Study on the preparation and formation factors of frother emulsion

The Development of Dermal Self-Double-Emulsifying Drug Delivery Systems: Preformulation Studies as the Keys to Success

Self-emulsifying drug delivery systems (SEDDSs) are lipid-based systems that are superior to other lipid-based oral drug delivery systems in terms of providing drug protection against the gastrointestinal (GI) environment, inhibition of drug efflux as mediated by P-glycoprotein, enhanced lymphatic drug uptake, improved control over plasma concentration profiles of drugs, enhanced stability, and drug loading efficiency. Interest in dermal spontaneous emulsions has increased, given that systems have been reported to deliver drugs across mucus membranes, as well as the outermost layer of the skin into the underlying layers. The background and development of a double spontaneous emulsion incorporating four anti-tubercular drugs, clofazimine (CFZ), isoniazid (INH), pyrazinamide (PZY), and rifampicin (RIF), are described here. Our methods involved examination of oil miscibility, the construction of pseudoternary phase diagrams, the determination of self-emulsification performance and the emulsion stability index of primary emulsions (PEs), solubility, and isothermal micro calorimetry compatibility and examination of emulsions via microscopy. Overall, the potential of self-double-emulsifying drug delivery systems (SDEDDSs) as a dermal drug delivery vehicle is now demonstrated. The key to success here is the conduct of preformulation studies to enable the development of dermal SDEDDSs. To our knowledge, this work represents the first successful example of the production of SDEDDSs capable of incorporating four individual drugs.

Improving rhamnolipids production using fermentation-foam fractionation coupling system: cell immobilization and waste frying oil emulsion

This work focused on the development of an inexpensive carbon source and the improvement of the fermentation-foam fractionation coupling system. The rhamnolipids production capacity of waste frying oil (WFO) was evaluated. The suitable bacterial cultivation of seed liquid and the addition amount of WFO was 16 h and 2% (v/v), respectively. A combined strategy of cell immobilization and oil emulsion avoid cell entrainment inside foam and improves the oil mass transfer rate. The immobilization conditions of bacterial cells into alginate-chitosan-alginate (ACA) microcapsules were optimized using the response surface method (RSM). Under the optimal conditions, rhamnolipids production using batch fermentation with immobilized strain reached 7.18 ± 0.23% g/L. WFO was emulsified into a fermentation medium using rhamnolipids as emulsifier (0.5 g/L). By monitoring dissolved oxygen, 30 mL/min was selected as a suitable air volumetric flow rate for fermentation-foam fractionation coupling operation. The total production and recovery percentage of rhamnolipids were 11.29 ± 0.36 g/L and 95.62 ± 0.38%, respectively.

Probing the Coalescence Mechanism of Oil Droplets in Fluids Produced by Oil Wells and the Microscopic Interaction between Molecules in Oil Films

The microscopic interactions between oil droplets during the coalescence process have an important impact on the stability of the emulsion. In this paper, a model that can present the phenomenon of coalescence of oil droplets was established. Experiments were carried out to evaluate the stability of the emulsion. Combined with molecular dynamics simulation technology, the coalescence behaviors of emulsified oil droplets in fluids produced by oil wells were studied. Factors affecting the coalescence of emulsified oil droplets were analyzed. The results show that the fluid velocity was relatively high at the position where two oil droplets were close to each other. After the coalescence of oil droplets was completed, the emulsion system became stable. There was no obvious correlation between oil droplet size and coalescence time. When two adjacent oil droplets with different radii coalesced, the larger oil droplet moved a shorter distance overall. At the initial moment, there was a clear boundary between the oil film and the water phase. The longer the carbon chain, the more stable the emulsion. Among the following four crude oil molecules with the same number of carbon atoms, chain-like saturated hydrocarbons were the most stable, followed by chain-like carbon–carbon double bonds in component crude oil. Crude oils containing chain-like carbon–carbon triple bonds were the third most stable. Cyclane were the least stable. An increase in the asphaltene content was an important reason for the enhancement of the emulsifying ability and stability in the emulsion system. This work can help improve oil–water separation efficiency, thus reducing storage and transportation burden of crude oil.