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Camila O Cardoso,1 Seila Tolentino,1 Tais Gratieri,1 Marcilio Cunha-Filho,1 Renata FV Lopez,2 Guilherme M Gelfuso1 1Laboratory of Food, Drugs, and Cosmetics (LTMAC), University of Brasilia, Brasília, 70910-900, DF, Brazil; 2School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14040-903, SP, BrazilCorrespondence: Guilherme M GelfusoUniversity of Brasília, Department of Pharmacy, Campus Universitário Darcy Ribeiro, Brasília, 70910-900, DF, BrazilTel +55 61 3107-1990Email gmgelfuso@unb.brAbstract: Alopecia is a clinical condition related to hair loss that can significantly affect both male and female adults’ quality of life. Despite the high market demand, only few drugs are currently approved for alopecia treatment. Topical formulations still bring drawbacks, such as scalp irritation with frequent use, and low drug absorption to the site of action, which limits the efficacy. The most recent research points out that different formulation technology could circumvent the aforementioned flaws. Such technology includes incorporation of drugs in rigid or deformable nanoparticles, strategies involving physical, energetical and mechanical techniques, such as iontophoresis, sonophoresis, microneedling, and the use of solid effervescent granules to be hydrated at the moment of application in the scalp. In this paper, the progress of current research on topical formulations dedicated to the treatment of alopecia is reviewed and discussed.Keywords: alopecia, drug delivery, hair follicle, iontophoresis, nanoparticles, topical treatment

Dacarbazine (DTIC) is the drug of choice for melanoma treatment, but its systemic administration is related to several adverse effects. Here, DTIC topical delivery stimulated by iontophoresis is proposed to overcome such drawbacks. Hence, this work analyzed the impact of anodal iontophoresis on DTIC cutaneous delivery to provide an innovative topical alternative for melanoma treatment. The electrical stability of the drug was evaluated prior to the iontophoretic experiments, which demonstrated the need to add an antioxidant to the drug formulation. DTIC cutaneous permeation was evaluated in vitro for 6 h using three current densities (0.10, 0.25, and 0.50 mA/cm 2 ). In addition, the effect of DTIC against skin cancer cells (MeWo and WM164) was investigated for 72 h of exposure to the drug. Iontophoresis stimulated skin drug permeation compared to the passive control. However, the antioxidant presence reduced DTIC permeation under the lower currents of 0.10 and 0.25 mA/cm 2 , which was compensated by increasing the current density to 0.50 mA/cm 2 . At 0.50 mA/cm 2 , iontophoresis enhanced topical cutaneous drug permeation 7-fold (p < 0.05) compared to the passive control. DTIC showed a concentration-dependent antiproliferative effect on melanoma cell lines. Thus, iontophoresis intensifies DTIC skin penetration in concentrations that can reduce cell viability and induce cell death. In conclusion, DTIC cutaneous delivery mediated by iontophoresis is a promising approach for treating melanomas and other skin tumors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A novel sanitizer tablet containing clove essential oil (CO) microemulsion was developed. A preformulation study using nuclear magnetic resonance and thermal analyses showed component compatibility. The main components of the samples remained intact despite a color change, probably due to a strong acid-base interaction between eugenol and diethanolamine. The CO microemulsion showed acaricidal and larvicidal activities superior to the commercial product, with product efficacy of 99.9% and larvae mortality of 94%. Optimal spray-drying conditions were achieved with inlet and outlet temperatures of 50°C and 40°C, respectively, an aspiration rate of 1 m3 min⁻1, and a 0.25 L h⁻1 injection flow. The feed suspension comprised 50% (v/v) liquid soap, 37.5% (v/v) water, 12.5% (v/v) ethanol, and 5.0% (w/v) silica. This formulation and processing parameters allowed for successful free-flow powder formation, providing a suitable matrix for incorporating the CO microemulsion via wet granulation without heating. Finally, sanitizer tablets produced from such granules resulted in a uniform product with low weight variation (coefficient of variation of 0.15%), eugenol content of 95.5% ± 3.3, and friability of 0.58%. Furthermore, the tablets showed rapid aqueous dispersion, forming a colloidal system with particle sizes of 221 nm and a zeta potential of -17.2 mV. Antimicrobial activity tests demonstrated the effectiveness of the sanitizer tablet against bacteria and fungi, exhibiting comparable antimicrobial potency to isolated CO. Hence, the sanitizer tablet developed represents a promising candidate as a practical and efficient solution for pest control, offering strong antimicrobial and acaricidal activity., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Gross et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Hair follicles (HFs) represent a route of interest to drug delivery for treating several skin conditions. Iontophoresis, on the other hand, is a physical method to enhance drug permeation by applying a low electrical current to the formulation. HFs can be targeted following topical iontophoretic application, as they represent a pathway of lower electrical resistance, as well as a drug reservoir, in particular useful for nanoparticles (NPs), which can preferably accumulate in these structures. Combining both strategies may provide optimal results, but the literature still lacks evidence of the ideal NP characteristics for the iontophoretic drug delivery targeting the HFs. Here, we aimed to evaluate the effect of gelatin NPs' size and charge under iontophoresis application on NPs' deposition into the HFs. Four gelatin NP formulations were produced with varying gelatin concentrations and gelatin types (positively charged type A and negatively charged type B), with sizes ranging from 220 to 770 nm. A fluorescent dye, TRITC-dextran 150 kDa, was encapsulated for monitoring NPs deposition. Cutaneous penetration experiments were performed in vitro with and without iontophoresis for 6 h with pig ear skin. The deposition profile was assessed by confocal laser scanning microscopy. Photomicrographs showed a higher accumulation of the larger positively charged NPs (AL), reaching deeper portions of HFs, and showed iontophoresis further increased their deposition, resulting in the highest signal. In conclusion, these findings shed light on the applications of NPs and bring novel treatment opportunities for several diseases compromising the hair follicles., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This study aimed to develop mucoadhesive chitosan-based films capable of enhancing the curcumin penetration into the oral mucosa to treat oral cancers. We developed three films containing medium molecular weight chitosan (190-310 KDa) and other excipients (polyvinyl alcohol, Poloxamer®407, and propylene glycol) that have proven to be compatible with each other and with curcumin in thermal analyses. The films were smooth, flexible, and precipitates free, with uniform weight and thickness, pH compatible with the oral mucosa, resistance to traction, and entrapped curcumin in a high proportion. They also exhibited necessary swelling and mucoadhesion for tissue adherence. Ex vivo penetration studies proved that the films significantly increased the penetration of curcumin into the oral mucosa compared to control, even when the mucosa was subjected to a condition of simulated salivation. Curcumin exhibited cytotoxic activity in vitro in the two head and neck cancer cell lines (FaDu, SCC-9) at doses close to those found in penetration studies with the films. When combined with radiotherapy, curcumin demonstrated superiority over single doses of radiotherapy at 4, 8, and 12 Gy. Therefore, the developed films may represent a promising alternative for the topical treatment of oral tumors., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Envisaging to improve the evaluation of ophthalmic drug products while minimizing the need for animal testing, our group developed the OphthalMimic device, a 3D-printed device that incorporates an artificial lacrimal flow, a cul-de-sac area, a moving eyelid, and a surface that interacts effectively with ophthalmic formulations, thereby providing a close representation of human ocular conditions. An important application of such a device would be its use as a platform for dissolution/release tests that closely mimic in vivo conditions. However, the surface that artificially simulates the cornea should have a higher resistance (10 min) than the previously described polymeric films (5 min). For this key assay upgrade, we describe the process of obtaining and thoroughly characterizing a hydrogel-based hybrid membrane to be used as a platform base to simulate the cornea artificially. Also, the OphthalMimic device suffered design improvements to fit the new membrane and incorporate the moving eyelid. The results confirmed the successful synthesis of the hydrogel components. The membrane's water content (86.25 ± 0.35 %) closely mirrored the human cornea (72 to 85 %). Furthermore, morphological analysis supported the membrane's comparability to the natural cornea. Finally, the performance of different formulations was analysed, demonstrating that the device could differentiate their drainage profile through the viscosity of PLX 14 (79 ± 5 %), PLX 16 (72 ± 4 %), and PLX 20 (57 ± 14 %), and mucoadhesion of PLXCS0.5 (69 ± 1 %), PLX16CS1.0 (65 ± 3 %), PLX16CS1.25 (67 ± 3 %), and the solution (97 ± 8 %). In conclusion, using the hydrogel-based hybrid membrane in the OphthalMimic device represents a significant advancement in the field of ophthalmic drug evaluation, providing a valuable platform for dissolution/release tests. Such a platform aligns with the ethical mandate to reduce animal testing and promises to accelerate the development of safer and more effective ophthalmic drugs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The OphthalMimic is a 3D-printed device that simulates human ocular conditions with artificial lacrimal flow, cul-de-sac area, moving eyelid, and a surface to interact with ophthalmic formulations. All tests with such a device have used a continuous artificial tear flow rate of 1 mL/min for 5 min. Here, we implemented protocol variations regarding the application time and simulated tear flow to increase the test's discrimination and achieve reliable performance results. The new protocols incorporated the previously evaluated 0.2% fluconazole formulations containing or not chitosan as a mucoadhesive component (PLX16CS10 and PLX16, respectively) and novel moxifloxacin 5% formulations, either in a conventional formulation and a microemulsion (CONTROL and NEMOX, respectively). The flow rate was reduced by 50%, and a pre-flow application period was also included to allow formulation interaction with the membrane. The OphthalMimic model was used with both polymeric and hydrogel-based hybrid membranes, including a simulated eyelid. Lowering the flow made it feasible to prolong the testing duration, enhancing device discrimination potential. The hydrogel membrane was adequate for testing nanostructure formulations. The OphthalMimic device demonstrated once again to be a versatile method for evaluating the performance of ophthalmic drug formulations with the potential of reducing the use of animals for experimentation.

