with Xpert Ultra has the same accuracy as testing samples individually, as a more efficient testing method. Methods We conducted a cross-sectional study of individuals with presumptive TB attending primary health care or general hospital facilities in Alagoas, Brazil. Sputum samples of four consecutive individuals were pooled and the pool and individual samples were tested with Xpert Ultra. The agreement of the tests was compared using kappa statistics. We estimated the sensitivity and specificity of pooling using the individual test as the reference standard and potential cartridge savings. Results Three hundred and ninety-six participants were tested. Ninety-five (24.0%) individual samples were MTB-positive, 300 (75.8%) MTB-not detected, including 20 MTB-trace, and one reported an error. Ninety-nine pools of four samples were tested, of which 62 (62.6%) had MTB-detected and 37 (37.4%) MTB-not detected, including six (6.1%) with MTB-trace. The agreement of individual and pooled testing was 96.0%. Pooling had sensitivity of 95.0% (95%CI 86.9%–99%), specificity of 97.1% (95%CI 85.1%–99.9%) and Kappa of 0.913. The method saved 12.4% of cartridge costs. Conclusion The pooled testing of specimens had a high level of agreement with individual testing. Pooling of samples for testing improves the efficiency of testing, potentially enabling the screening and testing of larger numbers of people more cost-effectively

Host–guest interactions between benznidazole and beta-cyclodextrin in multicomponent complex systems involving hydrophilic polymers and triethanolamine in aqueous solution

Association of hydrophilic compounds with cyclodextrins to increase drug solubility has been extensively studied in aqueous solution. However, the mechanism of interaction among these components remains unclear. In this study, the mechanism of interaction of seven different hydrophilic polymers (HPs) and triethanolamine (TEA) in aqueous solution with beta-cyclodextrin (β-CD) to modify the aqueous solubility of benznidazole (BNZ) was well investigated using solubility diagrams, thermodynamic experiments, molecular modeling and NMR studies. Solubility diagrams in different pH values confirmed linear soluble BNZ-β-CD inclusion complexes, with 1:1 stoichiometry (AL type). A synergistic effect in the association of TEA with BCD did not occur, due to competition between TEA and BNZ β-CD cavity, which led to obtain inclusion complexes with limited solubility (B type). The increment of BNZ solubility occurred only at higher TEA concentrations by cosolvency mechanism, which was evidenced by solubility diagrams, molecular modeling and NMR studies. The association of different hydrophilic polymers with β-CD contributes thermodynamically to stabilize the formed complexes, in which POL 407 and PVA increased considerably the observed K1:1 value. An enthalpic contribution of hydrophilic polymers led to enhance the spontaneity of BNZ-β-CD interaction and a slight increasing in entropy change (ΔS) did possible to stabilize the interaction between BNZ and β-CD.Fil: Melo, Polyanne Nunes de. Universidade Federal do Rio Grande do Norte; BrasilFil: Barbosa, Euzébio Guimarães. Universidade Federal do Rio Grande do Norte; BrasilFil: Caland, Lília Basílio de. Universidade Federal do Rio Grande do Norte; BrasilFil: Carpegianni, Hugo. Universidade Federal do Rio Grande do Norte; BrasilFil: Garnero, Claudia. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Longhi, Marcela Raquel. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernandes Pedrosa, Matheus de Freitas. Universidade Federal do Rio Grande do Norte; BrasilFil: Silva Júnior, Arnóbio Antônio da. Universidade Federal do Rio Grande do Norte; Brasi

Interaction pathways of specific co-solvents with hydroxypropyl-β-cyclodextrin inclusion complexes with benznidazole in liquid and solid phase

The main purpose of the study was to assess the mechanism whereby the co-solvents triethanolamine (TEA) and 1-methyl-2-pyrrolidone (NMP) interacted with hydroxypropyl-beta-cyclodextrin (HP-β-CD) in ternary associations for improving the solubility and dissolution rate of the insoluble ingredient benznidazole (BNZ). In liquid phase, the solubility diagrams and Job's plot results were further explored by in silico molecular modeling and experimental 1H NMR spectroscopy studies. The structure of the inclusion complexes in the binary and ternary association were established. The competition of NMP with the drug for the HP-β-CD cavity was evidenced, while TEA stabilized the drug-CD interactions, forming ternary complexes. FTIR analysis confirmed distinct intermolecular interactions among the compounds in the different solid dispersions prepared by physical mixture (PM) and spray drying (SD). The co-solvents improved the drug dissolution performance from PM ternary associations due to their enhanced wettability of particles changing the drug-CD interaction. In addition to the SD samples exhibiting spherical particles, the co-solvents increased the crystallinity of drug in the particles and the ternary associations did not reproduce the drug dissolution rate identified in the PM samples. The experimental results proved the importance of the co-solvents to improve the drug dissolution performance from ternary complexes and established the mechanism whereby these substances worked together with the CD in a new and promising raw material. Due to the high temperature, the spray drying was not a suitable method for preparing the specific ternary complexes.Fil: de Melo, Polyanne N.. Universidade Federal do Rio Grande do Norte; BrasilFil: Barbosa, Euzébio G.. Universidade Federal do Rio Grande do Norte; BrasilFil: Garnero, Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: de Caland, Lilia B.. Universidade Federal do Rio Grande do Norte; BrasilFil: Fernandes Pedrosa, Matheus F.. Universidade Federal do Rio Grande do Norte; BrasilFil: Longhi, Marcela Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: da Silva Júnior, Arnóbio Antônio. Universidade Federal do Rio Grande do Norte; Brasi

