Jéssica Bassi da Silva

Photodynamic therapy (PDT) is a non-invasive treatment involving a photosensitizer (PS), light source, and tissue oxygen. Protoporphyrin IX (PpIX) is commonly used as a PS due to its tumor-targeting properties and phototoxicity. However, the physicochemical properties of PpIX foster self-aggregation, which is a challenge for its incorporation into pharmaceutical formulations. This study aimed to evaluate the solubility of PpIX in distinct solvent systems to support the development of novel pharmaceutical formulations. The shake-flask method was employed, using purified water, 50% ethanol (EtOH50), 77% ethanol (EtOH77), absolute ethanol (EtOHabs), and polymeric systems containing 10% (w/w) poloxamer 407 (P407) in water, in EtOH50 or in EtOH77. Approximately 10 to 25 mg of PpIX was added to 25 mL of the solvent, and the solutions were stirred at 100 rpm, at 37 °C, for up to 96 h. The PpIX concentration was measured by using a validated method (R = 0.9973), with equilibrium reached within 30 min. The dissolution profiles of the micellar systems were also evaluated using the Korsmeyer–Peppas model with lag time (t_lag), which indicated a Fickian diffusion mechanism, preceded by a thermodynamically driven accommodation stage of PpIX into the micelles. The solubility of PpIX ranged from 0.138 mg/mL in water to 0.593 mg/mL in water containing 10% (w/w) P407. The solubility of PpIX in EtOH50 and EtOH77 with 10% (w/w) P407 was 0.503 and 0.507 mg/mL, respectively, while EtOHabs yielded the lowest solubility among ethanolic solvents (0.179 mg/mL). These results indicate that water and EtOHabs are unsuitable solvents for PpIX, whereas the nanostructured systems containing P407 showed the greatest potential for future pharmaceutical applications, mainly the aqueous one because of its low toxicity considering topical preparations.

The use of foods to color other foods (coloring food) should be considered in food production. In this study, freeze-dried canistel (Pouteria campechiana (Kunth) Baehni) pulp underwent a photostability test. A blue LED light with a maximum intensity of 420 nm was utilized to induce photodegradation of the pulp. After irradiation, the samples were analyzed using photoacoustic spectroscopy. Different concentrations (2%, 4%, and 6%) of the pulp were employed as coloring food in ice cream, and the ice cream was thoroughly characterized. Photoacoustic spectroscopy provided valuable insights into dehydrated canistel pulp, revealing two stages of photoreaction involving carotenoids (violaxanthin and ξ-carotene) and demonstrating photostability under visible LED irradiation. The ice cream made with natural food dye produce elevated levels of bioactive compounds and retained a stable color throughout storage. All ice creams exhibited thixotropy. Ice creams with higher pulp concentrations displayed greater resistance to shear stress and, in sensory tests, received the highest scores, attributed to their intense yellow color. Dehydrated canistel pulp holds significant potential for use as food coloring in the industry due to its photostability.

Summary: Aqueous extract rich in phenolic compounds and carbohydrates obtained as a co‐product during the trub‐debittering process can be used as a new sustainable ingredient to improve food quality properties. This water‐soluble extract (WE) was used for evaluating its own antioxidant capacity when added to processed cheese at up to 1.00% (w/w); and were also evaluated for total phenolic compounds, antioxidant activity, FTIR spectroscopy, lipid oxidation, oxidative stability, texture and rheological properties. WE addition increased the antioxidant activity of processed cheese by up to 88.40% and 81.90% for DPPH and ABTS, reduced the product lipid oxidation by up to 54.31% and showed greater oxidative stability (Rancimat) compared to the Control. Samples melting property was not changed, and samples with WE showed a more stable structure after melting. Use of WE showed that it can be used as natural antioxidant in processed cheese, improving its quality and texture properties.

Recently, the number of new cases of cutaneous leishmaniasis has been of concern among health agencies. Research that offers new therapeutic alternatives is advantageous, especially those that develop innovative drugs. Therefore, this paper presents the incorporation of Copaifera reticulata Ducke and chlorophyll extract into Pluronic^®® F127 and Carbopol gels, under optimized polymer quantities. The chlorophyll extract (rich in photosensitizing compounds) was obtained by continuous-flow pressurized liquid extraction (PLE), a clean, environmentally friendly method. The system aims to act as as a leishmanicidal, cicatrizant, and antibiotic agent, with reinforcement of the photodynamic therapy (PDT) action. Rheological and mechanical analyses, permeation studies and bioadhesiveness analyses on human skin, and PDT-mediated activation of Staphylococcus aureus were performed. The emulgels showed gelation between 13° and 15 °C, besides pseudoplastic and viscoelastic properties. Furthermore, the systems showed transdermal potential, by releasing chlorophylls and C. reticulata Ducke into the deep layers of human skin, with good bioadhesive performance. The application of PDT reduced three logarithmic colony-forming units of S. aureus bacteria. The results support the potential of the natural drug for future clinical trials in treating wounds and cutaneous leishmania.

