Objective: The objective of the present investigation was to develop olive and soybean oil-based oleogels with Span 40 and/or Tween 80 (as gelator and/or surfactant) and determine the critical gelator concentration (CGC), characterise and compare the rheological, thermal properties and drug release profile of the gels formed for topical delivery. Methods: Olive and soybean oil-based Span 40 and Span 40/Tween 80 oleogel formulations were prepared by solid fiber mechanism and subjected to organoleptic evaluation, FT-IR spectroscopy, thermal analysis, rheological study, kinetic modeling of gelation and drug release. Results: The critical gelator (Span 40) concentration was found to be lower for olive oil (12% w/v) and depend on the type of oil. Tween 80 reduced CGC of soybean oleogels only. Soybean oil-based oleogel containing 18% w/v Span 40 was found to form more flexible, less viscous and thermally less stable formulation with better release of paracetamol as evident from lower melt flow index, Tg value, lower β and higher α value compared to olive oil-based oleogel with 12% w/v Span 40 (CGC). Surfactant addition can be assumed to modify the microarchitecture of the oleogels to a great extent to produce more flexible and thermally stable gels with even better drug release profile. Span-Tween based soybean oleogel formed a gel-matrix whereas matrix in olive oil-based oleogels containing Span only became slightly flexible to release the drug in zero-order fashion on the addition of surfactant cogelator. Conclusion: Nature of oil exerts profound influence on the rheological, thermal and release profile of oleogels containing Span 40 as gelator and/or Tween 80 as surfactant cogelator.

In the 21st century, melanoma and non-melanoma skin cancers have become an epidemic outbreak worldwide. Therefore, the exploration of all potential preventative and therapeutic measures based on either physical or bio-chemical mechanisms is essential via understanding precise pathophysiological pathways (Mitogen-activated protein kinase, Phosphatidylinositol 3-kinase Pathway, and Notch signaling pathway) and other aspects of such skin malignancies. Nano-gel, a three-dimensional polymeric cross-linked porous hydrogel having a diameter of 20–200 nm, possesses dual properties of both hydrogel and nanoparticle. The capacity of high drug entrapment efficiency with greater thermodynamic stability, remarkable solubilization potential, and swelling behavior of nano-gel becomes a promising candidate as a targeted drug delivery system in the treatment of skin cancer. Nano-gel can be either synthetically or architectonically modified for responding to either internal or external stimuli, including radiation, ultrasound, enzyme, magnetic, pH, temperature, and oxidation-reduction to achieve controlled release of pharmaceuticals and several bio-active molecules such as proteins, peptides, genes via amplifying drug aggregation in the active targeted tissue and reducing adverse pharmacological effects. Several drugs, such as anti-neoplastic biomolecules having short biological half-lives and prompt enzyme degradability capacity, must be appropriate for administration employing either chemically bridged or physically constructed nano-gel frameworks. The comprehensive review summarizes the advancement in the preparation and characterization methods of targeted nano-gel with enhanced pharmacological potential and preserved intracellular safety limits for the mitigation of skin malignancies with a special emphasize on skin cancer inducing pathophysiological pathways and prospective research opportunities for skin malignancy targeted nano-gels.

Intranasal gel formulation with mucilage of natural origin has been potentially explored as an alternative dosage form of drug administration. The purpose of present investigation was to develop paracetamol loaded nasal gel with sweet basil seed mucilage (BSM) as a gelling agent obtained by thermal-hydration process and to characterise both mucilage as well as the gel formulations. Phytochemical screening of BSM reveals it to be rich in carbohydrates. The FT-IR spectrum of the mucilage exhibits the presence of O-H, C-H, and-COO −. The mucilage showed high swelling index of 462% and relative viscosity of BSM dispersion (0.25% w/v) in nasal medium was found to be 2.94 at 25⁰ C. Nasal gel formulations demonstrated satisfactory pH, spreadability, extrudibility and drug content. The in vitro release profile of G1 (6%w/w BSM) demonstrated almost 95% release with Korsmeyer-Peppas kinetics with highest values of permeability coefficient and steady-state flux. Other formulations with 8-10%w/w BSM exhibited 70-80% release within 2.5 hours. G2 and G3 followed zero order kinetics with quasi-Fickian diffusion. The study indicates that G1 (6 %w/w BSM) can be selected for nasal gel formulation which may be used for in vivo studies in future.

Objective: Hydrogels or emulgels are recommended for topical application to elicit a local effect. However, they suffer from stability problems. The present study deals with the formulation and comparison of thermally stable soybean oil-based novel topical organogels (soy-gels) using two different gelators (Span 40 and Span 60) for controlled drug delivery. Methods: Soy-gels (8 batches) were developed with Span 40 and Span 60 by solid fiber mechanism and characterized for viscosity, gelation kinetics behavior, gel-sol transition parameters, drug content, in vitro drug release pattern, and changes occurring during accelerated thermal stability studies. Results: Fourier transformed infrared spectroscopic confirmed the compatibility among the organogel components and paracetamol. The formulations exhibited skin and hemocompatibility. The viscosity of Span 60 based soy-gels was found to be approximately 10 times higher than those of Span 40 based formulations. In comparison to Span 40, Span 60 induced faster gelation (3–6 min) of soybean oil at lower concentration (16% w/v) forming less flexible but thermally more stable soy-gels demonstrating higher Tg values. Higher flexibility and lower viscosity accounted for improved drug diffusion (both Fickian and non-Fickian) from Span 40 gels of varying concentrations in pH 5.8. However, zero-order drug release was observed in organogel with 18% w/v Span 40 only and all Span 60-based formulations except the one with 22% w/v Span 60. Non-Fickian drug diffusion occurred from Span 60 based soy-gels. A gradual increase in gelation time was observed until five cycles of freeze-thaw. Conclusion: Therefore, the choice of organogelator governs the rheological, thermal, and drug diffusion properties of soy-gels intended for topical application.

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