Background The textural characteristics of fermented dairy products are important quality parameters that play a major role in their stability and consumer’s acceptance. The aim of this study was to investigate the influence of sodium caseinate, starch, lactose and lactic acid bacteria as ferment on the syneresis in a mixed model system, and to evaluate their impact on the acid gel formation throughout pH and zeta potential monitoring. Accordingly, a protocol was designed to perform an experimental design by using a mixture of the selected factors . Results A significant decrease of syneresis was detected in all mixtures at 8% of sodium caseinate, ranging between a minimum of 1.8% and a maximum of 20.6% compared to the mixtures at 3% of sodium caseinate in which the syneresis decrease had ranged between a minimum of 22.2% and a maximum of 47.8%. The addition of starch had a significant impact on the acidification profile and on the syneresis of the fermented mixed model. Moreover, the monitoring of pH and zeta potential during the lacto-fermentation process has also led to a better understanding of the acid gelation and the syneresis variations. Conclusion Syneresis varies very closely with sodium caseinate concentration, starch concentration and also with their association, regardless of the concentrations of lactose and ferment. In fact syneresis could be reduced to an optimum level if a sodium caseinate-starch mixed system is employed: Less syneresis gels could be obtained at a sodium caseinate concentration above 5% if starch is used above 1% .

Objective: The purpose of this study was to develop, optimize and characterize a stable microemulsion, with an improvement of the solubility of a poorly aqueous soluble drug, ibuprofen. Methods: Various oils (oleic acid, cottonseed oil, olive oil, argan oil, and labrafac® WL 1349), surfactants (tween® 80, tween® 40, tween® 20) and co-surfactants including polyethylene glycol 400, ethanol, 1-butanol, and propylene glycol were selected after solubility studies. Then, pseudo-ternary phase diagrams with surfactant/co-surfactant ratio of 1:2, 1:1, 2:1 and 3:1 were constructed and a D-optimal mixture design method was used to optimize the ibuprofen loaded microemulsion. The optimized microemulsion was evaluated for several characteristics including globule size, zeta potential, pH, conductivity, refractive index and stability studies. Results: Optimized microemulsion obtained was composed of oleic acid (6.88% w/w), tween® 80/1-butanol (3:1, 63.11% w/w) and water (30.00% w/w). The results obtained showed an average globule size of 117.5 nm, a zeta potential of-6.47 mV and a transmittance of 96.95±0.77%. The optimized formulation showed an improvement in the solubility of ibuprofen with unchanged characteristics for one month. Conclusion: The use of pseudo-ternary phase diagrams and mathematical modeling allows to obtain an optimal microemulsion with perfect stability for 1 mo and a better solubilization capacity of ibuprofen.

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The objective of this work is to (i) study the effect of variations in the proportions of four Macrogols on the pharmaco-technical characteristics of suppositories, (ii) define the optimal formula for a suppository with immediate effect; maximum disintegration and a minimum of hardness as defined in the European Pharmacopoeia. The lattice design mixture has been proposed as an optimization technique, the formulation factors are presented by the proportions of PEG 400 (X1), PEG 600 (X2), PEG 4000 (X3) and PEG 6000 (X4) and the response variables are (i) the disintegration time (Y1) (ii) the hardness (Y2). The second-degree empirical model was postulated to model the variations of the two response variables using the least-squares method.  The selected model explained about 67% and 84% of the variation for Y1 and Y2, respectively. All four factors had significant effects on the properties of the suppository. Interactions negatively affected both responses.  The numerical desirability method gave the following optimal formula: PEG400 (28.71334 %); PEG600 (24.23773%), PEG4000 (35.00944%) and PEG6000 (12.03949%) for a disintegration of 25.839 (+/-2.3) min and hardness =2147.321 (+/- 50) g.

The main purpose of this study is to improve and boost the solubility of Econazole Nitrate in water using phospholipid and surfactants, until it becomes possible to evaluate the utility of a mixture design in order to determine the optimal composition of non-ionic surfactants and phospholipids needed to obtain a significant improvement in the solubility of Econazole Nitrate in water. The design of experiments approach was tested using a mixture design of Lipoïd 75® as phospholipid and Econazole Nitrate, Tween® 80 and Solutol®HS 15 as surfactants,. Solubility was determined by the analysis of samples absorbance at 225 nm. and the measurement size of particles conducted using a Dynamic Light Scattering at the maximum point of solubility. The final results displayed an improvement in solubility with a statistically significant increase in many tested mixtures. Analysis of the design space showed that, the solubility of Econazole Nitrate is importantly affected by the concentration of surfactants. The best obtained test encloses 1% Econazole Nitrate, 2% Tween® 80, 0.5% Lipoid 75®, 2% Solutol®HS 15 and water q. s. for 100% w / w. Our study has demonstrated that optimized experimental design determines the proportions and the effects of every component based on a limited number of experiments.