Hydrogel of Thyme-Oil-PLGA Nanoparticles Designed for Skin Inflammation Treatment.

Thyme oil (THO) possesses excellent antibacterial and antioxidant properties which are suitable for skin inflammatory disorders such as acne vulgaris. However, THO is insoluble in water and its components are highly volatile. Therefore, these drawbacks may be overcome by its encapsulation in biodegradable PLGA nanoparticles (THO-NPs) that had been functionalized using several strategies. Moreover, cell viability was studied in HaCat cells, confirming their safety. In order to assess therapeutic efficacy against acne, bacterial reduction capacity and antioxidant properties were assessed. Moreover, the anti-inflammatory and wound-healing abilities of THO-NPs were also confirmed. Additionally, ex vivo antioxidant assessment was carried out using pig skin, demonstrating the suitable antioxidant properties of THO-NPs. Moreover, THO and THO-NPs were dispersed in a gelling system, and stability, rheological properties, and extensibility were assessed. Finally, the biomechanical properties of THO-hydrogel and THO-NP-hydrogel were studied in human volunteers, confirming the suitable activity for the treatment of acne. As a conclusion, THO has been encapsulated into PLGA NPs, and in vitro, ex vivo, and in vivo assessments had been carried out, demonstrating excellent properties for the treatment of inflammatory skin disorders.

Development and characterization of a poloxamer hydrogel composed of human mesenchymal stromal cells (hMSCs) for reepithelization of skin injuries.

Wound healing is a natural physiological reaction to tissue injury. Hydrogels show attractive advantages in wound healing not only due to their biodegradability, biocompatibility and permeability but also because provide an excellent environment for cell migration and proliferation. The main objective of the present study was the design and characterization of a hydrogel loaded with human mesenchymal stromal cells (hMSCs) for use in would healing of superficial skin injures. Poloxamer 407® was used as biocompatible biomaterial to embed hMSCs. The developed hydrogel containing 20 % (w/w) of polymer resulted in the best formulation with respect to physical, mechanical, morphological and biological properties. Its high swelling capacity confirmed the hydrogel's capacity to absorb wounds' exudate. LIVE/DEAD® assay confirm that hMSCs remained viable for at least 48 h when loaded into the hydrogels. Adding increasing concentrations of hMSCs-loaded hydrogel to the epithelium did not affect keratinocytes' viability and healing capacity and all wound area was closed in less than one day. Our study opens opportunities to exploit poloxamer hydrogels as cell carriers for the treatment of skin superficial wound.

Therapeutic Applications of Essential Oils from Native and Cultivated Ecuadorian Plants: Cutaneous Candidiasis and Dermal Anti-Inflammatory Activity.

Essential oils are a complex mixture of aromatic substances whose pharmacological actions, including antimicrobial, antioxidant, anticancer, and anti-inflammatory activities, have been widely reported. This study aimed to evaluate the anti-Candida and dermal anti-inflammatory activity of essential oils from native and cultivated Ecuadorian plants. Essential oils from Bursera graveolens, Dacryodes peruviana, Mespilodaphne quixos, and Melaleuca armillaris were isolated by hydrodistillation and were characterized physically and chemically. Its tolerance was analyzed by in vitro and in vivo studies. The antifungal activity was studied against Candida albicans, Candida glabrata, and Candida parapsilosis, whereas the anti-inflammatory effect was evaluated by a mouse ear edema model. The main compounds were limonene, α-phellandrene, (E)-methyl cinnamate, and 1,8-cineole, respectively. All essential oils showed high tolerability for skin application, antifungal activity against the three Candida strains, and anti-inflammatory efficacy by decreasing edema and overexpression of pro-inflammatory cytokines. Dacryodes peruviana essential oil showed the highest antifungal activity. On the other hand, Dacryodes peruviana and Melaleuca armillaris showed the greatest anti-inflammatory potential, decreasing edema by 53.3% and 65.25%, respectively, and inhibiting the overexpression of TNF-α, IL-8, IL-17A, and IL-23. The results suggest that these essential oils could be used as alternative therapies in the treatment of both cutaneous candidiasis and dermal inflammation.

In Vitro Approaches to Explore the Anticancer Potential of One Natural Flavanone and Four Derivatives Loaded in Biopolymeric Nanoparticles for Application in Topical Delivery Treatments.

