Purpose: To find surfactants soluble in the two hydrofluoroalkane (HFA) propellants, HFA-134a and HFA-227ea; to compare surfactant solubility in the two propellants with those in 2H,3H-decafluoropentane (DFP) in order to assess latter's suitability as a liquid model propellant and to investigate surfactant aggregation and aggregate orientation in HFAs.
Methods: To assess surfactant solubility, HFA was added to a known amount of surfactant until dissolution was visibly apparent. An iodine solubilization method was used to determine surfactant aggregation behaviour in DFP. Fluorescence spectroscopic investigations on the surfactant orientation in aggregates were carried out in HFAs using a microviscosity sensitive fluorescent probe (1,3-dipyrenylpropane). The aim was to assess viscosity changes in the microenvironment of this lipophilic probe upon incorporation into surfactant aggregates.
Results: Soluble surfactants could be found among the polyoxyethylene-ethers and POE-PPO-block copolymer surfactants. Solubility in DFP appears to correlate with solubility in HFA-134a, but not HFA-227ea. Iodine solubilization indicates micellization of Brij 30 in DFP at a cmc (type II association behaviour). L-44 in DFP, on the other hand, does not exhibit a well defined cmc, but shows continuous surfactant aggregation (type I association behaviour). The fluorescence spectroscopic studies showed evidence for probe incorporation into surfactant aggregates in HFAs.
Conclusions: DFP proved to be a good model for HFA-134a only. An L1-aggregate orientation was shown for surfactants in HFAs and is in marked contrast to the chlorofluorocarbon propellant where a L2-aggregate orientation exists.
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http://dx.doi.org/10.1016/j.ijpharm.2005.01.027 | DOI Listing |
J Drug Target
January 2025
Department of Pharmaceutics, Sinhgad College of Pharmacy, Vadgaon (Bk.), Pune-411041, Maharashtra, India.
Ferulic acid (FA) is a phenolic compound obtained naturally and is a versatile antioxidant identified for its potential in managing hypertension. However, its application is constrained due to its classification as a BCS Class IV moiety. To address this, we concentrated on improving its solubility and permeability by developing nanostructured lipid carriers (NLCs) of FA using emulsification probe sonication technique.
View Article and Find Full Text PDFInt J Nanomedicine
January 2025
Department of Pharmaceutics, Faculty of Pharmacy, Northern Border University, Arar, Saudi Arabia.
Introduction: Rhein, a natural bioactive lipophilic compound with numerous pharmacological activities, faces limitations in clinical application due to poor aqueous solubility and low bioavailability. Thus, this study aimed to develop a rhein-loaded self-nano emulsifying drug delivery system (RL-SNEDDS) to improve solubility and bioavailability.
Methods: The RL-SNEDDS was prepared by aqueous titration method with eucalyptus oil (oil phase), tween 80 (surfactant), and PEG 400 (co-surfactant) and optimization was performed by 3 factorial design.
J Colloid Interface Sci
January 2025
Institute of Advanced Chemistry of Catalonia (IQAC), Consejo Superior de Investigaciones Científicas (CSIC), Jordi Girona, 18-26, 08034 Barcelona, Spain; Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN, ISCIII), Jordi Girona, 18-26, 08034 Barcelona, Spain. Electronic address:
AAPS PharmSciTech
January 2025
Consulting, Fort Collins, Colorado, USA.
Continuously explored in pharmaceuticals, microemulsions and nanoemulsions offer drug delivery opportunities that are too significant to ignore, namely safe delivery of clinically relevant drug doses across biological membranes. Their effectiveness as drug vehicles in mucosal and (trans)dermal delivery is evident from the volume of published literature. Commonly, their ability to enhance skin permeation is attributed to dispersion size, a characteristic closely related to solubilization capacity.
View Article and Find Full Text PDFLangmuir
January 2025
Unilever R&D, 40 Merrit Boulevard, Trumbull, Connecticut 06611, United States.
Mixtures of multiple surfactants that have superior performance to the individual components are highly sought-after commercially. Mixtures with a reduced Krafft point () are particularly useful as they enable applications at lower temperatures. Such an example is the soap maker's eutectic: the mixture of sodium laurate (NaL) and sodium oleate (NaOl).
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