Thermal, electrical, and mechanical properties of tween 80/span 80-based organogels and its application in iontophoretic drug delivery

Organogels: "GelVolution" in Topical Drug Delivery - Present and Beyond

Topical drug delivery holds immense significance in dermatological treatments due to its non-invasive nature and direct application to the target site. Organogels, a promising class of topical drug delivery systems, have acquired substantial attention for enhancing drug delivery efficiency. This review article aims to explore the advantages of organogels, including enhanced drug solubility, controlled release, improved skin penetration, non-greasy formulations, and ease of application. The mechanism of organogel permeation into the skin is discussed, along with formulation strategies, which encompass the selection of gelling agents, cogelling agents, and additives while considering the influence of temperature and pH on gel formation. Various types of organogelators and organogels and their properties, such as viscoelasticity, non-birefringence, thermal stability, and optical clarity, are presented. Moreover, the biomedical applications of organogels in targeting skin cancer, anti-inflammatory drug delivery, and antifungal drug delivery are discussed. Characterization parameters, biocompatibility, safety considerations, and future directions in optimizing skin permeation, ensuring long-term stability, addressing regulatory challenges, and exploring potential combination therapies are thoroughly examined. Overall, this review highlights the immense potential of organogels in redefining topical drug delivery and their significant impact on the field of dermatological treatments, thus paving the way for exciting prospects in the domain.

Graphene Oxide Increases Corneal Permeation of Ciprofloxacin Hydrochloride from Oleogels: A Study with Cocoa Butter-Based Oleogels

In this work, oleogels of cocoa butter (CB), rice bran oil (RBO), and graphene oxide (GO) were prepared. The prepared oleogels were subjected to various characterization techniques such as bright-field microscopy, X-ray diffraction (XRD), crystallization kinetics, differential scanning calorimetry (DSC), and mechanical studies. The influence of increasing GO content on the in vitro drug release and ex vivo corneal permeation of the model drug (ciprofloxacin HCl-CPH) from the oleogels was also investigated. Bright-field micrographs showed that increment in GO content reduced the size of the globular particles of CB. XRD analysis revealed that CB was crystallized in its β' and β polymorphic forms in the oleogels, which was in agreement with thermal studies. The mechanical characterization demonstrated that the presence of GO improved the elastic nature and stress-bearing properties of the oleogels. Moreover, GO altered the crystallization kinetics of CB in the oleogels in a composition-dependent manner. The in vitro release of CPH from the oleogels occurred through either Fickian diffusion or fat network relaxation or a combination thereof. Furthermore, the inclusion of GO enhanced the ex vivo permeation of CPH molecules across the caprine cornea. Hence, we concluded that the prepared oleogels could be explored as potential delivery systems for ophthalmic applications.

Transdermal Delivery of Gold Nanoparticles by a Soybean Oil-Based Oleogel under Iontophoresis

Developing a facile mechanism for transporting nanoparticles across the whole skin by overcoming the stratum corneum is a challenging task. Herein, a stimuli-responsive and noninvasive transport of gold nanoparticles (AuNPs) has been reported through the fabrication of AuNP-incorporated soybean oil-based oleogels (AuG) using stearic acid as a gelator. A series of AuG was formulated by incorporating different proportions of AuNPs and a fixed amount of ciprofloxacin hydrochloride (drug) to establish that the composition with the highest concentration of AuNP (d-AuG4) was associated with the best iontophoretic response, validated via the corresponding in vitro drug release under AC field-induced iontophoresis. The sample d-AuG4 exhibited both drug and AuNP permeation across the whole pig ear skin thickness within as early as 1 h under the iontophoresis condition. With relevant control experiments, it was shown that the transport of AuNPs through the stratum corneum tissue and across the whole skin was possible upon the simultaneous fulfillment of two conditions: the presence of a skin permeation enhancer (stearic acid) within the oleogel and iontophoresis. While the literature reported that the permeation time for any free inorganic nanoparticle through the full-skin thickness varied within a few days, the permeation enhancement technique developed here reduced the corresponding delivery time for the AuNPs to a few hours. The extent of AuNP permeation that occurred in the microgram (per cm^-2) scale was found to be affected by the duration of iontophoresis, suggesting that AuNPs' rapid transdermal entry can be simultaneously triggered and modulated by iontophoretic conditions.

Synthesis and characterization of nanostructured lipid-poloxamer organogels for enhanced skin local anesthesia

The aim of this study was to synthesize a novel drug delivery system using organogels (ORGs) and characterize its physicochemical properties, in vitro and ex vivo permeation abilities, cytotoxicity and in vivo local anesthetic effects. The ORG formulations contained a mixture of oleic acid-lanolin (OA-LAN), poloxamer (PL407), and the commonly used local anesthetic lidocaine (LDC). The main focus was to evaluate the impact of LAN and PL407 concentrations on the ORG structural features and their biopharmaceutical performance. Results revealed that LDC, OA, and LAN incorporation separately shifted the systems transitions phase temperatures and modified the elastic/viscous moduli relationships (G'/G″ = ~15×). Additionally, the formulation with the highest concentrations of LAN and PL407 reduced the LDC flux from ~17 to 12 μg·cm^-2·h^-1 and the permeability coefficients from 1.2 to 0.62 cm·h^-1 through ex vivo skin. In vivo pharmacological evaluation showed that the ORG-based drug delivery system presented low cytotoxicity, increased and prolonged the local anesthetic effects compared to commercial alternatives. The data from this study indicate that ORG represent a promising new approach to effectively enhance the topical administration of local anesthetics.