The increasing number of skin cancer cases worldwide and the adverse side effects of current treatments have led to the search for new anticancer agents. In this present work, the anticancer potential of the natural flavanone 1, extracted from Eysenhardtia platycarpa, and four flavanone derivatives 1a-d obtained by different reactions from 1 was investigated by an in silico study and through cytotoxicity assays in melanoma (M21), cervical cancer (HeLa) cell lines and in a non-tumor cell line (HEK-293). The free compounds and compounds loaded in biopolymeric nanoparticles (PLGA NPs 1, 1a-d) were assayed. A structure-activity study (SAR) was performed to establish the main physicochemical characteristics that most contribute to cytotoxicity. Finally, ex vivo permeation studies were performed to assess the suitability of the flavanones for topical administration. Results revealed that most of the studied flavanones and their respective PLGA NPs inhibited cell growth depending on the concentration; 1b should be highlighted. The descriptors of the energetic factor were those that played a more important role in cellular activity. PLGA NPs demonstrated their ability to penetrate (Qp of 17.84-118.29 µg) and be retained (Qr of 0.01-1.44 g/gskin/cm2) in the skin and to exert their action for longer. The results of the study suggest that flavanones could offer many opportunities as a future anticancer topical adjuvant treatment.

Intrinsic Permeation and Anti-Inflammatory Evaluation of Curcumin, Bisdemethoxycurcumin and Bisdemethylcurcumin by a Validated HPLC-UV Method.

Curcumin shows anti-inflammatory activity, and it has been widely investigated for neurodegenerative diseases, adjuvant treatment in AIDS and antitumor activity against different tumors, among other activities. The goal of this work was to evaluate the capacity of curcumin and its derivatives (bisdemethoxycurcumin and bisdemethylcurcumin) in preventing the irritant effects of topically applied xylol and to assess the intrinsic capacity of curcuminoids in permeating human skin by ex vivo permeation tests. Its secondary goal was to validate an HPLC method to simultaneously determine the curcuminoids in the samples from the ex vivo permeation studies and drug extraction from the skin. Curcuminoid quantification was performed using an RP-C18 column, at isocratic conditions of elution and a detection wavelength of 265 nm. The method was specific with a suitable peak resolution, as well as linear, precise, and accurate in the range of 0.195-3.125 µg/mL for the three curcuminoids. Bisdemethylcurcumin showed the greatest permeation through the human skin, and it was the curcuminoid that was most retained within the human skin. The anti-inflammatory activity of the curcuminoids was evaluated in vivo using a xylol-induced inflammation model in rats. Histological studies were performed to observe any changes in morphology at the microscopic level, and these three curcuminoids were found to be respectful within the skin structure. These results show that these three curcuminoids are suitable for anti-inflammatory formulations for dermal applications, and they can be properly quantified using HPLC-UV.

Characterization and In Vivo Anti-Inflammatory Efficacy of Copal (Dacryodes peruviana (Loes.) H.J. Lam) Essential Oil.

Essential oils are natural aromatic substances that contain complex mixtures of many volatile compounds frequently used in pharmaceutical and cosmetic industries. Dacryodes peruviana (Loes.) H.J. Lam is a native species from Ecuador whose anti-inflammatory activity has not been previously reported, thus the aim of this study was to evaluate the anti-inflammatory activity of D. peruviana essential oil. To that end, essential oil from D. peruviana fruits was isolated by hydrodistillation and characterized physically and chemically. The tolerance of the essential oil was analyzed by cytotoxicity studies using human keratinocytes. The anti-inflammatory activity was evaluated by an arachidonic acid-induced edema model in mouse ear. The predominant compounds in D. peruviana essential oil were α-phellandrene, limonene, and α-pinene, with the three compounds reaching approximately 83% of the total composition. Tolerance studies showed high biocompatibility of this essential oil with human keratinocytes. In vivo studies demonstrated a moisturizing effect and an alleviation of several events occurred during the inflammatory process after topical treatment with D. peruviana essential oil such as decline in skin edema; reduction in leukocytic infiltrate; and decrease in inflammatory cytokines TNFα, IL-8, IL-17A, and IL-23. Therefore, this essential oil could be an attractive treatment for skin inflammation.

Quality by Design of Pranoprofen Loaded Nanostructured Lipid Carriers and Their Ex Vivo Evaluation in Different Mucosae and Ocular Tissues.