Considering the health relevance of Chagas' disease, recent research efforts have focused on developing more efficient drug delivery systems containing nifurtimox (NFX). This paper comprehensively investigates NFX through conformational analysis and spectroscopic characterization. Using a conformer-rotamer ensemble sampling tool (CREST-xtb), five distinct conformers of NFX were sampled within a 3.0 kcal mol -1 relative energy window. Subsequently, such structures were used as inputs for geometry optimization by density functional theory (DFT) at B3LYP-def2-TZVP level of theory. Notably, harmonic vibrational frequencies were calculated to establish an in-depth comparison with experimental results and existing literature for the NFX or similar molecules and functional groups, thereby achieving a widely reasoned assignment of the mid-infrared band absorptions for the first time. Moreover, UV-VIS spectra of NFX were obtained in several solvents, enabling the determination of the molar absorptivity coefficient for the two electronic transitions observed for NFX. Among the aprotic solvents, a bathochromic effect was observed in the function of the dielectric constants. Furthermore, a hypochromic effect was observed when the drug was dissolved in protic solvents. These findings offer crucial support for new drug delivery systems containing NFX while demonstrating the potential of spectrophotometric studies in establishing quality control assays for NFX drug products., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The necessity of animal-free performance tests for novel ophthalmic formulation screening is challenging. For this, we developed and validated a new device to simulate the dynamics and physical-chemical barriers of the eye for in vitro performance tests of topic ophthalmic formulations. The OphthalMimic is a 3D-printed device with an artificial lacrimal flow, a cul-de-sac area, a support base, and a simulated cornea comprised of a polymeric membrane containing poly-vinyl alcohol 10 % (w/v), gelatin 2.5 % (w/v), and different proportions of mucin and poloxamer, i.e., 1:1 (M1), 1:2 (M2), and 2:1 (M3) w/v, respectively. The support base is designed to move between 0° and 50° to replicate the movement of an eyelid. We challenged the model by testing the residence performance of poloxamer®407 16 % and poloxamer®407 16 % + chitosan 1 % (PLX16CS10) gels containing fluconazole. The test was conducted with a simulated tear flow of 1.0 mL.min -1 for 5 min. The OphthalMimic successfully distinguished PLX16 and PLX16C10 formulations based on their fluconazole drainage (M1: 65 ± 14 % and 27 ± 10 %; M2: 58 ± 6 % and 38 ± 9 %; M3: 56 ± 5 % and 38 ± 18 %). In conclusion, the OphthalMimic is a promising tool for comparing the animal-free performance of ophthalmic formulations., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Melanoma is responsible for more than 80% of deaths related to skin diseases. Ibrutinib (IBR), a Bruton's tyrosine kinase inhibitor, has been proposed to treat this type of tumor. However, its low solubility, extensive first-pass effect, and severe adverse reactions with systemic administration affect therapeutic success. This study proposes developing and comparing the performance of two compositions of nanostructured lipid carriers (NLCs) to load IBR for the topical management of melanomas in their early stages. Initially, the effectiveness of IBR on melanoma proliferation was evaluated in vitro, and the results confirmed that the drug reduces the viability of human melanoma cells by inducing apoptosis at a dose that does not compromise dermal cells. Preformulation tests were then conducted to characterize the physical compatibility between the drug and the selected components used in NLCs preparation. Sequentially, two lipid compositions were used to develop the NLCs. Formulations were then characterized and subjected to in vitro release and permeation tests on porcine skin. The NLCs containing oleic acid effectively controlled IBR release over 24 h compared to the NLCs composed of pomegranate seed oil. Furthermore, the nanoparticles acted as permeation enhancers, increasing the fluidity of the lipids in the stratum corneum, as determined by EPR spectroscopy, which stimulated the IBR penetration more profoundly into the skin. However, the NLCs composition also influenced the permeation promotion factor. Thus, these findings emphasize the importance of the composition of NLCs in controlling and increasing the skin penetration of IBR and pave the way for future advances in melanoma therapy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Despite nifurtimox (NFX) being a traditional drug for treating Chagas disease, some of its physicochemical properties are still unknown, especially its thermal behavior, which brings important outcomes regarding stability and compatibility. In this work, a comprehensive study of NFX's thermal properties was conducted to assist incremental innovations that can improve the efficacy of this drug in novel pharmaceutical products. For this purpose, thermal analyses associated with spectroscopy and spectrometry techniques were used. DSC analyses revealed that the melt crystallization of the NFX led to its amorphous form with the possible formation of a minor fraction of a different crystalline phase. Coats-Redfern method using TGA results indicated the activation energy of NFX non-isothermal degradation as 348.8 ± 8.2 kJ mol -1 , which coincides with the C-NO 2 bond dissociation energy of the 2-nitrofuran. Investigation of the isothermal degradation kinetics using FTIR 2D COS showed the possible detachment of radical NO 2 and ethylene from the NFX structure, which could affect its mechanism of action. A preliminary mechanism for the thermal degradation of this drug was also proposed. The results enhanced the understanding of NFX's thermal properties, providing valuable insights, especially for developing NFX-based pharmaceutical products that involve thermal processing., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Introduction: The success of endodontic treatment depends on the significant disinfection of the root canal system, its irregularities, and dentinal tubules. However, achieving complete disinfection remains challenging, with frequent failures and occurrence of secondary infections. Here, we propose using iontophoresis to increase the penetration and distribution of disinfecting agents into root canals, using methylene blue for proof-of-concept., Methods: The marker was applied in bovine root canals, and the radial distribution of the dye in the dentinal tubules was evaluated by optical microscopy. Iontophoresis was applied at 0.5 and 1.5 mA for 5 and 15 min., Results: A significant statistical difference (p < 0.05) was observed in the marker penetration between passive and iontophoretic applications. Both current density and application time had an important effect on methylene blue distribution, with a greater efficacy delivery to the apical region achieved after 1.5 mA for 5 min or 0.5 mA for 15 min, showing longer application time can compensate for lower application current., Conclusion: Iontophoresis increases the penetration and distribution of methylene blue into bovine root canals and dentinal tubules, including its innermost portions., Clinical Significance: Iontophoresis has shown to be a promising technique for root canal and dentinal tubule disinfection., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

