Conventional Sterilization Methods Research Articles

New generation of poly(ortho esters): synthesis, characterization, kinetics, sterilization and biocompatibility

After a brief historical overview of the development of three families of poly(ortho esters) (POEs), the physico-chemical characteristics, drug release properties and biocompatibility of the third generation is discussed. Its synthesis is based on a transesterification reaction between 1,2,6-hexanetriol and trimethylorthoacetate. This viscous hydrophobic polymer has been used for the sustained release of 5-fluorouracil (5-FU) or mitomycin C (MMC) in glaucoma filtering surgery. It shows a good correlation between drug release and polymer erosion and can be injected using a hydraulic syringe. Drug release can be modulated by using different molecular weights of the polymer, or by adding basic or acidic excipients. Because conventional sterilization methods using gamma or electron beam-irradiation can not be used due to changes in molecular weight and dynamic viscosity resulting from backbone cleavage, an aseptic fabrication procedure has been developed and validated. POE biocompatibility has been established after subconjunctival injections of POE, monomers and degradation products in rabbits. Better control of the microenvironmental pH during polymer degradation has been achieved by using an in situ formed buffer system.

Observations on the Effect of Sunlight on the Horse and Cow

The quality and safety of food products are the two factors that most influence the choices made by today's increasingly demanding consumers. Conventional food sterilization and preservation methods often result in a reduction in the apparent freshness and quality of the final products. High pressure processing is a relatively new non-thermal food processing method that subjects liquid or solid foods, with or without packaging, to pressures between 50 and 1000 MPa. Extensive investigations have revealed the potential benefits of high pressure processing as an alternative to traditional heat treatments. These benefits are apparent in various areas of food processing, such as the inactivation of microorganisms and enzymes, denaturation and alteration of the functionality of proteins, and structural changes to food materials. Moreover, high pressure can be used to enhance several processing operations, such as freezing, thawing and extraction, thus providing new processing options.