The applicability of solid state characterization and analytical techniques for reference chemical substance certification: Resolution of the Collegiate Board (RDC) 166/2017 by National Health Surveillance Agency (ANVISA)

Reference chemical substances called primary reference are used which are marketed by official compendia both nationally and internationally in the pharmaceutical industry as a tool for identification and quantification during pre-formulation, development/analytical validation and quality control studies. The reference or primary standards are almost always imported and resold in the Brazilian market as a consequence, increasing the cost in relation to the sample amount (little amount of mass in mg per bottle). On July 24, 2017, the National Health Surveillance Agency (ANVISA) published the Resolution of the Collegiate Board (RDC) number 166, which deals with the validation of analytical methods. The Chapter III of this resolution is intended for reference chemical substances and, in Art. 14 § 1, the RDC 166/2017 allows the use of characterized reference chemical substances in the analytical validations. The characterization study is planned according to the chemical structure of the substance to be characterized and within this new regulation, solid-state characterization and analytical chemistry stands out as an essential ally corroborating with the evolution of the number of publications in the literature regarding this subject in the google scholar database as shown in Figures 1 and 2.

Capturing the Most Active State of a Palladium(0) Cross-Coupling Catalyst

Zerovalent palladium complexes are ubiquitous active species in modern cross-coupling reactions that comprise many premier methods for the construction of C–C and C–heteroatom bonds in organic synthesis. While palladium(0) complexes stabilized by two or more dative ligands are widely known, the most active form of Pd(0) coordinated by a single ancillary ligand (“monoligated Pd(0)”) has long eluded direct characterization. We report the synthesis and unambiguous solution- and solid-state characterization of functionally 12-electron Pd(0) complexes coordinated by a single tri(1-adamantyl)phosphine (PAd3) ligand. Access to these fleeting intermediates was achieved by enabling B-to-Pd transmetalation reactions that occur at cryogenic temperature. This work opens new avenues to experimentally interrogate highly reactive on-cycle Pd(0) catalysts and their structure-dependent reactivity and speciation, which should be broadly informative in continuing studies of catalytic processes featuring the prevalent Pd(0)/Pd(II) redox couple.

Utilising Co-Axial Electrospinning as a Taste-Masking Technology for Paediatric Drug Delivery

The present study describes the use of two taste-masking polymers to fabricate a formulation of chlorpheniramine maleate for paediatric administration. Co-axial electrospinning was utilized to create layered nanofibres; the two polymers, Eudragit® E PO and Kollicoat® Smartseal, were alternated between the core and the shell of the system in order to identify the optimum taste-masked formulation. The drug was loaded in the core on all occasions. It was found that the formulation with Kollicoat® Smartseal in the core with the drug, and Eudragit® E PO in the shell showed the most effective taste-masking compared to the other formulations. These fibres were in the nano-range and had smooth morphology as verified by scanning electron microscopy. Solid-state characterization and thermal analysis confirmed that amorphous solid dispersions were formed upon electrospinning. The Insent E-tongue was used to assess the taste-masking efficiency of the samples, and it was found that this formulation was undetectable by the bitter sensor, indicating successful taste-masking compared to the raw version of the drug. The E-tongue also confirmed the drug’s bitterness threshold as compared to quinine HCl dihydrate, a parameter that is useful for formulation design and taste-masking planning.