Use Of Solubilization Research Articles

Study on the Mechanism of Carbon Dioxide Miscible Fracturing Fluid Huff and Puff in Enhanced Oil Recovery

Carbon dioxide (CO2) miscible fracturing huff-and-puff technology now plays a pivotal role in enhancing crude oil recovery rates, particularly in reservoirs with challenging physical properties, strong water sensitivity, high injection pressure, and complex water-injection dynamics. In this study, the oil-increasing mechanism and huff-and-puff effect of CO2 miscible fracturing fluid are investigated through a comprehensive experimental approach. Specifically, experiments on PVT gas injection expansion, minimum miscible pressure, and CO2 miscible fracturing fluid huff and puff are conducted on the G fault block reservoir of the J Oilfield. The experimental findings demonstrate that injecting CO2 into reservoirs leads to an expansion in oil volume, a reduction in viscosity, and an increase in saturation pressure. Crude oil extraction is further enhanced by the addition of solubilizers and viscosity reducers. The use of solubilizers not only increases oil recovery rates but also reduces the minimum miscible pressure required for effective CO2 dispersion. We also found that shut-in times, permeability, and the huff-and-puff method used all have considerable impacts on huff-and-puff recovery rates. This study offers valuable technical insights, supporting the application of CO2 miscible fracturing huff-and-puff technology to enhance oil recovery rates in low-permeability reservoirs.

Enhanced triclosan biodegradation by a biphasic bioreactor

Triclosan (TCS), an antiseptic agent that facilitates the formation of microbial resistances, has been widely used and is therefore ubiquitously detectable in wastewater. However, structure and low water solubility limit both microbial transformation kinetic and removal efficiency of TCS. Therefore, the use of solubilizers or non-aqueous phases (NAP) appears to be a suitable approach for rapid, complete, and cost-effective treatment of highly contaminated TCS point sources such as sports clubs, hospitals, industrial wastewater treatment plants or synthesis effluents without dilution effects.The mixed culture TCSmix100 previously isolated and characterized, and able to completely mineralize TCS at stoichiometric chloride release, was investigated in presence or absence of solubilizers in lab-scale well stirred batch reactors. While TCS conversion was limited in solubilizer-free tests due to limited solubility of TCS crystals within the aqueous phase, solubilizers enhanced water solubility, mass transport and microbial kinetics. Thus, TCS transformation rate at initial 1.45 g TCS L−1 was further increased from a high level of 155–172 mg L−1d−1 without solubilizers to 399 mg L−1d−1 or to 888 mg L−1 d-1 providing β-pinene or α-pinene as NAPs, i.e., by a factor of 2.3–5.2, exceeding kinetic parameters of other strains described in literature by at least two orders of magnitude. These results clearly demonstrate the high TCS mineralization capacity of this biphasic treatment technologies and its applicability in treatment of highly contaminated TCS point-sources to eliminate recalcitrant contaminants at high levels before getting diluted.

Strategies to Improve Drug Strength in Nasal Preparations for Brain Delivery of Low Aqueous Solubility Drugs.

Intranasal administration is a promising route for brain drug delivery. However, it can be difficult to formulate drugs that have low water solubility into high strength intranasal solutions. Hence, the purpose of this work was to review the strategies that have been used to increase drug strength in intranasal liquid formulations. Three main groups of strategies are: the use of solubilizers (change in pH, complexation and the use cosolvents/surfactants); incorporation of the drugs into a carrier nanosystem; modifications of the molecules themselves (use of salts or hydrophilic prodrugs). The use of high amounts of cosolvents and/or surfactants and pH decrease below 4 usually lead to local adverse effects, such as nasal and upper respiratory tract irritation. Cyclodextrins and (many) different carrier nanosystems, on the other hand, could be safer for intranasal administration at reasonably high concentrations, depending on selected excipients and their dose. While added attributes such as enhanced permeation, sustained delivery, or increased direct brain transport could be achieved, a great effort of optimization will be required. On the other hand, hydrophilic prodrugs, whether co-administered with a converting enzyme or not, can be used at very high concentrations, and have resulted in a fast prodrug to parent drug conversion and led to high brain drug levels. Nevertheless, the choice of which strategy to use will always depend on the characteristics of the drug and must be a case-by-case approach.

Use of solubilizers in preclinical formulations: Effect of Cremophor EL on the pharmacokinetic properties on early discovery compounds

The aim of the present study was to determine whether Cremophor EL is a suitable surfactant that can be routinely applied to pharmacokinetic (PK) studies in early drug discovery without influencing the intrinsic PK characteristics of the new chemical entities (NCEs). Cremophor EL, a polyoxyl 35 castor oil, has been used as a solubilization aid for water-insoluble compounds in pre-clinical drug discovery. The effect of Cremophor EL on the PK properties of NCEs was examined in seven structurally diverse discovery compounds after intravenous administration. Significant effects of Cremophor EL on plasma volume of distribution (Vss) and plasma clearance (CL) were observed in compounds with moderate to high Vss or CL. The plasma Vss decreased more than 2-fold and the Vss binning category decreased by one unit (e.g. from moderate to low Vss) in 6 of 7 test compounds. Two to five-fold reduction of CL was observed with these 6 compounds. Effect on the terminal half-life (T1/2) was minimal. Using one of these 7 NCEs, concentration dependent effect of Cremophor EL in the vehicle was also determined. Higher percentage of Cremophor EL in vehicle resulted in progressively increased alterations on the plasma CL and Vss. Taken together, these findings indicated that Cremophor EL altered the intrinsic PK properties of these discovery compounds in a concentration dependent manner.