Transmucosal delivery is commonly used to prevent or treat local diseases. Pranoprofen is an anti-inflammatory drug prescribed in postoperative cataract surgery, intraocular lens implantation, chorioretinopathy, uveitis, age-related macular degeneration or cystoid macular edema. Pranoprofen can also be used for acute and chronic management of osteoarthritis and rheumatoid arthritis. Quality by Design (QbD) provides a systematic approach to drug development and maps the influence of the formulation components. The aim of this work was to develop and optimize a nanostructured lipid carrier by means of the QbD and factorial design suitable for the topical management of inflammatory processes on mucosal tissues. To this end, the nanoparticles loading pranoprofen were prepared by a high-pressure homogenization technique with Tween 80 as stabilizer and Lanette® 18 as the solid lipid. From, the factorial design results, the PF-NLCs-N6 formulation showed the most suitable characteristics, which was selected for further studies. The permeability capacity of pranoprofen loaded in the lipid-based nanoparticles was evaluated by ex vivo transmucosal permeation tests, including buccal, sublingual, nasal, vaginal, corneal and scleral mucosae. The results revealed high permeation and retention of pranoprofen in all the tissues tested. According to the predicted plasma concentration at the steady-state, no systemic effects would be expected, any neither were any signs of ocular irritancy observed from the optimized formulation when tested by the HET-CAM technique. Hence, the optimized formulation (PF-NLCs-N6) may offer a safe and attractive nanotechnological tool in topical treatment of local inflammation on mucosal diseases.

Polymeric Nanoparticles and Chitosan Gel Loading Ketorolac Tromethamine to Alleviate Pain Associated with Condyloma Acuminata during the Pre- and Post-Ablation.

This study describes the preparation and evaluation of two formulations, a hydrogel and a nanostructured system, containing ketorolac tromethamine as an anti-inflammatory agent for the local therapy against the inflammatory process derived from the surgical excision of Condyloma acuminata. Both formulations were physicochemically characterized. In vitro release profiles show that the nanoparticles release 92% ± 2.3 of the total ketorolac tromethamine encapsulated, while the chitosan gel releases 18.6% ± 0.2. The ex vivo permeation and distribution through human skin were also assayed and was observed how the main amount of ketorolac tromethamine is retained in the epidermis. In vivo studies were accomplished to evaluate the anti-inflammatory efficacy in mice which also involved the histological analysis to confirm the in vivo results. The nanoparticles present a significantly higher anti-inflammatory efficacy than chitosan gel. The tolerability of developed formulations was assessed by monitoring the biomechanical properties of the skin before and after application of both formulations. No statistical differences in trans-epidermal water loss and skin hydration with respect to the basal values were observed and the formulations exhibited higher anti-inflammatory activity compared to a reference ketotorlac tromethamine solution. Therefore, it can be concluded that both formulations can be proposed as outstanding candidates for offering a local anti-inflammatory therapeutical tool with potential clinical application.

HPV Lesions and Other Issues in the Oral Cavity Treatment and Removal without Pain.

Due to different oral and dental conditions, oral mucosa lesions such as those caused by the human papilloma virus and temporomandibular joint pathologies often have to be treated by surgical, ablative or extractive procedures. The treatment and control of pain and inflammation during these procedures is essential to guarantee the patient's well-being. For the foregoing reason, a hydrogel based on sodium alginate and hyaluronic acid containing 2% of ketorolac tromethamine has been developed. We characterized it physically, mechanically and morphologically. The rheological results suggest that the formulation can be easily and gently applied. Ex vivo permeation studies show that Ketorolac Tromethamine is able to penetrate through the buccal and sublingual mucosae, in addition to being retained in the mucosae's structure. Through an in vitro test, we were able to evaluate the role that saliva plays in the bioavailability of the drug, observing that more than half of the applied dose is eliminated in an hour. The histological and cytotoxic studies performed on pigs in vivo showed the excellent safety profile of the formulation, as well as its high tolerability. In parallel, a biomimetic artificial membrane (PermeaPad®) was evaluated, and it showed a high degree of correlation with the oral and sublingual mucosa.

Topical Mucoadhesive Alginate-Based Hydrogel Loading Ketorolac for Pain Management after Pharmacotherapy, Ablation, or Surgical Removal in Condyloma Acuminata.

Condyloma acuminata is an infectious disease caused by the human papilloma virus (HPV) and one of the most common sexually transmitted infections. It is manifested as warts that frequently cause pain, pruritus, burning, and occasional bleeding. Treatment (physical, chemical, or surgical) can result in erosion, scars, or ulcers, implying inflammatory processes causing pain. In this work, a biocompatible topical hydrogel containing 2% ketorolac tromethamine was developed to manage the painful inflammatory processes occurring upon the removal of anogenital condylomas. The hydrogel was physically, mechanically, and morphologically characterized: it showed adequate characteristics for a topical formulation. Up to 73% of ketorolac in the gel can be released following a one-phase exponential model. Upon application on human skin and vaginal mucosa, ketorolac can permeate through both of these and it can be retained within both tissues, particularly on vaginal mucosa. Another advantage is that no systemic side effects should be expected after application of the gel. The hydrogel showed itself to be well tolerated in vivo when applied on humans, and it did not cause any visible irritation. Finally, ketorolac hydrogel showed 53% anti-inflammatory activity, suggesting that it is a stable and suitable formulation for the treatment of inflammatory processes, such as those occurring upon chemical or surgical removal of anogenital warts.