This work aimed to develop a three-dimensional (3D) wearable drug-loaded earring tap to treat affections caused by aesthetic perforations. The initial phase involved a combination of polymers to prepare filaments for fused deposition modeling (FDM) 3D printing using a centroid mixture design. Optimized filament compositions were used in the second phase to produce 3D printed earring taps containing the anti-inflammatory naringenin. Next, samples were assessed via physicochemical assays followed by in vitro skin permeation studies with porcine ear skin. Two filament compositions were selected for the study's second phase: one to accelerate drug release and another with slow drug dissolution. Both filaments demonstrated chemical compatibility and amorphous behavior. The use of the polymer blend to enhance printability has been confirmed by rheological analysis. The 3D devices facilitated naringenin skin penetration, improving drug recovery from the skin's most superficial layer (3D device A) or inner layers (3D device B). Furthermore, the devices significantly decreased transdermal drug delivery compared to the control containing the free drug. Thus, the resulting systems are promising for producing 3D printed earring taps with topical drug delivery and reinforcing the feasibility of patient-centered drug administration through wearable devices.

This study aims to investigate the effect of the preparation of solid dispersions using supercritical CO 2 (scCO 2 ) on the physicochemical properties and the performance of supramolecular gels based on polymer-cyclodextrin (CD) interactions (named poly(pseudo)rotaxanes, PPR) envisaging a transdermal administration. Solid dispersions containing Soluplus ® , the antihypertensive drug carvedilol (CAR), and CD (αCD or HPβCD) were prepared and characterized by HPLC, XRPD, FTIR, and DSC. PPRs prepared from solid dispersions (SCF gels) and the corresponding physical mixtures (PM gels) were analyzed regarding rheology, morphology, in vitro drug diffusion, and ex vivo drug skin permeation. The application of scCO 2 led to the loss of the crystalline lattice of CAR while preserving its chemical identity. On the contrary, αCD crystals were still present in the SCF solid dispersions. SCF gels were more uniform than their corresponding PM, and the supercritical treatment resulted in changes in the rheological behavior, reducing the viscosity. CAR in vitro diffusion was significantly higher (p < 0.05) for the αCD-based SCF gel than its corresponding PM gel. Drug skin permeation showed a significant increase in drug flux from CD-based SCF gels (containing αCD or HPβCD) compared to corresponding PM gels. Additionally, the pretreatment of the skin with αCD exhibited increased CAR permeation, suggesting an interaction between αCD and the skin membrane. Results evidenced that SCF processing decisively modified the properties of the supramolecular gels, particularly those prepared with αCD., (© 2023. The Author(s).)

Artificial intelligence has revolutionized many sectors with unparalleled predictive capabilities supported by machine learning (ML). So far, this tool has not been able to provide the same level of development in pharmaceutical nanotechnology. This review discusses the current data science methodologies related to polymeric drug-loaded nanoparticle production from an innovative multidisciplinary perspective while considering the strictest data science practices. Several methodological and data interpretation flaws were identified by analyzing the few qualified ML studies. Most issues lie in following appropriate analysis steps, such as cross-validation, balancing data, or testing alternative models. Thus, better-planned studies following the recommended data science analysis steps along with adequate numbers of experiments would change the current landscape, allowing the exploration of the full potential of ML.