The use of products containing natural and sustainable substances has shown a remarkable growth in the pharmaceutical and cosmetic market, such as in the compounding pharmacy. This research aimed to develop, characterize, and evaluate the cutaneous bioengineering of natural and sustainable emulsions, providing a vehicle base for topical preparations. Nine O/W emulsions were developed changing the nonionic self-emulsifying wax (Cetearyl Olivate (and) Sorbitan Olivate, Cetearyl Glucoside (and) Cetearyl Alcohol, Candelilla/Jojoba/Rice Bran Polyglyceryl-3 Esters (and) Glyceryl Stearate (and) Cetearyl Alcohol (and) Sodium Stearoyl Lactylate), with or without the anionic co-emulsifier (Sodium Stearoyl Glutamate). They were characterized through preliminary stability tests, rheology and accelerated physicochemical stability study. Four formulations were approved (FB1, FB2, FB3 and FB5), but only FB1 (Cetearyl Olivate (and) Sorbitan Olivate with Sodium Stearoyl Glutamate) was considered stable, being selected for preservative efficacy evaluation and the cutaneous bioengineering. The hydration and transepidermal water loss (TEWL) of stratum corneum were analyzed comparing with a conventional topical vehicle (Emulsifying Wax NF). The clinical study showed that FB1 improved the skin hydration with no significant changes for TEWL, but demonstrated considered values. The FB1 could be classified as “skin friendly” and represents a promising natural and sustainable vehicle in compounded pharmacy preparations.

In this study, we developed a bioadhesive emulsion-filled gel containing a high amount of Copaifera reticulata Ducke oil-resin as a veterinary or human clinical proposal. The phytotherapeutic system had easy preparation, low cost, satisfactory healing ability, and fly repellency, making it a cost-effective clinical strategy for wound care and myiasis prevention. Mechanical, rheological, morphological, and physical stability assessments were performed. The results highlight the crosslinked nature of the gelling agent, with three-dimensional channel networks stabilizing the Copaifera reticulata Ducke oil-resin (CrD-Ore). The emulgel presented antimicrobial activity, satisfactory adhesion, hardness, cohesiveness, and viscosity profiles, ensuring the easy spreading of the formulation. Considering dermatological application, the oscillatory responses showed a viscoelastic performance that ensures emulgel retention at the action site, reducing the dosage frequencies. In Vivo evaluations were performed using a case report to treat ulcerative skin wounds aggravated by myiasis in calves and heifers, which demonstrated healing, anti-inflammatory, and repellent performance for the emulsion-filled gel. The emulgel preparation, which is low in cost, shows promise as a drug for wound therapy.

Microneedles (MNs) are a means to break the protective skin barrier in a minimally invasive way. By creating temporary micropores, they make biologically active agents available in the skin layers. Propolis (PRP) is a gum resin with a complex chemical composition, produced by bees Apis mellifera L. and showing several therapeutic properties (i.e., antibacterial, antiviral, antifungal, anti-inflammatory, healing, and immunomodulatory properties). The administration of PRP extracts by conventional routes has some disadvantages, such as running off over the skin in liquid or emulsion form. When taken orally, the extracts have a strong and unpleasant taste. The aim of this work was to fabricate and characterize microneedles containing polyvinyl alcohol, polyvinylpyrrolidone, poloxamer P407, and an ethanolic or glycolic extract of PRP. Also, the obtained structures were microscopically and mechanically characterized. The results of the mechanical analysis showed that formulations containing 3% of P407 presented the highest compression values in a hard surface, which was also confirmed by the height and base values of the morphological analysis and by the microscopy images. It was possible to design MNs and select the best formulations for future tests. MNs containing an ethanolic extract of PRP showed to be better structured than MNs containing a glycolic extract of PRP. The MNs obtained in these studies proved to be a promising platform for the topical application of PRP.

Emulgels are obtained by the entrapment of an organic phase within a three-dimensional network built by hydrophilic molecules. Polymers based on cross-linked poly(acrylic acid) have been utilized as gel matrices, improving adhesiveness, rheological and mechanical performance. Propolis (PRP) produced by Apis mellifera L. bees displays a wide range of biological activities. Together with curcumin (CUR), they may show synergic anti-inflammatory, antioxidant and antimicrobial action on skin disorders. This work investigated the effect of vegetable oils (sweet almond, andiroba, and passion fruit) with regard to the physicochemical properties of emulgels composed of Carbopol 934P^®, Carbopol 974P^®, or polycarbophil aiming the CUR and PRP delivery. Physicochemical stability enabled the selection of systems containing passion fruit or andiroba oil. Mechanical and rheological characteristics provided rational comprehension of how vegetable oils and bioactive agents affect the structure of emulsion gels. All formulations exhibited high physiochemical stability and properties dependent on the polymer type, oil, and bioactive agent. Formulations displayed pseudoplastic, thixotropic and viscoelastic properties. Emulgels containing andiroba oil were the most stable systems. Carbopol 934P^® or polycarbophil presence resulted in formulations with improved smoothness and mechanical properties. Systems containing andiroba oil and one of these two polymers are promising for further investigations as topical delivery systems of CUR and/or PRP on the skin and mucous membranes.