Validation of an Ex Vivo Permeation Method for the Intestinal Permeability of Different BCS Drugs and Its Correlation with Caco-2 In Vitro Experiments.

The absorption study of drugs through different biological membranes constitutes an essential step in the development of new pharmaceutical dosage forms. Concerning orally administered forms, methods based on monolayer cell culture of Caco-2 (Caucasian colon adenocarcinoma) have been developed to emulate intestinal mucosa in permeability studies. Although it is widely accepted, it has disadvantages, such as high costs or high technical complexity, and limitations related to the simplified structure of the monolayer or the class of molecules that can be permeated according to the transport mechanisms. The aim of this work was to develop a new ex vivo methodology which allows the evaluation of the intestinal apparent permeability coefficient (Papp) while using fewer resources and to assess the correlation with Caco-2. To this end, pig (Sus scrofa) duodenum segments were mounted in Franz diffusion cells and used to permeate four different drugs: ketorolac tromethamine (Kt), melatonin (Mel), hydrochlorothiazide (Htz), and furosemide (Fur). No statistically significant differences (p > 0.05) were observed corelating Papp values from Franz diffusion cells and Caco-2 cell experiments for Kt, Htz, and Fur. However, there were statistically significant differences (p < 0.05) correlating Papp values and Mel. The difference is explained by the role of Mel in the duodenal epithelial paracellular permeability reduction. Ex vivo permeation may be an equivalent method to Caco-2 for drugs that do not produce intestinal membrane phenomena that could affect absorption.

Development of a mucoadhesive delivery system for control release of doxepin with application in vaginal pain relief associated with gynecological surgery.

The main purpose of this study was to develop a semisolid mucoadhesive formulation for the non-invasive vaginal administration of doxepin (DOX) for relief of pain derived from the scarring process after surgery. An orafix® platform loading DOX was tested for adequate stability, rheology and vaginal mucoadhesion capacity. The formulation exhibited appropriate pH and was microbiologically stable. The rheological studies confirmed its pseudoplastic and thixotropic nature with prevalence of the elastic behavior component over the viscous one. Appropriate syringeability and spreadability results were also confirmed. Different experiments showed adequate mucoadhesion capacity even in the presence of simulated vaginal fluid. Finally, DOX release, permeation and retention in vaginal mucosa studies were also accomplished with promising results. DOX release kinetics followed the modified Higuchi model and the permeation studies did not render such high values as to suggest potential systemic absorption which could lead to undesirable systemic side effects. Therefore, we can hypostatize that the proposed formulation may assist to fill in the therapeutic gap regarding pure pain relief at local level in vagina.

Cytotoxic Evaluation of (2S)-5,7-Dihydroxy-6-prenylflavanone Derivatives Loaded PLGA Nanoparticles against MiaPaCa-2 Cells.

The search for new alternatives for the prevention and treatment of cancer is extremely important to minimize human mortality. Natural products are an alternative to chemical drugs, since they are a source of many potential compounds with anticancer properties. In the present study, the (2S)-5,7-dihydroxy-6-prenylflavanone (semi-systematic name), also called (2S)-5,7-dihydroxy-6-(3-methyl-2-buten-1-yl)-2-phenyl-2,3-dihydro-4H-1-Benzopyran-4-one (CAS Name registered) (1) was isolated from Eysenhardtia platycarpa leaves. This flavanone 1 was considered as the lead compound to generate new cytotoxic derivatives 1a, 1b, 1c and 1d. These compounds 1, 1a, 1b, 1c, and 1d were then loaded in nanosized drug delivery systems such as polymeric nanoparticles (NPs). Small homogeneous spherical shaped NPs were obtained. Cytotoxic activity of free compounds 1, 1a, 1b, 1c, and 1d and encapsulated in polymeric NPs (NPs1, NPs1a, NPs1b, NPs1c and NPs1d) were evaluated against the pancreatic cancer cell line MiaPaCa-2. The obtained results demonstrated that NPs1a and NPs1b exhibited optimal cytotoxicity, and an even higher improvement of the cytotoxic efficacy was exhibited with the encapsulation of 1a. Based on these results, NPs1a were proposed as promising anticancer agent candidates.

