Impurities in the active pharmaceutical ingredient rivastigmine tartrate were detected using a new high performance liquid chromatography (HPLC) method before being enriched and identified.
The new HPLC method detected six impurities in the API, marketed by Novartis for Alzheimer’s disease, of which three were unknown, researchers write in the Journal of Pharmaceutical and Biomedical Analysis.
Semi-preparative HPLC and LC/MS/MS (liquid chromatography tandem mass spectrometry) were used to enrich and identify the three unknown impurities. A number of other techniques were then used to confirm the proposed structures.
“Newly developed HPLC method was found to be simple, sensitive, selective, cost effective and stability indicating”, the researchers write, and as such could be used for routine studies.
A simplified route to enhancing drug stability is outlined by researchers writing in Proceedings of the National Academy of Sciences. The technique performs trifluoromethylation but without the metal catalysts, oxidants and temperatures associated with the process.
“I've been presenting this methodology at several pharma companies, and there's a lot of interest, so much so that their chemists are starting to use it”, Phil Baran, senior author of the study and Scripps research professor, said.
A cocktail of excipients and spray freeze drying has created antibiotic-loaded nanoparticles that could be inhaled to treat respiratory infections. Aggregates of 2-4µm are needed to deliver the treatment to the lungs. Once at the target the aggregates must be broken down by fluid of the lungs.
To develop nanoparticles with these characteristics researchers from Hwa Chong Institution and Nanyang Technological University, both in Singapore, investigated excipients and freeze drying.
Mannitol, leucine, polyvinyl alcohol (PVA), polyethylene glycol (PEG), lactose, trehalose and pluronic were all mixed with polycaprolactone (PCL) nanoparticles. A formulation of PCL:mannitol:leucine at a ratio of 1:6:1 was found to be most effective.