Conventional treatments for cutaneous leishmaniasis, a neglected vector-borne infectious disease, can frequently lead to serious adverse effects. Paromomycin (PAR), an aminoglycoside antibiotic, has been suggested for the topical treatment of disease-related lesions, but even when formulated in high drug-loading dosage forms, presents controversial efficacy. The presence of five ionizable amino groups hinder its passive cutaneous penetration but make PAR an excellent candidate for iontophoretic delivery. The objective of this study was to verify the feasibility of using iontophoresis for cutaneous PAR delivery and to propose a topical passive drug delivery system that could be applied between iontophoretic treatments. For this, in vitro iontophoretic experiments evaluated different application durations (10, 30, and 360 min), current densities (0.1, 0.25, and 0.5 mA/cm 2 ), PAR concentrations (0.5 and 1.0 %), and skin models (intact and impaired porcine skin). In addition, 1 % PAR hydrogel had its penetration profile compared to 15 % PAR ointment in passive transport. Results showed iontophoresis could deliver suitable PAR amounts to dermal layers, even in short times and with impaired skin. Biodistribution assays showed both iontophoretic transport and the proposed hydrogel delivered higher PAR amounts to deeper skin layers than conventional ointment, even though applying 15 times less drug. To our knowledge, this is the first report of PAR drug delivery enhancement by iontophoresis. In summary, the association of iontophoresis with a topical application of PAR gel seems appropriate for improving cutaneous leishmaniasis treatment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The steady-state is a situation of little variability of species dominance and total biomass over time. Maintenance of cyanobacteria are often observed in tropical and eutrophic ecosystems and can cause imbalances in aquatic ecosystem. Bayeasian networks allow the construction of simpls models that summarizes a large amount of variables and can predict the probability of occurrence of a given event. Studies considering Bayeasian networks built from environmental data to predict the occurrence of steady-state in aquatic ecosystems are scarce. This study aims to propose a Bayeasian network model to assess the occurrence, composition and duration of cyanobacteria steady-state in a tropical and eutrophic ecosystem. It was hypothesized long lasting steady-state events, composed by filamentous cyanobacteria species and directly influenced by eutrophication and drought. Our model showed steady-state lasting between 3 and 17 weeks with the monodominance or co-dominance of filamentous species, mainly Raphidiopsis raciborskii and Planktothrix agardhii. These evens occurred frequently under drought and high turbidity, however higher nutrients concentrations did not increase the probability steady-state occurrence or longer duration. The proposed model appears as a tool to assess the effects of future warming on steady-state occurrence and it can be a useful to more traditional process-based models for reservoirs.

Dacarbazine (DTIC) is a chemotherapeutic drug currently used for the systemic treatment of melanomas. Considering the easy access to these tumors, a topical route of drug administration could provide a more comfortable and less toxic treatment. However, DTIC quantification aiming at the design of topical formulations is challenging, pondering all the interferents present in the drug samples recovered from the skin. Hence, this work intended to validate a selective chromatographic method for DTIC determination in skin permeation studies. A reversed-phase C 18 column was used as a stationary phase, and gradient elution of a mobile phase consisting of methanol and pH 6.5 sodium phosphate monohydrate buffer (0.01 mol/L) at a flow rate of 1.0 mL/min was implemented. DTIC was detected at 364 nm. The method was selective against skin interferents, linear (r = 0.9995) in a concentration range of 1.0-15.0 μg/mL, precise with an overall variation coefficient lower than 3.8%, accurate achieving recovery from the skin layers within 91-112%, and sensitive for the proposed application (detection limit = 0.10 μg/ mL, quantification limit = 0.30 μg/mL). Furthermore, the analytical method was successfully tested in in vitro skin permeation studies. In conclusion, the developed method is appropriate for DTIC analysis from the skin sample matrix., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Camila O. Cardoso reports financial support was provided by Coordination of Higher Education Personnel Improvement. Guilherme M. Gelfuso reports financial support was provided by Foundation for Research Support of the Federal District. Guilherme M. Gelfuso reports financial support was provided by National Council for Scientific and Technological Development., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Alopecia areata is managed with oral corticosteroids, which has known side effects for patients. Given that a topical application of formulations containing a corticoid and a substance controlling hair loss progression could reduce or eliminate such adverse effects and increase the patient's adherence to the treatment, this study prepares polymeric and lipidic nanoparticles (PNPs and NLCs) to co-entrap minoxidil and betamethasone and compares the follicular drug delivery provided by topical application of these nanoparticles. The prepared PNPs loaded 99.1 ± 13.0% minoxidil and 70.2 ± 12.8% betamethasone, while the NLCs entrapped 99.4 ± 0.1 minoxidil and 80.7 ± 0.1% betamethasone. PNPs and NLCs presented diameters in the same range, varying from 414 ± 10 nm to 567 ± 30 nm. The thermal analysis revealed that the production conditions favor the solubilization of the drugs in the nanoparticles, preserving their stability. In in vitro permeation studies with porcine skin, PNPs provided a 2.6-fold increase in minoxidil penetration into the follicular casts compared to the control and no remarkable difference in terms of betamethasone; in contrast, NLCs provided a significant (specifically, a tenfold) increase in minoxidil penetration into the hair follicles compared to the control, and they delivered higher concentrations of betamethasone in hair follicles than both PNPs and the control. Neither PNPs nor NLCs promoted transdermal permeation of the drugs to the receptor solution, which should favor a topical therapy. Furthermore, both nanoparticles targeted approximately 50% of minoxidil delivery to the follicular casts and NLCs targeted 74% of betamethasone delivery to the hair follicles. In conclusion, PNPs and NLCs are promising drug delivery systems for enhancing follicular targeting of drugs, but NLCs showed superior performance for lipophilic drugs.

Animal models are still used in the research and development of ophthalmic drug products, mainly due to the difficulty in simulating natural physiological conditions with in vitro models, as there is a lack of dynamic protection mechanisms. Therefore, developing alternative ophthalmic models that evaluate drug penetration in the cornea while applying dynamic protection barriers is a contemporary challenge. This study aimed to develop a dynamic ex vivo model using porcine eyes with a simulated lacrimal flow to evaluate the performance of pharmaceutical drug products. A glass donor cell to support a simulated tear flow was designed, optimized, and custom-made. The system was challenged with different formulations (with fluconazole) including excipients with different viscosities (poloxamer 407) and mucoadhesive properties (chitosan). The results were compared to those obtained from a conventional excised cornea model mounted in Franz-type diffusion cells. The dynamic model could differentiate formulations, while the static model did not, overestimating ex vivo drug penetrated amounts. Hence, the dynamic model with simulated tear flow showed to be a simple and promising new alternative method for the drug penetration of ophthalmic formulations that ultimately can reduce the number of animals used in research.