Development of biomedical 5-fluorouracil nanoplatforms for colon cancer chemotherapy: Influence of process and formulation parameters.

In the present investigation solvent displacement or nanoprecipitation, and emulsion/solvent evaporation methods were utilized to optimize poly(D,L-lactide-co-glycolide) nanoparticles for the vehiculization of the 5-fluorouracil. Formulation components from both the aqueous and organic phases, as well as, operating conditions were varied. Particles were characterized in terms of particle size and morphology, electrical properties, rheology, drug loading, stability, and drug release. Furthermore, in vitro cytotoxicity on human colon cells and different colon carcinoma cells was evaluated. Four types of nanoparticles were selected for drug loading, revealing differences between variables. Low viscosity values and their Newtonian behavior could assure the suitability of the nanoformulation for the intravenous route of administration. The greatest drug entrapment efficiency and best stability was achieved when the chemotherapeutic agent was incorporated into the internal aqueous phase of particles prepared by double emulsion/solvent evaporation. However, a more sustained drug release at pH 7.4 was possible when 5-fluorouracil was added to the external aqueous phase. These were the nanoformulations reporting the greatest antiproliferative efficacy compared with the free drug. The nanocarrier can optimize the antitumor activity of 5-fluorouracil, thus being a potential nanotool against colon cancer.

Development of a buccal doxepin platform for pain in oral mucositis derived from head and neck cancer treatment.

This study describes the development of semisolid formulations containing doxepin (DOX) for pain relief in oral mucositis, frequently related to chemotherapy and/or radiotherapy treatments in patients with head and neck cancer. Chemical permeation enhancers were evaluated and selected according to the results obtained from rheological studies, drug release, and drug permeation and retention through buccal mucosa. Finally, the selected formulation was compared in vivo, with a reference DOX mouthwash, whose clinical efficacy had been previously reported. The obtained findings showed that an orabase® platform loading transcutol® (10%) and menthol (5%) for the buccal vehiculization of DOX exhibited a decreased elastic and viscous behavior improving its application. The main drug release mechanism could be considered as diffusion according to Higuchi model. Obtained DOX permeation rates were considered optimal for an analgesic effect and far below to an antidepressant activity. Similar in vivo plasma concentrations were found for the semisolid formulation and the reference mouthwash. However, DOX amounts retained in the mucosa of animals for the semisolid formulation were higher than the reference, which let us hypostatize even stronger potential local therapeutic effect with additional advantages such as, mucoadhesive properties, absence of alcohol, some degree of freshness, as well as, drug palatability improvement.

Design and elaboration of freeze-dried PLGA nanoparticles for the transcorneal permeation of carprofen: Ocular anti-inflammatory applications.

This work aimed the design and development of poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) for the ocular delivery of Carprofen (CP) by a central rotatable composite design 2(3)+ star. NPs showed adequate size for ocular administration (189.50 ± 1.67 nm), low polydispersity (0.01 ± 0.01), negative charge surface (-22.80 ± 0.66 mV) and optimal entrapment efficiency (74.70 ± 0.95%). Physicochemical analysis confirmed that CP was dispersed inside the NPs. The drug release followed a first order kinetic model providing greater sustained CP release after lyophilization. Ex vivo permeation analysis through isolated rabbit cornea revealed that a sufficient amount of CP was retained in the tissue avoiding excessive permeation and thus, potential systemic levels. Ex vivo ocular tolerance results showed no signs of ocular irritancy, which was also confirmed by in vivo Draize test. In vivo ocular anti-inflammatory efficacy test confirmed an optimal efficacy of NPs and its potential application in eye surgery.

Stability studies of binary and ternary mixtures containing morphine, midazolam, levomepromazine and hyoscine butylbromide for parenteral administration.

OBJECTIVES: [corrected] Parenteral (intravenous or subcutaneous) administration is routinely used in palliative medicine because patients are not able to take drugs orally. To avoid excessive injections, several drugs are usually given in the same dose, but the stability of these drugs when mixed is not always known. The aim of this study was to evaluate the stability of several mixtures of drugs (morphine, midazolam, levomepromazine and hyoscine butylbromide) kept under different storage conditions. METHODS: Stability was evaluated on the basis of percentage of drug remaining, pH, change of colour and gas or precipitate formation. KEY FINDINGS: The most notable results of the study showed that levomepromazine is rapidly degraded in 0.9% NaCl in all cases, and at high concentrations, morphine can precipitate when stored at 4°C. CONCLUSIONS: Mixtures containing levomepromazine are rapidly degraded under experimental conditions.