Crystalline structure of the marketed form of Rifampicin: a case of conformational and charge transfer polymorphism

Nogueira, Luciana de Pinho Pessoa; Oliveira, Yara Santiago de; Fonseca, Jéssica de Castro; Costa, Wendell Saraiva; Raffin, Fernanda Nervo; Ellena, Javier; Ayala, A. P.

doi:10.1016/j.molstruc.2017.10.083

Cited by 19 publications

(8 citation statements)

References 17 publications

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“…The first, 1.7, is related to the phenolic hydroxyl groups at C1, C4, and C8. The second value, 7.9, is associated with the nitrogen atoms of the piperazine ring [ 67 ]. According to the calculation presented in a previous work, RIF presents 100% of its molecules ionized at pH 2 due to the protonation of the nitrogen atoms in the piperazine ring.…”

Section: Discussionmentioning

confidence: 99%

Montmorillonite–Rifampicin Nanohybrid for pH-Responsive Release of the Tuberculostatic

et al. 2023

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The present work describes the development of a hybrid and pH-responsive system for rifampicin using the clay mineral ‘montmorillonite’ as a nanocarrier. The influence of operational variables on the drug incorporation process was evaluated using 24 factorial designs. Under optimized conditions, the experiment allowed an incorporated drug dose equivalent to 98.60 ± 1.21 mg/g. Hybrid systems were characterized by different characterization techniques (FTIR, XRD, TGA, DSC, and SEM) to elucidate the mechanism of interaction between the compounds used. Through in vitro release studies, it was possible to verify the efficacy of the pH-dependent system obtained, with approximately 70% of the drug released after sixteen hours in simulated intestinal fluid. The adjustment of the experimental release data to the theoretical model of Higuchi and Korsmeyer–Peppas indicated that the release of rifampicin occurs in a prolonged form from montmorillonite. Elucidation of the interactions between the drug and this raw clay reinforces its viability as a novel carrier to develop an anti-TB/clay hybrid system with good physical and chemical stability.

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Section: Discussionmentioning

confidence: 99%

Montmorillonite–Rifampicin Nanohybrid for pH-Responsive Release of the Tuberculostatic

et al. 2023

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“…The best recognized molecular targets of naphthalenoid ansamycins are bacterial RNA-polymerases (RNAPs), which inhibition is related to antibacterial effects. Thus, targetdirected designing of novel naphthalenoid ansamycin scaffolds, is reasonable way to obtain powerful antibacterials, even better than the clinically-used antibiotics as rifampicin (69), as demonstrated on semisynthetic C(3)-amine analogs, bearing rigid and basic amine arms, enabling zwitterionization. Interestingly, rifampicin-like derivatives possess the ability to interact with viral proteins, which are important at assembling viral membranes, therefore these compounds can be considered at designing novel antiviral agents.…”

Section: Discussionmentioning

confidence: 99%

“…44,63,64 The zwitterionization phenomenon for naphthalenoid ansamycins as rifamycins have also impact on their polymorphism in the crystal state, which is a very important problem discussed at potential pharmaceutical applications of this group of macrolactams in the treatment of bacterial infections (including tuberculosis). 52,[65][66][67][68][69] Thus, the chameleonic features of naphthalenoid ansamycins, concerned with zwitterionic/non-ionic structures and different conformations (sometimes related to stereoisomerism), should be taken into regard at their discussions focused on: the transport, binding with the target (SAR discussions), and bacteria resistance mechanisms.…”

Section: Reviewmentioning

confidence: 99%

Section: Structural Aspects Of Naphthalenoid Ansamycins Influencing T...mentioning

confidence: 99%

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Modifications, biological origin and antibacterial activity of naphthalenoid ansamycins

Skrzypczak

Przybylski

2022

Nat. Prod. Rep.

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“…The electric current and voltage applied were 40 mA and 40 kV, respectively. The opening slit for the beam incident on the sample was 0.6 mm and the samples were scanned within the scan range of 2θ = 5 to 40° [ 27 ].…”

Section: Methodsmentioning

confidence: 99%

DOPE/CHEMS-Based EGFR-Targeted Immunoliposomes for Docetaxel Delivery: Formulation Development, Physicochemical Characterization and Biological Evaluation on Prostate Cancer Cells

et al. 2023

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Docetaxel (DTX) is a non-selective antineoplastic agent with low solubility and a series of side effects. The technology of pH-sensitive and anti-epidermal growth factor receptor (anti-EGFR) immunoliposomes aims to increase the selective delivery of the drug in the acidic tumor environment to cells with EFGR overexpression. Thus, the study aimed to develop pH-sensitive liposomes based on DOPE (dioleoylphosphatidylethanolamine) and CHEMS (cholesteryl hemisuccinate), using a Box–Behnken factorial design. Furthermore, we aimed to conjugate the monoclonal antibody cetuximab onto liposomal surface, as well as to thoroughly characterize the nanosystems and evaluate them on prostate cancer cells. The liposomes prepared by hydration of the lipid film and optimized by the Box–Behnken factorial design showed a particle size of 107.2 ± 2.9 nm, a PDI of 0.213 ± 0.005, zeta potential of −21.9 ± 1.8 mV and an encapsulation efficiency of 88.65 ± 20.3%. Together, FTIR, DSC and DRX characterization demonstrated that the drug was properly encapsulated, with reduced drug crystallinity. Drug release was higher in acidic pH. The liposome conjugation with the anti-EGFR antibody cetuximab preserved the physicochemical characteristics and was successful. The liposome containing DTX reached an IC50 at a concentration of 65.74 nM in the PC3 cell line and 28.28 nM in the DU145 cell line. Immunoliposome, in turn, for PC3 cells reached an IC50 of 152.1 nM, and for the DU145 cell line, 12.60 nM, a considerable enhancement of cytotoxicity for the EGFR-positive cell line. Finally, the immunoliposome internalization was faster and greater than that of liposome in the DU145 cell line, with a higher EGFR overexpression. Thus, based on these results, it was possible to obtain a formulation with adequate characteristics of nanometric size, a high encapsulation of DTX and liposomes and particularly immunoliposomes containing DTX, which caused, as expected, a reduction in the viability of prostate cells, with high cellular internalization in EGFR overexpressing cells.

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Crystalline structure of the marketed form of Rifampicin: a case of conformational and charge transfer polymorphism

Cited by 19 publications

References 17 publications

Montmorillonite–Rifampicin Nanohybrid for pH-Responsive Release of the Tuberculostatic

Montmorillonite–Rifampicin Nanohybrid for pH-Responsive Release of the Tuberculostatic

Modifications, biological origin and antibacterial activity of naphthalenoid ansamycins

DOPE/CHEMS-Based EGFR-Targeted Immunoliposomes for Docetaxel Delivery: Formulation Development, Physicochemical Characterization and Biological Evaluation on Prostate Cancer Cells

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