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Investigating Colloidal Domains of Emulsion- and Gel-Type Formulations Using Neutron Scattering Techniques
Author Info
Mirzamani, Marzieh
ORCID® Identifier
http://orcid.org/0000-0003-3404-1137
Permalink:
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1623167085524348
Abstract Details
Year and Degree
2021, PhD, University of Cincinnati, Pharmacy: Pharmaceutical Sciences.
Abstract
Micellar, microemulsion, and gel systems are frequently used in personal care products to achieve the desired rheological, aesthetic, and cleansing properties. Surfactants are frequently used in these products and self-assemble with non-covalent interactions (e.g. hydrogen bonding, van der Waals forces) to form micellar systems and, when combined with oil and a co-surfactant, microemulsions. Gelators assemble into networks that trap solvent, making them excellent thickeners. Depending on the gelator’s molecular structure, the monomers can assemble covalently or, like surfactants, with non-covalent interactions. Systems that self-assemble via non-covalent interactions can be sensitive to various aspects of the formulation, such as the presence of salt, the ratio of solvent to surfactant or gel, and the solvent properties. Systematically studying the effects of various additives on the self-assembly of surfactants and gels is valuable to learn how to effectively tune the properties of these systems to maximize the release of actives and improve product performance. Sodium trideceth-2 sulfate and sodium laureth-1 and -3 sulfate were studied as individual primary surfactants while cocamidopropyl betaine was included as a cosurfactant to create three different mixed-surfactant systems. Dipropylene glycol (DPG, cosolvent) and two perfume mixtures consisting of 3 or 12 perfume raw materials (PRMs), spanning a range of log P values and molecular structures, were added to each mixed-surfactant system to study their effects on the surfactant self-assembly and release of perfumes into the headspace. The effect of dilution with water was also investigated to simulate rinse-off situations. Changes to the self-assemblies of two low-molecular weight gels (LMWGs) were studied as a function of gel concentration, the presence of carbamazepine, and sonication. Small-angle neutron scattering, gas-chromatography mass-spectrometry, nuclear magnetic resonance, microscopy, and statistics were used to study the geometry of the self-assemblies, release of perfume in the headspace, and the interactions between the monomers and localization of perfume. The surfactant tail structure in a formulation influences the localization of an active inside the self-assembly. The surfactant molecular structure and concentrations of perfume accord and DPG were key parameters influencing the geometry and size of the surfactant self-assembly. The headspace concentration for each PRM in the perfume accord was affected by the perfume accord composition, the PRM's log P value, the concentrations of other components like DPG in the system, the oil:water ratio in the system, the PRM's molecular structure, the surfactant tail structure and micelle dimensions and volume fraction. The perfume accord composition was important in the formation of Winsor IV type microemulsions and how much they can be diluted before they change type. For LMWG gel systems, the gelator concentration, the active ingredient concentration, the compatibility between the active’s molecular structure and the gelator’s, and the energy input into the system via sonication all influenced the speed at which the gel structure matured and the overall structure of the gel network. This further affected the rheological properties and strength of the bulk gel. Finally, suggestions on how to improve actives delivery and product effectiveness, and directions for future work in this field were provided.
Committee
Harshita Kumari (Committee Chair)
Kavssery Ananthapadmanabhan (Committee Member)
Thomas Beck, Ph.D. (Committee Member)
Kevin Li, Ph.D. (Committee Member)
Edward Smith, III (Committee Member)
Pages
364 p.
Subject Headings
Pharmaceuticals
Keywords
Soft Matter
;
Colloidal Chemistry
;
Surfactants
;
Low-molecular weight gels
;
Fragrance
;
Supramolecular Chemistry
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Refworks
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Citations
Mirzamani, M. (2021).
Investigating Colloidal Domains of Emulsion- and Gel-Type Formulations Using Neutron Scattering Techniques
[Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1623167085524348
APA Style (7th edition)
Mirzamani, Marzieh.
Investigating Colloidal Domains of Emulsion- and Gel-Type Formulations Using Neutron Scattering Techniques.
2021. University of Cincinnati, Doctoral dissertation.
OhioLINK Electronic Theses and Dissertations Center
, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1623167085524348.
MLA Style (8th edition)
Mirzamani, Marzieh. "Investigating Colloidal Domains of Emulsion- and Gel-Type Formulations Using Neutron Scattering Techniques." Doctoral dissertation, University of Cincinnati, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1623167085524348
Chicago Manual of Style (17th edition)
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Document number:
ucin1623167085524348
Download Count:
71
Copyright Info
© 2021, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.
Release 3.2.12