The in-situ formation of nanoparticles from polymer-based solid medicines, although previously described, has been overlooked despite its potential to interfere with oral drug bioavailability. Such polymeric pharmaceuticals are becoming increasingly common on the market and can become even more popular due to the dizzying advance of 3D printing medicines. Hence, this work aimed to study this phenomenon during the dissolution of 3D printed tablets produced with three different polymers, hydroxypropylmethylcellulose acetate succinate (HPMCAS), polyvinyl alcohol (PVA), and Eudragit RL PO® (EUD RL) combined with plasticizers and the model drug naringenin (NAR). The components' interaction, dissolution behavior, and characteristics of the formed particles were investigated employing thermal, spectroscopic, mechanical, and chromatographic assays. All the systems generated stable spherical-shaped particles throughout 24 h, encapsulating over 25% of NAR. Results suggest encapsulation efficiencies variations may depend on interactions between polymer-drug, drug-plasticizer, and polymer-plasticizer, which formed stable nanoparticles even in the drug absence, as observed with the HPMCAS and EUD RL formulations. Additionally, components solubility in the medium and previous formulation treatments are also a decisive factor for nanoparticle formation. In particular, the treatment provided by hot-melt extrusion and FDM 3D printing affected the dissolution efficiency enhancing the interaction between the components, reverberating on particle size and particle formation kinetics mainly for HPMCAS and EUD RL. In conclusion, the 3D printing process influences the in-situ formation of nanoparticles, which can directly affect oral drug bioavailability and needs to be monitored., Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Nanotechnology has been investigated for treatments of hair follicle disorders mainly because of the natural accumulation of solid nanoparticles in the follicular openings following a topical application, which provides a drug "targeting effect". Despite the promising results regarding the therapeutic efficacy of topically applied nanoparticles, the literature has often presented controversial results regarding the targeting of hair follicle potential of nanoformulations. A closer look at the published works shows that study parameters such as the type of skin model, skin sections analyzed, employed controls, or even the extraction methodologies differ to a great extent among the studies, producing either unreliable results or precluding comparisons altogether. Hence, the present study proposes to review different skin models and methods for quantitative and qualitative analysis of follicular penetration of nano-entrapped drugs and their influence on the obtained results, as a way of providing more coherent study protocols for the intended application.

This study sought to develop polymer-lipid hybrid solid dispersions containing the poorly soluble drug lopinavir (LPV) by hot-melt extrusion (HME). Hence, the lipid and polymeric adjuvants were selected based on miscibility and compatibility studies. Film casting was used to assess the miscibility, whereas thermal, spectroscopic, and chromatographic analyses were employed to evaluate drug-excipient compatibility. Extrudates were obtained and characterized by physicochemical tests, including in vitro LPV dissolution. Preformulation studies led to select the most appropriate materials, i.e., the polymers PVPVA and Soluplus®, the plasticizers polyethylene glycol 400 and Kolliphor® HS15, phosphatidylcholine, and sodium taurodeoxycholate. HME processing did not result in LPV degradation and significantly increased entrapment efficiency (93.8% ± 2.8 for Soluplus® extrudate against 19.8% ± 0.5 of the respective physical mixture). LPV dissolution was also increased from the extrudates compared to the corresponding physical mixtures (p < 0.05). The dissolution improvement was considerably greater for the Soluplus®-based formulation (24.3 and 2.8-fold higher than pure LPV and PVPVA-based extrudate after 120 min, respectively), which can be attributed to the more pronounced effects of HME processing on the average size and LPV solid-state properties in the Soluplus® extrudates. Transmission electron microscopy and chemical microanalysis suggested that the polymer-lipid interactions in Soluplus®-based formulation depended on thermal processing., (© 2023. The Author(s), under exclusive licence to American Association of Pharmaceutical Scientists.)

Introduction: Although the administration of drugs on the skin is a safe and noninvasive therapeutic alternative, producing formulations capable of disrupting the cutaneous barriers is still a challenge. In this scenario, extrusion-based techniques have emerged as disruptive technologies to ensure unique drug-excipient interactions that facilitate drug skin diffusion for systemic or local effect and even mean the key to obtain viable industrial products., Areas Covered: This article presents a comprehensive overview of extrusion-based techniques in developing pharmaceutical dosage forms for topical or transdermal drug delivery. First, the theoretical basis of how extrusion-based techniques can optimize the permeation of drugs through the skin is examined. Then, the current state-of-the-art of drug products developed by extrusion-based techniques, specifically by hot-melt extrusion (HME) and fused deposition modeling (FDM) 3D printing, are discussed and contrasted with the current pharmaceutical processes., Expert Opinion: A wide variety of pharmaceutical products can be obtained using HME and FDM 3D printing, including new dosage forms designed for a perfect anatomical fit. Despite the limitations of pharmaceutical products produced with HME and FDM 3D printing regarding thermal stability and available excipients, the advantages in industrial adaptability and improved bioavailability allied with patient-match devices certainly deserve full attention and investment.

Introduction: The skin is an attractive route for drug delivery. However, the stratum corneum is a critical limiting barrier for drug permeation. Nanoentrapment is a way to enhance cutaneous drug delivery, by diverse mechanisms, with a notable trend of nanoparticles accumulating into the hair follicles when topically applied. Iontophoresis is yet another way of increasing drug transport by applying a mild electrical field that preferentially passes through the hair follicles, for being the pathway of lower resistance. So, iontophoresis application to nanocarriers could further increase actives accumulation into the hair follicles, impacting cutaneous drug delivery., Areas Covered: In this review, the authors aimed to discuss the main factors impacting iontophoretic skin transport when combining nanocarriers with iontophoresis. We further provide an overview of the conditions in which this combination has been studied, the characteristics of nanosystems employed, and hypothesize why the association has succeeded or failed to enhance drug permeation., Expert Opinion: Nanocarriers and iontophoresis association can be promising to enhance cutaneous drug delivery. For better results, the electroosmotic contribution to the iontophoretic transport, mainly of negatively charged nanocarriers, charge density, formulation pH, and skin models should be considered. Moreover, the transfollicular pathway should be considered, especially when designing the nanocarriers.

Iontophoresis has been vastly explored to improve drug permeation, mainly for transdermal delivery. Despite the skin's electrical resistance and barrier properties, it has a relatively high aqueous content and is permeable to many drugs. In contrast, nails and teeth are accessible structures for target drug delivery but possess low water content compared to the skin and impose significant barriers to drug permeation. Common diseases of these sites, such as nail onychomycosis and endodontic microbial infections that reach inaccessible regions for mechanical removal, often depend on time-consuming and ineffective treatments relying on drug's passive permeation. Iontophoresis application in nail and teeth structures may be a safe and effective way to improve drug transport across the nail and drug distribution through dental structures, making treatments more effective and comfortable for patients. Here, we provide an overview of iontophoresis applications in these "hard tissues," considering specificities such as their high electrical resistivity. Iontophoresis presents a promising option to enhance drug permeation through the nail and dental tissues, and further developments in these areas could lead to widespread clinical use., (© 2022. Controlled Release Society.)