Enhancement of Bioavailability of Fenofibrate with Alpha Tocopherol and Phospholipids as Solubilizers

The purpose of this study was to investigate the effect of different solubilizers namely alpha tocopherol, soyphosphatidylcholine 70, Phospholipon 80H, and Phospholipon 90H on the bioavailability of sustained release fenofi-brate pellets using fluid bed coating by applying Taguchi design to optimize the type and concentration of solubilizer at four levels namely 0.5%, 1%, 1.5%, and 2%. The pellets were prepared by loading the fenofibrate blended with other excipients onto the core sugar pellets with the aid of the binder solution. Taguchi experimental runs with alphatocopherol 1% and Phospholipon 90H 2% (test) showed significant differences in in vitro dissolution behavior of drug compared to the pure drug. The pharmacokinetics of pure drug and test was evaluated in healthy male Wistar rats and found that t1/2 was reduced significantly (4.36 and 4.02 hours) while AUC0-t (32.14 ± 6.38 μg h/ml, 36.94 ± 6.2 μgh/ml), Cmax (8.7 ± 2.31 μg/ml, 9.8 ± 2.2 μg/ml) were improved markedly compared to the pure drug with t1/2 (7.339314± 3.1 hours), AUC0-t (11.89 ± 8.13 μg h/ml), and Cmax (5.137 ± 3.37 μg/ml). The extent of the mean plasma exposure of fenofibrate was 2.7 and 3.1 fold higher in animals treated with test. The ANOVA results revealed that type and concentration of solubilizer are crucial for enhancement of in vitro dissolution profile. Hence use of solubilizers may be the promising way to improve the oral bioavailability of fenofibrate.

Properties of Fulvic Acid Extracted from Excess Sludge and Its Inhibiting Effect on β-Hexosaminidase Release

The physicochemical and biological properties of fulvic acid extracted and purified from excess sludge and solubilized excess sludge were studied. Solubilization was introduced to improve the recovery rate of fulvic acid from the sludge. The structural features of fulvic acid from excess sludge and solubilized excess sludge were characterized by using an elemental analysis, Fourier transform infrared spectroscopy and (1)H-nuclear magnetic resonance spectroscopy, and were compared with fulvic acid extracted from peat which had an inhibitory effect on the type I allergy in our previous study. The results show that they had a higher aliphatic characteristic with lower oxygen group content than fulvic acid from peat, and that the aliphatic characteristic was further strengthened by the use of solubilization. The biological properties of fulvic acid from excess sludge and solubilized excess sludge showed an inhibitory effect on beta-hexosaminidase release at the antigen-antibody binding stage and antigen-receptor binding stage by using rat basophilic leukemia cells.

Computational prediction of solubilizers’ effect on partitioning

A computational model for the prediction of solubilizers’ effect on drug partitioning has been developed. Membrane/water partitioning was evaluated by means of immobilized artificial membrane (IAM) chromatography. Four solubilizers were used to alter the partitioning in the IAM column. Two types of molecular descriptors were calculated: 2D descriptors using the MOE software and 3D descriptors using the Volsurf software. Structure–property relationships between each of the two types of descriptors and partitioning were established using partial least squares, projection to latent structures (PLS) statistics. Statistically significant relationships between the molecular descriptors and the IAM data were identified. Based on the 2D descriptors structure–property relationships R 2 Y = 0. 99 and Q 2 = 0.82–0.83 were obtained for some of the solubilizers. The most important descriptor was related to log P. For the Volsurf 3D descriptors models with R 2 Y = 0.53–0.64 and Q 2 = 0.40–0.54 were obtained using five descriptors. The present study showed that it is possible to predict partitioning of substances in an artificial phospholipid membrane, with or without the use of solubilizers.

Oral Dosage form Design and its Influence on Dissolution Rates for a Series of Drugs

The study illustrates the influence oral dosage form design has on dissolution rates for drugs from different chemical and pharmacological classes. Comparative data demonstrate that relatively insoluble drugs, when formulated in soft elastic capsules, are released faster than from commercially available tablets. Faster dissolution from soft elastic capsules is believed to be due to the more rapid dispersion of the active ingredients. Rapid dispersion of medicaments is enhanced by the use of solubilizers and/or surfactants in the formulation design. Soft elastic capsules are recommended for the formulation of low-dose medications, of relatively insoluble drugs, and of drugs where early high-blood level of the drug is indicated.