ABSTRACT
Reverse micelles extraction of erythromycin and amoxicillin were carried out using the novel Sophorolipids biosurfactant. By replacing commonly used chemical surfactants with biosurfactant, reverse micelle extraction can be further improved in terms of environmental friendliness and sustainability. A central composite experimental design was used to investigate the effects of solution pH, KCl concentration, and sophorolipids concentration on the reverse micelle extraction of antibiotics. The most significant factor identified during the reverse micelle extraction of both antibiotics is the pH of aqueous solutions. Best forward extraction performance for erythromycin was found at feed phase pH of approximately 8.0 with low KCl and sophorolipids concentrations. Optimum recovery of erythromycin was obtained at stripping phase pH around 10.0 and with low KCl concentration. On the other hand, best forward extraction performance for amoxicillin was found at feed phase pH around 3.5 with low KCl concentration and high sophorolipids concentration. Optimum recovery of erythromycin was obtained at stripping phase pH around 6.0 with low KCl concentration. Both erythromycin and amoxicillin were found to be very sensitive toaqueous phase pH and can be easily degraded outside of their stable pH ranges.
Subject(s)
Anti-Bacterial Agents/chemistry , Liquid-Liquid Extraction/methods , Micelles , Oleic Acids/chemistry , Surface-Active Agents/chemistry , Amoxicillin/chemistry , Amoxicillin/isolation & purification , Anti-Bacterial Agents/isolation & purification , Erythromycin/chemistry , Erythromycin/isolation & purification , Hydrogen-Ion Concentration , Osmolar Concentration , Potassium Chloride/chemistry , Water/chemistryABSTRACT
In clinical studies, drugs with hydrophobic characteristic usually reflect low bioavailability, poor drug absorption, and inability to achieve the therapeutic concentration in blood. The production of poor solubility drugs, in abundance, by pharmaceutical industries calls for an urgent need to find the alternatives for resolving the above mentioned shortcomings. Poor water solubility drugs loaded with polymeric micelle seem to be the best alternative to enhance drugs solubility and bioavailability. Polymeric micelle, formed by self-assembled of amphiphilic block copolymers in aqueous environment, functioned as solubilizing agent for hydrophobic drug. This review discusses the fundamentals of polymeric micelle as drug carrier through representative literature, and demonstrates some applications in various clinical trials. The structure, characteristic, and formation of polymeric micelle have been discussed firstly. Next, this manuscript focuses on the potential of polymeric micelles as drug vehicle in oral, transdermal routes, and anti-cancer agent. Several results from previous studies have been reproduced in this review in order to prove the efficacy of the micelles in delivering hydrophobic drugs. Lastly, future strategies to broaden the application of polymeric micelles in pharmaceutical industries have been highlighted.
Subject(s)
Drug Delivery Systems , Micelles , Nanostructures/chemistry , Polymers/chemistry , Antineoplastic Agents/administration & dosage , HumansABSTRACT
OBJECTIVE: To determine the prevalence of smoking among medical students at the medical college at King Fahad Medical City in Riyadh, and assess the association between smoking and socio-demographical factors, smoking contacts, reasons for smoking and attempts to quit. MATERIALS AND METHODS: Cross-sectional survey in which anonymous, self-administered questionnaire was used to survey the cigarette smoking habits of the first- and second-year medical students in the Faculty of Medicine, King Fahad Medical City in June 2009. RESULTS: Overall 39.8 % of the investigated students (153) had smoked before, and 17.6% were current smokers. The mean age of initiating smoking was 15.8 (±3.3). There were significantly more males than females. The most important reasons for smoking were leisure, imitation of other people and a means of relieving psychological pressure. Reasons for not smoking were mostly health and religion-based. Smokers tended to have friends who smoked. CONCLUSION: Cigarettes smoking is highly prevalent among medical students in the Faculty of Medicine, King Fahad Medical City. Contact with smokers particularly friends are the major risk factors for the initiation of the habit. Health and religious considerations are important motives for not smoking, quitting or attempting to quit. These findings can be of help in designing future intervention strategies.
