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In the present investigation, a novel approach towards a complete separation of all 15 protease and reverse transcriptase inhibitors which are currently approved for use in highly active antiretroviral therapy in a single analytical run is presented. The developed method employs an acidic background electrolyte with sodium polyanethol sulfonate (SPAS) as polyanionic electroosmotic flow (EOF) modifier to establish a strong cathodic EOF, sodium dodecyl sulfate (SDS) as pseudostationary selector, and acetonitrile and ethanol as organic modifiers. Separation of the analytes is based on two different mechanisms. The more basic analytes are protonated at the prevailing pH conditions and thus migrate in front of the cathodic EOF, whereas the less basic and neutral analytes interact with the SDS and are retained after the EOF. By optimizing electrolyte pH, the amount of solvents and SDS concentrations in the background electrolyte it is possible to completely separate all compounds of interest.

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DISCLAIMER This paper was submitted to the Bulletin of the World Health Organization and was posted to the COVID-19 open site, according to the protocol for public health emergencies for international concern as described in Vasee Moorthy et al. (http://dx.doi.org/10.2471/BLT.20.251561). The information herein is available for unrestricted use, distribution and reproduction in any medium, provided that the original work is properly cited as indicated by the Creative Commons Attribution 3.0 Intergovernmental Organizations licence (CC BY IGO 3.0).

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Abstract. Chen TV, Tuan ND, Triet NT, An NH, Nguyen PTT, Hai NTT, Nhi NTT, Co NQ, Nhi HTH, Huong HV, Phuong TTB, Nhung NTA. 2022. Morphological and molecular characterization of Distichochlamys citrea M.F. Newman in Bach Ma National Park, Thua Thien Hue Province, Vietnam. Biodiversitas 23: 2066-2079. Distichochlamys citrea (Black Ginger or gung den) is a medicinal plant endemic to Vietnam. However, this species is not easily identified due to the lack of a detailed description. Therefore, this study aimed to characterize morphological and molecular aspects of D. citrea from Bach Ma National Park, Vietnam. Six representative plants were selected for the following analyses. Macromorphological features were observed and compared with previous studies. The rhizomes, roots, petioles, and leaves were then histologically analyzed using iodine green-carmine staining. The ground rhizomes and leaves were also microscopically examined for powder characteristics. Finally, the D. citrea DNA barcode was amplified by Internal Transcribe Spacer (ITS) primers. Macromorphologically, D. citrea differs from other Distichochlamys species. Black Ginger, particularly, has elongated rhizomes (with scars from the shoots of previous years), green leaves, spread inflorescences, and yellow labellum (with deep slits). Additionally, D. citrea’s micromorphological structures (epidermis, exodermis, hypodermis, cortex, endodermis, and root pith) are similar to the genus Zingiber. However, the absence of calcium oxalate and silica crystals in the root is unique and can be used to distinguish this plant from other Zingiberaceae members. The sequenced amplicons (96.54% similar to Genbank's D. citrea ITS) demonstrated the ITS marker’s ability to identify Black Ginger.

Background. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic of pneumonia spreading around the world, leading to serious threats to public health and attracting enormous attention. There is an urgent need for sensitive diagnostic testing implementation to control and manage SARS-CoV-2 in public health laboratories. The quantitative reverse transcription PCR (RT-qPCR) assay is the gold standard method, but the sensitivity and specificity of SARS-CoV-2 testing are dependent on a number of factors. Methods. We synthesized RNA based on the genes published to estimate the concentration of inactivated virus samples in a biosafety level 3 laboratory. The limit of detection (LOD), linearity, accuracy, and precision were evaluated according to the bioanalytical method validation guidelines. Results. We found that the LOD reached around 3 copies/reaction. Furthermore, intra-assay precision, accuracy, and linearity met the accepted criterion with an RSD for copies of less than 25%, and linear regression met the accepted R 2 of 0.98. Conclusions. We suggest that synthesized RNA based on the database of the NCBI gene bank for estimating the concentration of inactivated virus samples provides a potential opportunity for reliable testing to diagnose coronavirus disease 2019 (COVID-19) as well as limit the spread of the disease. This method may be relatively quick and inexpensive, and it may be useful for developing countries during the pandemic era. In the long term, it is also applicable for evaluation, verification, validation, and external quality assessment.

The development of new drugs that combine active ingredients for the treatment hypertension is critically essential owing to its offering advantages for both patients and manufacturers. In this study, for the first time, detailed development of a scalable process of film-coated bi-layer tablets containing sustained-release metoprolol succinate and immediate-release amlodipine besylate in a batch size of 10,000 tablets is reported. The processing parameters of the manufacturing process during dry mixing-, drying-, dry mixing- completion stages were systematically investigated, and the evaluation of the film-coated bi-layer tablet properties was well established. The optimal preparation conditions for metoprolol succinate layer were 6 min- dry mixing with a high-speed mixer (120 rpm and 1400 rpm), 30-min drying with a fluid bed dryer, and 5-min- mixing completion at 25 rpm. For the preparation of amlodipine besylate layer, the optimal dry-mixing time using a cube mixer (25 rpm) was found to be 5 min. The average weight of metoprolol succinate layers and bi-layer tablets were controlled at 240–260 mg and 384–416 mg, respectively. Shewhart R chart and X¯ charts of all three sampling lots were satisfactory, confirming that the present scalable process was stable and successful. This study confirms that the manufacturing process is reproducible, robust; and it yields a consistent product that meets specifications.