Formulation and characterization of liquid crystal systems containing azelaic acid for topical delivery.

Drug Dev Ind Pharm

Department of Pharmaceutical Technology, Hacettepe University, Faculty of Pharmacy, Ankara, Turkey.

Published: February 2013

Purpose: The aim of this study is to prepare and characterize azelaic acid (AzA) containing liquid crystal (LC) drug delivery systems for topical use.

Methods: Two ternary phase diagrams, containing liquid paraffin as the oil component and a mixture of two nonionic surfactants (Brij 721P and Brij 72), were constructed. Formulations chosen from the phase diagrams were characterized by polarized light microscopy, rheological analyses, differential scanning calorimetry (DSC), and small angle x-ray scattering spectroscopy.

Results: Polarized light microscopy proved that except the oil/water emulsion (O/W E), other formulations showed lamellar LC structure. In vitro release studies indicated that the fastest release was achieved by the Lamellar LC (LLC) and O/W E systems, whereas slower release was obtained from the emulsion containing lamellar LC (E-LLC) and distorted lamellar LC (D-LLC) systems. Results of rheological measurements both supported the results of in vitro release studies and showed that the emulsion containing the LC (E-LLC) system had the most stable structure. The formulations and their effect on stratum corneum (SC) were evaluated by DSC studies. The lamellar LC (LLC), emulsion containing lamellar liquid crystal (E-LLC), and O/W E formulations had an effect on both lipid and protein components of SC, whereas distorted lamellar liquid crystal (D-LLC) system had an effect on only the lipid components of SC.

Conclusions: LLC systems could be considered promising for the topical delivery of AzA.

Download full-text PDF

Source
http://dx.doi.org/10.3109/03639045.2012.671829DOI Listing

Publication Analysis

Top Keywords

liquid crystal
16
azelaic acid
8
topical delivery
8
phase diagrams
8
polarized light
8
light microscopy
8
o/w formulations
8
vitro release
8
release studies
8
lamellar llc
8

Similar Publications

The purpose of this study was to improve the quality of frozen-thawed canine spermatozoa through the optimization of glycerol concentration (GC) and freezing rate in the semen freezing protocol. Ejaculates from nine dogs were diluted with an extender containing 0%, 1.5%, 3%, 6%, or 9% glycerol.

View Article and Find Full Text PDF

Non-ionic surfactant self-assembly in calcium nitrate tetrahydrate and related salts.

Soft Matter

January 2025

School of Chemistry and University of Sydney Nano Institute, The University of Sydney, Sydney, NSW, 2006, Australia.

Self-assembly of amphiphilic molecules can take place in extremely concentrated salt solutions, such as inorganic molten salt hydrates or hydrous melts. The intermolecular interactions governing the organization of amphiphilic molecules under such extreme conditions are not yet fully understood. In this study, we investigated the specific effects of ions on the self-assembly of the non-ionic surfactant CH(OCHCH)OH (CE) under extreme salt concentrations, using calcium nitrate tetrahydrate as a reference.

View Article and Find Full Text PDF

Halogen-Bearing Peptide Liquid Crystals to Elicit Molecular Alignments for Residual Dipolar Coupling Measurement.

Macromol Rapid Commun

January 2025

State Key Laboratory of Applied Organic Chemistry, Lanzhou Magnetic Resonance Center, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China.

Residual dipolar coupling (RDC) not only contributes to the dynamic analysis of proteins but also provides a robust route for the structure determination of small organic compounds. An essential prerequisite for this methodology is the availability of alignment media. Herein, a series of novel peptide-based alignment media are generated by introducing D-type or halogen-bearing amino acids for RDC measurements.

View Article and Find Full Text PDF

Liquid crystal torons in Poiseuille-like flows.

Sci Rep

January 2025

Centro de Física Teórica e Computacional, Faculdade de Ciências, Universidade de Lisboa, 1749-016, Lisboa, Portugal.

Three-dimensional (3D) simulations of the structure of liquid crystal (LC) torons, topologically protected distortions of the LC director field, under material flows are rare but essential in microfluidic applications. Here, we show that torons adopt a steady-state configuration at low flow velocity before disintegrating at higher velocities, in line with experimental results. Furthermore, we show that under partial slip conditions at the boundaries, the flow induces a reversible elongation of the torons, also consistent with the experimental observations.

View Article and Find Full Text PDF

Review of honeycomb-based Kitaev materials with zigzag magnetic ordering.

Acta Crystallogr B Struct Sci Cryst Eng Mater

February 2025

Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.

The search for a Kitaev quantum spin liquid in crystalline magnetic materials has fueled intense interest in the two-dimensional honeycomb systems. Many promising candidate Kitaev systems are characterized by a long-range-ordered magnetic structure with an antiferromagnetic zigzag-type order, where the static moments form alternating ferromagnetic chains. Recent experiments on high-quality single crystals uncovered the existence of intriguing multi-k magnetic structures, which evolved from zigzag structures.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!