Triethanolamine Stabilization of Methotrexate-β-Cyclodextrin Interactions in Ternary Complexes

The interaction of methotrexate (MTX) with beta-cyclodextrin (β-CD) in the presence of triethanolamine (TEA) was investigated with the aim to elucidate the mechanism whereby self-assembly cyclodextrin systems work in association with this third component. Solubility diagram studies showed synergic increment of the MTX solubility to be about thirty-fold. Experiments using 2D ROESY and molecular modeling studies revealed the inclusion of aromatic ring III of the drug into β-CD cavity, in which TEA contributes by intensifying MTX interaction with β-CD and stabilizes MTX:β-CD:TEA ternary complex by electrostatic interaction. The maintenance of these interactions in solid phase was also studied in ternary MTX:β-CD:TEA and comparisons were made with freeze dried binary MTX:β-CD and physical mixtures. FTIR studies evidenced that MTX–β-CD interaction remained in solid ternary complexes, which was also supported by thermal (differential scanning calorimetry (DSC), thermogravimetric analysis (TG)/first derivative of TG analysis (DTG) and C,N,H elementary analysis) and structural (X-ray diffraction analysis, (XRD)) studies, mainly regarding the increment of drug stability. The efficient in vitro drug dissolution studies successfully demonstrated the contribution of ternary complexes, which highlights the importance of this possible new raw material for further applications in drug delivery systemsFil: Barbosa, Jahamunna A.. Universidade Federal do Rio Grande do Norte; BrasilFil: Zoppi, Ariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: Quevedo, Mario Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: de Melo, Polyanne. Universidade Federal do Rio Grande do Norte; BrasilFil: de Medeiros, Arthur S. A. Universidade Federal do Rio Grande do Norte; BrasilFil: Streck, Leticia. Universidade Federal do Rio Grande do Norte; BrasilFil: de Oliveira, Alice R.. Universidade Federal do Rio Grande do Norte; BrasilFil: Fernandes Pedrosa, Matheus F.. Universidade Federal do Rio Grande do Norte; BrasilFil: Longhi, Marcela Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Unidad de Investigación y Desarrollo en Tecnología Farmacéutica; ArgentinaFil: da Silva Junior, Arnobio A.. Universidade Federal do Rio Grande do Norte; Brasi

Pooling of sputum samples to increase tuberculosis diagnostic capacity in Brazil during the COVID-19 pandemic

Objectives: We assessed whether combining (pooling) four individual's samples and testing with Xpert Ultra has the same accuracy as testing samples individually as a more efficient testing method. Methods: We conducted a cross-sectional study of individuals with presumptive tuberculosis attending primary health care or general hospital facilities in Alagoas, Brazil. The sputum samples of four consecutive individuals were pooled and the pool and individual samples were tested with Xpert Ultra. The agreement of the tests was compared using kappa statistics. We estimated the sensitivity and specificity of pooling using the individual test as the reference standard and potential cartridge savings. Results: A total of 396 participants were tested. A total of 95 (24.0%) individual samples were Mycobacterium tuberculosis (MTB)-positive, 300 (75.8%) “MTB not detected”, including 20 “MTB trace”, and one reported an error. A total of 99 pools of four samples were tested, of which 62 (62.6%) had MTB detected and 37 (37.4%) MTB not detected, including six (6.1%) with MTB trace. The agreement between individual and pooled testing was 96.0%. Pooling had a sensitivity of 95.0% (95% confidence interval 86.9-99%), specificity of 97.1% (95% confidence interval 85.1-99.9%), and kappa of 0.913. The method saved 12.4% of cartridge costs. Conclusion: The pooled testing of specimens had a high level of agreement with individual testing. The pooling of samples for testing improves the efficiency of testing, potentially enabling the screening and testing of larger numbers of individuals more cost-effectively