Liquid paraffin

About: Liquid paraffin is a research topic. Over the lifetime, 6185 publications have been published within this topic receiving 52956 citations.

The self-bodying action of the mixed emulsifier cetrimide/ cetostearyl alcohol

Abstract: Liquid paraffin emulsions stabilized by the mixed emulsifier cetrimide/cetostearyl alcohol have been examined by microscopy, particle size analysis, continuous shear rheometry, and creep. The disperse phase of each emulsion was aggregated, and many of the nonspherical particles contained crystals of cetostearyl alcohol. The rheological properties of each emulsion were not related directly to the particle size distribution but to a gel network present in the continuous phase. This gel network was shown to be similar to that formed by dispersing cetrimide and cetostearyl alcohol in water so as to form a ternary system. All the systems showed complex flow properties in continuous shear experiments, e.g., hysteresis loops denoting irreversible shear breakdown. Additional complex flow properties, i.e., spur points and dilatancy, apparent in emulsions containing greater than 5% mixed emulsifier, were related to the structure in the continuous phase. In creep, mechanical models of three Voigt Units in series with a Maxwell Unit were deduced. In ternary systems and emulsions, the compliances decreased and the viscosities increased as the cetrimide/cetostearyl alcohol concetration increased. The creep parameters indicated that emulsions containing greater than 5% mixed emulsifier increased in consistency on aging, owing to the orientation of gel structure in the continuous phase.

The tribological behaviors of the polyurethane coating filled with nano-SiO2 under different lubrication conditions

Abstract: The tribological behaviors of polyurethane (PU) composite coatings filled with nano-SiO2 were investigated using a ring-on-block wear tester under different friction conditions, and the worn surfaces of nano-SiO2 filled PU coating and transfer films formed on the surface of the counterpart ring were investigated by scanning electron microscopy (SEM) and optical microscope (OM), respectively. The results show that the tribological behaviors of SiO2 filled PU coating are very sensitive to the formation of transferred films. The wear life of the SiO2 filled PU coating under water lubrication is the lowest and under liquid paraffin lubrication is the highest. The OM analyses indicated that a lubricating film can be more easily formed on the frictional surfaces under liquid paraffin lubrication; thus the lubrication condition at the rubbing surfaces can be greatly improved, leading to the decrease of the friction and wear of nano-SiO2 filled PU coating. However, water hinders the formation of transferred films and might penetrate and corrode the filler–matrix interface, which lead to the worst anti-wear property of nano-SiO2 filled PU coating.

Eudragit RS and RL (acrylic resins) microcapsules as pH insensitive and sustained release preparations of ketoprofen

Abstract: Microencapsulation of ketoprofen using Eudragit RS and RL (acrylic resins) was investigated based on the dispersion system of ketoprofen-containing acetone in liquid paraffin. Aluminium tristearate was used as an additive for the preparation of microcapsules. Good reproducibility was observed in the microencapsulation and the resulting microcapsules were uniform, free-flowing particles. The phase diagram of ketoprofen-Eudragit RS or RL-aluminium tristearate indicated that it is only in a very limited region that spherical microcapsules ranging from 250 to 1000 microns in diameter could be prepared. Instrumental analysis using an energy dispersive-type X-ray microanalyser and a scanning electron microscope showed that aluminium tristearate was localized near the surface of the microcapsules. From these results, it was presumed that aluminium tristearate reduces the phase tension between Eudragit microcapsules and liquid paraffin. The dissolution patterns of ketoprofen from Eudragit RS and RL microcapsules were independent of the pH of the dissolution medium, and the dissolution rates were considerably lower than those from ketoprofen powders.

A comparative study: the efficacy of liquid paraffin and lactulose in management of chronic functional constipation.

Abstract: Objectives: To determine and compare efficacy, safety and optimal dose of two laxatives, liquid paraffin and lactulose, in 40 children with chronic functional constipation Methods: A total of 20 children were treated with liquid paraffin and 20 with lactulose for 8 weeks and at an initial dose of 1 mL/kg per day for both drugs The dose was adjusted every 3 days as required and a diary was kept to monitor dose, side-effects, stool frequency and consistency, and other symptoms Results: During first 4 weeks, improvement in stool consistency and frequency was significantly higher in liquid the paraffin group (P < 001 and P < 005, respectively) Improvement in the number of stools per week was also significantly higher in the liquid paraffin group during the last 4 weeks of therapy (P < 005) Compliance rates averaged 95% in the liquid paraffin group and 90% in the lactulose group during the first 4 weeks of therapy and 90% in the liquid paraffin group and 60% in the lactulose group during the last 4 weeks of therapy (χ2 = 48, SD = 1, P = 002) During the first 4 weeks of therapy and during the last 4 weeks of therapy, mostly side-effects and poor symptom control, respectively, influenced the compliance in the liquid paraffin group Conclusions: Liquid paraffin is more effective in the treatment of children with constipation Patients treated with liquid paraffin responded more rapidly than patients responding to lactulose and showed fewer side-effect It is considered that late response and side-effects in conjunction with poor symptom control influence the patient compliance and the successful treatment of childhood constipation