Aim: The dose response in growth inhibition of Staphylococcus aureus treated with colloidal copper oxide nanoparticles (CuO-NP) was evaluated. Methods: An in vitro microbial viability assay was conducted with CuO-NP concentrations spreading over the 0.4-848.0 μg/ml range. The dose-response curve was modeled with a double Hill equation. UV-Visible absorption and photoluminescence spectroscopies allowed tracking concentration-dependent modifications in CuO-NP. Results: Two specific phases separated by the critical concentration of 26.5 μg/ml were observed in the dose-response curve, with each exhibiting proper IC 50 parameters, Hill coefficients and relative amplitudes. Spectroscopy techniques reveal the occurrence of a concentration-triggered aggregation of CuO-NP starting from this critical concentration. Conclusion: The findings demonstrate a dose-related change in S. aureus sensitivity to CuO-NP, which probably arises from the aggregation of this agent.

This study aimed to investigate whether hot-melt extrusion (HME) processing can promote molecular encapsulation of a multi-component natural product composed of volatile and pungent hydrophobic substances (ginger oleoresin (OR)) with cyclodextrins. 6-Gingerol and 6-shogaol, the biomarkers of ginger OR, were quantified by HPLC. Phase-solubility studies were performed using β-cyclodextrin (βCD) and hydroxypropyl-β-cyclodextrin (HPβCD) for ginger OR complexation. Solid complexes were then prepared by thermal (HME)- and solvent (slurry (SL))-based methods. Morphology, thermal behavior, solubility, in vitro dissolution, and in vivo anti-inflammatory activity were evaluated. HPβCD gave rise to AL-type complexes with ginger OR, whereas βCD led to materials with limited solubility. Ginger OR was complexed with HPβCD by HME without significant change in gingerol and shogaol content. Additionally, thermogravimetric analysis (TGA) suggested higher volatile retention in HME complexes than in SL ones. Shogaol and gingerol solubility and dissolution significantly increased from SL and HME complexes compared with ginger OR. In turn, 1:2 OR/HPβCD HME complex showed higher 6-shogaol solubility than SL, associated with a gradual release. The carrageenan-induced pleurisy test showed that the anti-inflammatory activity of ginger OR was maintained after complexation with HPβCD. The complexes significantly decrease the levels of IL-1β and inhibit cell migration. HME complex showed performance equivalent to the positive control and superior to the SL material. Taken together, these results indicate that HME can be useful for promoting the molecular encapsulation of complex natural products that contain volatile and thermolabile substances. HME complexes showed better in vivo and in vitro performance than complexes prepared using the solvent-based method., (© 2022. Controlled Release Society.)

Endodontic microbial infections are still a challenge for an effective treatment for being biofilm-mediated and very refractory to conventional therapies. Biomechanical preparation and chemical irrigants cannot fully eradicate biofilms due to the anatomic structure of the root canal system. Instruments employed in biomechanical preparation and irrigants solution cannot reach the narrow and deepest portion of root canals, especially the apical thirds. In addition, aside from the dentin surface, biofilms can also infiltrate dentine tubules and periapical tissues, compromising treatment success. Therefore, different technologies have been investigated to achieve a more effective outcome in the control of endodontic infections. However, these technologies continue to face great difficulties in reaching the apical region and eradicating biofilms to avoid the recurrence of infection. Here, we present an overview of the fundamentals of endodontics infections and review technologies currently available for root canal treatment. We discuss them from a drug delivery perspective, highlighting each technology's strength to envision the best use of these technologies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

There is a growing interest in innovative products for eyebrow hair loss treatment with fewer adverse effects. Nevertheless, a fundamental formulation aspect of preventing the fragile skin from the ocular region from being irritated is that the formulations remain restricted to the application region and do not run off. Consequently, the methods and protocols in drug delivery scientific research must be adapted to fulfill such performance analysis demand. Thus, this work aimed to propose a novel protocol to evaluate the in vitro performance of a topical gel formulation with a reduced runoff for minoxidil (MXS) delivery to eyebrows. MXS was formulated with 16% poloxamer 407 (PLX) and 0.4% of hydroxypropyl methylcellulose (HPMC). The sol/gel transition temperature, viscosity at 25 °C, and formulation runoff distance on the skin were evaluated to characterize the formulation. The release profile and skin permeation were evaluated in Franz vertical diffusion cells for 12 h and compared to a control formulation (4% PLX and 0.7% HPMC). Then, the formulation's performance at promoting minoxidil skin penetration with minimum runoff was evaluated in a vertical custom-made permeation template (divided into three areas: superior, middle, and inferior). The MXS release profile from the test formulation was comparable to that from the MXS solution and the control formulation. There was also no difference in the MXS amount that penetrated the skin in the permeation experiments in Franz diffusion cells using the different formulations ( p > 0.05). However, the test formulation demonstrated a localized MXS delivery at the application site in the vertical permeation experiment. In conclusion, the proposed protocol could differentiate the test formulation from the control, attesting to its better performance in efficiently delivering MXS to the site of interest (middle third of application). The vertical protocol can be easily employed to evaluate other gels with a drip-free appeal.

