Synthesis and characterization of osmotic pump capsules containing polyoxyethylene and pH modifier to control the release of nifedipine.

The aim of this study was to formulate osmotic pump capsules (OPCs) to control the release of nifedipine (NP). NP solid dispersion was prepared by solvent evaporation method. The prepared mixture of NP solid dispersion and various excipients were filled into the commercial HPMC hard capsule shells and then coated with cellulose acetate (CA) solution to form NP-OPC. The CA coating solution consisted of CA as semi-permeable membrane, and Poloxamer 188 as pore formers. The impact of addition agents, citric acid and pore formers on in vitro drug release were investigated. Furthermore, the study has highlighted the impact of paddle speed and the pH value of release media, on the release and compared the release with the commercial controlled release tablets. The in vitro drug release study indicated that drug release could reach 95% in 24 h with optimal formulation, and interestingly model fitting showed that the drug release behavior was closely followed to zero-order release kinetics. The pharmacokinetic studies were performed in rabbits with commercial controlled release tablets as reference, both preparations showed a sustained release effect. Compared with traditional preparation methods of OPCs, the new preparation process was simplified without the operation of laser drilling and the sealing process of capsule body and cap, which improved the feasibility of industrial production.

Nanoemulsion-based delivery approaches for nutraceuticals: fabrication, application, characterization, biological fate, potential toxicity and future trends.

In the modern food industry, people are paying more and more attention to the use of edible nanoemulsions to encapsulate, protect and deliver lipophilic functional ingredients, such as volatile additives, polyphenols, aromas, pigments, proteins, vitamins, oil-soluble flavors, preservatives, etc., which are the current global needs. Nanoemulsions are constructed with droplets of nano range size and they offer many potential advantages over conventional emulsions including the delivery of both hydrophilic and hydrophobic compounds, higher stability, better antibacterial properties, good taste experience, higher affinity, longer shelf-life and improvement of the bioavailability of components. Moreover, they are highly capable of improving the wettability and/or solubility of poorly water-soluble compounds, which may result in better pharmacokinetic and pharmacodynamic properties of nutraceutical compounds. On the other hand, oral nanoemulsions also have certain risks, such as their ability to change the biological fate of biologically active ingredients in the gastrointestinal tract and the potential toxicity of certain ingredients used in their production. This review article summarizes the manufacturing, application, characterization, biological fate, potential toxicity, and future challenges and trends of nanoemulsions, and focuses on nanoemulsion-based nutraceutical delivery approaches suitable for the food industry.