Solid Lipid Nanoparticles and Nanostructured Lipid Carriers as Topical Delivery Systems for Antioxidants
Andreia Ascenso, Sandra Simões, Helena Ribeiro in Carrier-Mediated Dermal Delivery, 2017
Thus, QC gathers a set of beneficial therapeutic effects along with a safety profile, which make it a very promising candidate for incorporation into topical formulations [109]. Additionally, it is also extensively metabolized by the gut microorganisms when administered orally, which reduces its absorption from the gastrointestinal tract and bioavailability [110,111]. However, despite it presents a suitable log P (log P = 1.82 ± 0.32 [112]) for cutaneous administration, its low aqueous solubility (0.55 μΜ [113]) limits its penetration to deeper skin layers [114]. One of the possibilities to enhance QC transport to/through the skin relies on the use of a carrier system, such as LN. This strategy was employed in a research work carried out by Bose et al. [109,115]. These authors have previously optimized the composition and production variables of a SLN formulation based on Compritol® 888 and a mixture of Tween 20/dioctyl sodium sulfosuccinate, manufactured via probe sonication. The in vitro release studies showed an initial burst release followed by prolonged release for up to 24 h. In turn, higher amounts of QC were localized within the skin, when compared to a control formulation containing particles in the micrometer range, thus demonstrating the feasibility of topical delivery of QC via a solvent-free solid lipid based nanosystem [115]. In a second study carried out by the same authors, the impact of other formulation factors, such as the inclusion of a liquid lipid (i.e., NLCs versus SLNs), and drug loading in the formulation previously optimized were investigated.
Introduction to bowel management
Victoria A. Lane, Richard J. Wood, Carlos A. Reck-Burneo, Marc A. Levitt in Pediatric Colorectal and Pelvic Surgery, 2017
As the name suggests, these medications soften the stool. Polyethylene glycol is an osmotic laxative, drawing water into the bowel lumen.Dioctyl sodium sulfosuccinate is an anionic detergent that has been shown to stimulate water and electrolyte secretion.Soft/mushy stool can be difficult to feel and empty. In anorectal malformation patients, stool softeners should not be used.
Nanosuspensions as Nanomedicine: Current Status and Future Prospects
Debarshi Kar Mahapatra, Sanjay Kumar Bharti in Medicinal Chemistry with Pharmaceutical Product Development, 2019
Common pharmaceutical excipients that are suitable for use as polymeric stabilizers include the cellulosics, such as hydroxypropyl cellulose (HPC) and hydroxypropylmethyl cellulose (HPMC), povidone (PVP K30), and pluronics (F68 and F127). The surfactant stabilizers can be non-ionic, such as polysorbate (Tween 80), or anionic, such as sodium laurylsulfate (SLS) and docusate sodium (DOSS). Cationic surfactants are typically not used as stabilizers for oral formulation due to their antiseptic properties [23].
Albendazole solution formulation via vesicle-to-micelle transition of phospholipid-surfactant aggregates
Published in Drug Development and Industrial Pharmacy, 2018
Zahari Vinarov, Gabriela Gancheva, Vladimir Katev, Slavka S. Tcholakova
In the previous section, we showed a dramatic increase of albendazole solubility in solutions of negatively charged surfactants at pH = 3. However, the surfactants with best effect (the alkylsulfates) have relatively high toxicity and are not appropriate for use as excipients in parenteral solutions. Thus, negatively charged amphiphiles with higher biocompatibility were identified and studied further with the aim to prepare albendazole solutions with low toxicity. The chosen materials were sodium dioctyl sulfosuccinate (AOT, sodium docusate) and a negatively charged phospholipid – sodium dipalmitoylphosphatidylglycerol (NaDPPG), both of which are approved for use in parenteral preparations [30]. Citrate buffer was used to keep pH = 3, which is required for sufficient albendazole ionization and solubilization, and is still in the range of pH values that are acceptable for parenteral administration [31,32].
Marine biofilm bacterial community response and carbon steel loss following Deepwater Horizon spill contaminant exposure
Published in Biofouling, 2019
Rachel L. Mugge, Jason S. Lee, Treva T. Brown, Leila J. Hamdan
CEWAF was prepared according to Forth et al. (2017). Briefly, 2 l of seawater were added to each of two, 2 l aspirator bottles and set on a stir plate at 200 RPM to create a 25% vortex. Macondo source oil (1.996 g) was added to the bottles using a gas-tight syringe. Stir plates were turned to 85 RPM and Corexit 9500A (17.3 µl in each) was added. Bottles were stirred for 18–24 h and then settled for 3–6 h. The resulting CEWAF was analyzed as above for PAHs and by liquid chromatography tandem mass spectrometry (LC – MS/MS) for dioctyl sodium sulfosuccinate (DOSS), a marker compound for Corexit 9500 residue. HEWAF and CEWAF stock solutions were stored in the cold room where microcosms were established for 1 h to allow fractions to acclimate to in situ conditions prior to addition. For oil and dispersed oil treatments, 80 ml of seawater were removed from each triplicate tank and replaced with 80 ml of HEWAF and CEWAF, respectively. The final concentration of oil in both oil and dispersed oil treatments was 5 mg l−1. The final concentration of Corexit 9500A in the dispersed oil treatments was 0.05 mg l−1.
Preclinical metabolism and disposition of an orally bioavailable macrocyclic FXIa inhibitor
Published in Xenobiotica, 2021
Silvi A. Chacko, Wu Yang, Yufeng Wang, Yuan Tian, Yang Hong, Michael Wallace, Bonnie Wang, William R. Ewing, Joseph M. Luettgen, Yue-Zhong Shu, Lisa J. Christopher
Plasma samples for metabolite profiling were obtained from separate TK studies where nonradiolabelled FXIa-6f was administered p.o. to rat (30 mg/kg), dog (20 mg/kg), and monkey (20 mg/kg). In these studies, FXIa-6f was prepared as a spray-dried dispersion over a polymer of hydroxypropyl methylcellulose acetate succinate and was formulated in a vehicle containing Methocel E4M and 0.02% docusate sodium in deionized water (0.5:0.02:99.48 w/w/w). Blood samples were collected at various times post dose into vacutainer tubes containing K2EDTA as anticoagulant. Plasma was prepared from blood by centrifugation, as described above, and stored at −20 °C until analysis. After the scheduled TK analyses for parent drug were complete, residual samples from available time points (i.e., 2 h for rat, 8 h for dog and monkey, n = 3 per time point) were analysed for metabolite profiles by LC-UV and LC-MS/MS analysis.
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