This work aimed to evaluate poly(pseudo)rotaxanes (PPRs) potential for vaginal antifungal delivery. For this, PPRs containing terbinafine (TB) 2 % were obtained using two small surfactants, Kolliphor® RH40 and Gelucire® 48/16, and different α-cyclodextrin (α-CD) concentrations (5 and 10 %). PPRs were characterized by their physicochemical characteristics, irritation, and mucoadhesion capabilities. Formulations' performance was assessed in a vertical penetration model, which uses ex vivo entire porcine vagina. Conventional penetration experiments with excised vaginal tissue were performed as a control. Results showed all formulations were non-irritant according to the HET-CAM test. Furthermore, PPRs with 10 % αCD showed superior mucoadhesion (p < 0.05). Conventional horizontal penetration studies could not differentiate formulations (p > 0.05). However, PPRs with 10 % αCD presented a better performance in vertical ex vivo studies, achieving higher drug penetration into the vaginal mucosa (p < 0.05), which is probably related to the formulation's prolonged residence time. In addition, the antifungal activity of the formulations was maintained against Candida albicans and C. glabrata cultures. More importantly, the formulation's viscosity and drug delivery control had no negative impact on the antifungal activity. In conclusion, the best performance in a more realistic model evidenced the remarkable potential of PPRs for vaginal drug delivery., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Curcumin is a natural phenol found in the rhizome of Curcuma longa. It has been studied to treat several human carcinomas, such as melanomas and breast, head and neck, prostate, and ovary cancers. Here, we develop and validate a method for recovering curcumin from the skin layers and mucosa and selectively quantifying it, aiming to support permeation studies in developing topical formulations containing the natural compound. Recovery of curcumin from the stratum corneum, remaining skin, and mucosa was performed using ethanol, DMSO/ethanol, and DMSO, respectively, under mild stirring for specific periods. The separation of curcumin from the other curcuminoids, skin, and mucosa interferents was obtained using a C 18 column as a stationary phase. The mobile phase was composed of pH 3.0 phosphoric acid at 1.0 mmol/L and acetonitrile (47:53, v/v), which flowed at 1 mL min -1 . UV-Vis detection of curcumin was at 424 nm. The chromatographic method was selective, linear (r > 0.999), with a regression curve in the concentration range from 1.0 to 30.0 μg mL -1 , robust, precise, and accurate, with curcumin recovery rates higher than 95 ± 7 % from the mucosa, 82 ± 2 % from the stratum corneum, and 65 ± 10 % from the remaining skin. Finally, the method was successfully used in a skin permeation test performed with porcine skin and mucosa. The validated method is, therefore, suitable for the recovery and quantification of curcumin from the skin layers and mucosa, favoring the development of new topical formulations destined for these sites of administration., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Aesthetic perforations are often associated with health issues, such as itching, inflammation, or microbial infection. Accordingly, this work proposed a lacquer to be applied on the adornment accessory forming a film from which a proper drug is released. For this, lacquers were formulated containing three different permeation enhancers (limonene - LIM, propylene glycol - PG, and oleic acid - AO) combined according to a mixture design with a model anti-inflammatory natural drug (naringenin) and a soluble film-former polymer (polyvinyl alcohol). Formulations were characterized by physicochemical tests and in vitro and in vivo skin permeation studies. The lacquers were stable and provided a vectorized drug release. LIM, combined with one of the other permeation enhancers, showed a synergic effect, enhancing topical skin penetration in vitro by 53% while preventing permeation to the receptor medium. The in vivo evaluation of lacquers in rodent models showed these systems could provide higher levels of drug retention in the ear (166.4 ± 14.9 µg per ear for F4 and 174.9 ± 29.3 µg per ear for F5) compared to the control (109.2 ± 16.3 µg) without allowing its permeation into the bloodstream, confirming the local drug delivery. Moreover, the anti-inflammatory activity was achieved in the animal model developed for lacquer application on the earring, obtaining inhibition of ear swelling up to 40.8% ± 2.3 compared to the untreated ear. Thus, such an innovative lacquer proved a promising vehicle for treating affections caused by adornments, enhancing skin permeation while avoiding a systemic effect., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Cunha-Filho M reports financial support was provided by Foundation for Research Support of the Federal District., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Naringenin is a bioflavonoid mainly found in citrus fruits. It presents many pharmacological benefits, including a remarkable anti-inflammatory activity, but its oral bioavailability is poor. To overcome this drawback, this work proposes a transdermal administration of such bioflavonoid, considering its use in the chronic treatment of inflammatory conditions. For this, it aims to develop a chitosan-based film that guarantees a consistent transdermal delivery of the drug. First, naringenin's in vitro anti-inflammatory effect on T-cell proliferation was evaluated, followed by research on the modulation of gene expression for inflammatory factors in peripheral blood mononuclear cells. Chitosan films were then prepared and characterized. Afterward, naringenin release profile from a selected film was determined as well as the drug permeation across porcine skin provided by the film. Naringenin induced the expression of the anti-inflammatory factors IL-10 and TGF-β1 while inhibiting the expression of the pro-inflammatory cytokine IL-1β and limiting T-cell proliferation. The chitosan film was successfully developed, and the drug was progressively released to the physiological media following both first order and Korsmeyer-Peppas kinetics. When topically applied, the chitosan film guaranteed a constant and continuous diffusion of naringenin across the skin over 72 h. Indeed, the permeation flux of naringenin was 0.30 ± 0.01 µg/cm 2 /h, which means a concentration in the receptor solution 14-fold (p < 0.05) higher than that provided by the drug solution. Thus, the chitosan film represents a promising transdermal alternative for the long-term treatment of inflammatory conditions using naringenin., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Objectives: Three-dimensional printing (3DP) has opened the era of drug personalization, promising to revolutionize the pharmaceutical field with improvements in efficacy, safety and compliance of the treatments. As a result of these investigations, a vast therapeutic field has opened for 3DP-loaded drug devices with an anatomical fit. Along these lines, innovative dosage forms, unimaginable until recently, can be obtained. This review explores 3DP-engineered drug devices described in recent research articles, as well as in patented inventions, and even devices already produced by 3DP with drug-loading potential., Key Findings: 3D drug-loaded stents, implants and prostheses are reviewed, along with devices produced to fit hard-to-attach body parts such as nasal masks, vaginal rings or mouthguards. The most promising 3DP techniques for such devices and the complementary technologies surrounding these inventions are also discussed, particularly the scanners useful for mapping body parts. Health regulatory concerns regarding the new use of such technology are also analysed., Summary: The scenario discussed in this review shows that for wearable 3DP drug devices to become a tangible reality to users, it will be necessary to overcome the existing regulatory barriers, create new interfaces with electronic systems and improve the mapping mechanisms of body surfaces., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Royal Pharmaceutical Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Here, we verify the depigmenting action of Pouteria macrophylla fruit extract (EXT), incorporate it into a safe topical microemulsion and assess its effectiveness in a 3D pigmented skin model. Melanocytes-B16F10- were used to assess the EXT effects on cell viability, melanin synthesis, and melanin synthesis-related gene transcription factor expression, which demonstrated a 32% and 50% reduction of intra and extracellular melanin content, respectively. The developed microemulsion was composed of Cremophor EL ® /Span 80 4:1 ( w / w ), ethyl oleate, and pH 4.5 HEPES buffer and had an average droplet size of 40 nm (PdI 0.40 ± 0.07). Skin irritation test with reconstituted epidermis (Skin Ethic RHE TM ) showed that the formulation is non-irritating. Tyrosinase inhibition was maintained after skin permeation in vitro, in which microemulsion showed twice the inhibition of the conventional emulsion (20.7 ± 2.2% and 10.7 ± 2.4%, respectively). The depigmenting effect of the microemulsion was finally confirmed in a 3D culture model of pigmented skin, in which histological analysis showed a more pronounced effect than a commercial depigmenting formulation. In conclusion, the developed microemulsion is a promising safe formulation for the administration of cutite fruit extract, which showed remarkable depigmenting potential compared to a commercial formulation.

