Co-Processed Excipients for Dispersible Tablets–Part 1: Manufacturability

Co-processed excipients may enhance functionality and reduce drawbacks of traditional excipients for the manufacture of tablets on a commercial scale. The following study aimed to characterise a range of co-processed excipients that may prove suitable for dispersible tablet formulations prepared by direct compression. Co-processed excipients were lubricated and compressed into 10.5-mm convex tablets using a Phoenix compaction simulator. Compression profiles were generated by varying the compression force applied to the formulation and the prepared tablets were characterised for hardness, friability, disintegration and fineness of dispersion. Our data indicates that CombiLac, F-Melt type C and SmartEx QD100 were the top 3 most suitable out of 16 co-processed excipients under the conditions evaluated. They exhibited good flow properties (Carr’s index ? 20), excellent tabletability (tensile strength >?3.0 MPa at 0.85 solid fraction), very low friability (<?1% after 15 min), rapid disintegration times (27–49 s) and produced dispersions of ideal fineness (<?250 μm). Other co-processed excipients (including F-Melt type M, Ludiflash, MicroceLac, Pharmaburst 500 and Avicel HFE-102) may be appropriate for dispersible tablets produced by direct compression providing the identified disintegration and dispersion risks were mitigated prior to commercialisation. This indicates that robust dispersible tablets which disintegrate rapidly could be manufactured from a range of co-processed excipients.     

REEVALUATION OF THE NITROGEN FIXATION BEHAVIOR IN THE MARINE NON‐HETEROCYSTOUS CYANOBACTERIUM LYNGBYA MAJUSCULA1

Lyngbya majuscula Harvey ex Gomont is a common marine cyanobacterium in tropical and subtropical near‐shore waters. A few reports have indicated that L. majuscula fixes nitrogen only in the light. Because this feature is uncommon among non‐heterocystous cyanobacteria, we attempted a reevaluation. Nitrogenase activity, regulation, and localization were examined over diel cycles on natural populations of L. majuscula growing in subtidal zones off Zanzibar in the western Indian Ocean. The data show that L. majuscula fixed nitrogen and synthesized nitrogenase in all cells during the dark phase of a diel cycle. During the light phase, nitrogenase was degraded to undetectable levels.     

The influence of exposure to immunosuppressive treatment during pregnancy on renal function and rate of apoptosis in native kidneys of female Wistar rats

Pregnancy puts a significant additional strain on kidneys. The aim of our study was to investigate the impact of immunosuppressive drugs on changes in native kidneys in female Wistar rats after exposure during pregnancy. The study was conducted on 32 dams, subjected to immunosuppressive regimens commonly used in the therapy of human kidney transplant recipients (cyclosporine A, mycophenolate mofetil and prednisone; tacrolimus, mycophenolate mofetil and prednisone; cyclosporine A, everolimus and prednisone). The animals received drugs for 2 weeks before pregnancy and during 3 weeks of pregnancy. In all treated dams lower body weight (but not kidney mass) and alterations in serum sodium and chloride ions were found; serum creatinine concentration was increased in dams treated with cyclosporine A, everolimus and prednisone. All treatment groups of dams showed increased apoptosis in the distal tubules. In histological examination the changed intensity of acidophilic or basophilic cytoplasm of epithelial cells was found in kidneys of rats treated with calcineurin inhibitors, mycophenolate mofetil and prednisone. All immunosuppressive regimens caused abnormalities affecting nephron tubules. Regimens containing calcineurin inhibitors and mycophenolate mofetil caused higher rate of apoptosis and more pronounced histopathological changes. Regimen based on everolimus despite the lower rate of apoptosis in the proximal tubules and lower accumulation of kidney injury markers revealed higher serum creatinine concentration. Thus, interpretation which combination of drugs is better or worse for long-lasting functioning of kidneys in pregnant females requires further studies.     

Two‐dimensional fluorescence as soft sensor in the monitoring of biotransformation performed by yeast

Soft sensors are powerful tools for bioprocess monitoring due to their ability to perform online, noninvasive measurement, and possibility of detection of multiple components in cultivation media, which in turn can provide tools for the quantification of more than one metabolite/substrate/product in real time. In this work, soft sensor based on excitation‐emission fluorescence is for the first time applied for the monitoring of biotransformation production of 2‐phenylethanol (2‐PE) by yeast strains. Main process parameters—such as optical density, glucose, and 2‐PE concentrations—were determined with high accuracy and precision by fluorescence fingerprinting coupled with partial least squares regression. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:299–307, 2017