Piramal (United Kingdom)

Objective: In this study, PEGylated rosin derivatives (PRDs) namely D1 and D2 were synthesized and evaluated for their application to produce sustained-release antibacterial films containing sparfloxacin for periodontitis.Significance: PRDs are biodegradable and biocompatible, and therefore sustained-release dental implant of PRD-sparfloxacin can provide an effectual treatment for periodontitis.Methods: Films were produced by solvent casting technique and characterized for morphology, swelling-index, in vitro degradation and drug release kinetics. The impact of type of PRD, concentration of PRDs, and addition of plasticizer (dibutyl phthalate) on various film properties was evaluated. The films were also subjected to stability study at 30 °C and 40 °C for 90 days.Results: Both D1 and D2 produced smooth and non-porous films with sparfloxacin. The D1 films, due to lower amount of polyethylene glycol 400 in D1, exhibited lower swelling-index, slower degradation, and slower drug release compared to D2 films. An increase in PRDs concentration decreased swelling-index, prolonged degradation time, and decreased drug release rate of films; addition of plasticizer showed the similar effect. At pH 7.6, D1 and D2 films showed complete degradation at the end of 58 and 51 days, respectively. At the end of 21 days, D1 and D2 films released 41.85% and 61.53% sparfloxacin, respectively. The drug release from D1 films followed Higuchi square-root kinetics, while D2 films released drug by the zero order kinetics. The stability conditions did not significantly alter PRDs-film properties.Conclusion: Results revealed that PRDs can be used successfully to produce sustained-release antibacterial films containing sparfloxacin for the treatment of periodontitis.

Biotransformations on larger scale are mostly limited to cases in which alternative chemical routes lack sufficient chemo-, regio-, or stereoselectivity. Here, we expand the applicability of biocatalysis by combining cheap whole cell catalysts with a microaqueous solvent system. Compared to aqueous systems, this permits manifoldly higher concentrations of hydrophobic substrates while maintaining stereoselectivity. We apply these methods to four different two-step reactions of carboligation and oxidoreduction to obtain 1-phenylpropane-1,2-diol (PPD), a versatile building block for pharmaceuticals, starting from inexpensive aldehyde substrates. By a modular combination of two carboligases and two alcohol dehydrogenases, all four stereoisomers of PPD can be produced in a flexible way. After thorough optimization of each two-step reaction, the resulting processes enabled up to 63 g L–1 product concentration (98% yield), space-time-yields up to 144 g L–1 d–1, and a target isomer content of at least 95%. Despite the use of whole cell catalysts, we did not observe any side product formation of note. In addition, we prove that, by using 1,5-pentandiol as a smart cosubstrate, a very advantageous cofactor regeneration system could be applied.