Naringenin is a flavonoid that can be found in citrus fruits (e.g., Citrus sp). This natural compound is known for its antioxidant activity, antitumor, and neuroprotective potential, also acting directly in controlling the inflammatory response. Topical and transdermal routes are attractive alternatives that could circumvent the low oral bioavailability. However, a simple analytical method capable of determining naringenin in skin layers is still demanded. Thus, this work aimed to validate a selective and straightforward chromatographic method for naringenin determination in skin permeation studies. The developed method uses a reversed-phase C 18 column as stationary phase and a mobile phase composed of methanol/phosphoric acid 0.01 M (65:35, v/v), eluted at a flow rate of 0.6 mL/min with detection at 290 nm. The method was linear (r 2  > 0.99) in a broad concentration range of 0.5-10.0 μg/mL, precise with an overall variation coefficient lower than 2%, and accurate with naringenin recovery from the skin layers higher than 85%. Additionally, the method was sensitive (LD = 0.10 μg/mL, LQ = 0.20 μg/mL), selective against skin matrices as well as naringenin degradation products, and robust regarding methodology parameters. Therefore, the method was suitable to be used in skin permeation studies employing naringenin., (Copyright © 2022 Elsevier B.V. All rights reserved.)

One of the challenges in developing three-dimensional printed medicines is related to their stability due to the manufacturing conditions involving high temperatures. This work proposed a new protocol for preformulation studies simulating thermal processing and aging of the printed medicines, tested regarding their morphology and thermal, crystallographic, and spectroscopic profiles. Generally, despite the strong drug-polymer interactions observed, the chemical stability of the model drugs was preserved under such conditions. In fact, in the metoprolol and Soluplus® composition, the drug's solubilization in the polymer produced a delay in the drug decomposition, suggesting a protective effect of the matrix. Paracetamol and polyvinyl alcohol mixture, in turn, showed unmistakable signs of thermal instability and chemical decomposition, in addition to physical changes. In the presented context, establishing protocols that simulate processing and storage conditions may be decisive for obtaining stable pharmaceutical dosage forms using three-dimensional printing technology., Competing Interests: The authors declare that there are no conflicts of interest., (© 2021 The Authors.)

Alopecia is a condition associated with different etiologies, ranging from hormonal changes to chemotherapy, that affects over 80 million people in the USA. Nevertheless, there are currently few FDA-approved drugs for topical treatment, and existing formulations still present skin irritation issues, compromising treatment adherence. This work aimed to develop a safe formulation based on nanostructured lipid carriers (NLC) that entrap an association of minoxidil and latanoprost and target drug delivery to the hair follicles. To do so, thermal techniques combined with FTIR were used to assess the chemical compatibility of the proposed drug association. Then, NLC with 393.5 ± 36.0 nm (PdI < 0.4) and +22.5 ± 0.2 mV zeta potential were produced and shown to entrap 86.9% of minoxidil and 99.9% of latanoprost efficiently. In vitro, the free drug combination was indicated to exert positive effects over human primary epidermal keratinocytes, supporting cell proliferation, migration and inducing the mRNA expression of MKI67 proliferation marker and VEGF - a possible effector for minoxidil-mediated hair growth. Interestingly, such a favorable drug combination profile was optimized when delivered using our NLC. Furthermore, according to the HET-CAM and reconstructed human epidermis assays, the nanoformulation was well tolerated. Finally, drug penetration was evaluated in vitro using porcine skin. Such experiments indicated that the NLC could be deposited preferentially into the hair follicles, causing a considerable increase in the penetration of the two drugs in such structures, compared to the control (composed of the free compounds) and generating a target-effect of approximately 50% for both drugs. In summary, present results suggest that hair follicle-targeted delivery of the minoxidil and latanoprost combination is a promising alternative to treat alopecia., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Transdermal administration of raloxifene hydrochloride (RLX)-loaded nanostructured lipid carriers (NLCs) has been proposed to circumvent its low oral bioavailability (2%). Preformulation studies were carried out to evaluate drug-excipient compatibility of various adjuvants commonly used for NLC preparation (waxes, cholesterol, compritol, gelucire, span 60, span 80, span 85, tween 80, poloxamer 188, oleic acid, caprylic/capric triglyceride, and castor oil). It was used differential scanning calorimetry (DSC), isothermal stress testing (IST), and solubility studies. The most promising excipients were chosen for NLC obtention, and full characterization was done, including in vitro skin permeation. DSC curves suggested drug-excipient interaction among some compounds, and the IST study showed incompatibility of RLX with waxes, compritol, cholesterol, span 60, and poloxamer 188. Solubility studies helped select gelucire, caprylic/capric triglyceride, span 80, and tween 80 for NLC production. Twelve NLCs were obtained (NLC1 to NLC12), but NLC7 and NLC8 were the most promising ones. In vitro release studies demonstrated that NLC7 and NLC8 were able to control RLX release (14.74 and 9.07% at 24 h, respectively) compared with the unloaded drug (> 90% at 24 h). Unloaded RLX did not permeate the diffusion cells' receptor medium and showed higher drug skin retention (11-fold) than RLX-loaded NLC. NLC reduced RLX skin retention, favoring drug permeation to deeper skin layers. NLC7 increased drug flux is 2.4-fold. NLC7 is a promising formulation for RLX transdermal drug delivery., (© 2021. Controlled Release Society.)

Polymeric nanocapsules have extensive application potential in medical, biological, and pharmaceutical fields, and, therefore, much research has been dedicated to their production. Indeed, production protocols and the materials used are decisive for obtaining the desired nanocapsules characteristics and biological performance. In addition to that, several technological strategies have been developed in the last decade to improve processing techniques and form more valuable nanocapsules. This review provides a guide to current methods for developing polymeric nanocapsules, reporting aspects to be considered when choosing appropriate materials, and discussing different ways to produce nanocapsules for superior performances., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Scarless skin regeneration is a challenge in regenerative medicine. Herein, we explore the regenerative potential of a Cupuaçu seed extract ( Theobroma grandiflorum ) to develop an innovative skin regeneration formulation based on chitosan-coated nanocapsules. Cupuaçu seed extract significantly stimulated cell proliferation and migration. A reparative gene expression profile could be verified following extract treatment, which included high levels of MKI67, a cellular proliferation marker, and extracellular matrix genes, such as ELN and HAS2, which code for elastin and hyaluronic acid synthase 2. Formulations with Cupuaçu seed extract successfully entrapped into nanocapsules (EE% > 94%) were developed. Uncoated or coated nanocapsules with low-molecular-weight chitosan presented unimodal size distribution with hydrodynamic diameters of 278.3 ± 5.0 nm (PDI = 0.18 ± 0.02) and 337.2 ± 2.1 nm (PDI = 0.27 ± 0.01), respectively. Both nanosystems were physically stable for at least 120 days and showed to be non-irritating to reconstructed human epidermis. Chitosan coating promoted active penetration into undamaged skin areas, which were still covered by the stratum corneum. In conclusion, the present study demonstrated for the first time the biotechnological potential of the frequently discarded Cupuaçu seed as a valuable pharmaceutical ingredient to be used in regenerative skin products.