Capsaicin-Cyclodextrin Complex Enhances Mepivacaine Targeting and Improves Local Anesthesia in Inflamed Tissues.

Acidic environments, such as in inflamed tissues, favor the charged form of local anesthetics (LA). Hence, these drugs show less cell permeation and diminished potency. Since the analgesic capsaicin (CAP) triggers opening of the TRPV1 receptor pore, its combination with LAs could result in better uptake and improved anesthesia. We tested the above hypothesis and report here for the first time the analgesia effect of a two-drug combination (LA and CAP) on an inflamed tissue. First, CAP solubility increased up to 20 times with hydroxypropyl-beta-cyclodextrin (HP-ß-CD), as shown by the phase solubility study. The resulting complex (HP-ß-CD-CAP) showed 1:1 stoichiometry and high association constant, according to phase-solubility diagrams and isothermal titration calorimetry data. The inclusion complex formation was also confirmed and characterized by differential scanning calorimetry (DSC), X-ray diffraction, and 1H-NMR. The freeze-dried complex showed physicochemical stability for at least 12 months. To test in vivo performance, we used a pain model based on mouse paw edema. Results showed that 2% mepivacaine injection failed to anesthetize mice inflamed paw, but its combination with complexed CAP resulted in pain control up to 45 min. These promising results encourages deeper research of CAP as an adjuvant for anesthesia in inflamed tissues and cyclodextrin as a solubilizing agent for targeting molecules in drug delivery.

Natural actives for wound healing: A review.

Nature has been a source of medicinal treatments for thousands of years, with the use of plants as prototypes for drug development and for the extraction of active compounds. Skin injuries occur regularly in everyday life, and the human skin has the ability to promote repair spontaneously under healthy conditions. However, some intrinsic and external factors may interfere with skins' natural ability, leading to nonhealing lesions and chronic wounds, which directly affect health and quality of life. Thus, attention should be given to this health problem, using an appropriated management when necessary. In this scenario, phytotherapy may be an option for cutaneous wound treatment, although further high-quality studies are needed to firmly establish the clinical efficacy of plants. This article reviews traditionally used natural actives for wound healing, highlighting their characteristics and mode of action.

Therapeutic l-asparaginase: upstream, downstream and beyond.

l-asparaginase (l-asparagine amino hydrolase, E.C.3.5.1.1) is an enzyme clinically accepted as an antitumor agent to treat acute lymphoblastic leukemia and lymphosarcoma. It catalyzes l-asparagine (Asn) hydrolysis to l-aspartate and ammonia, and Asn effective depletion results in cytotoxicity to leukemic cells. Microbial l-asparaginase (ASNase) production has attracted considerable attention owing to its cost effectiveness and eco-friendliness. The focus of this review is to provide a thorough review on microbial ASNase production, with special emphasis to microbial producers, conditions of enzyme production, protein engineering, downstream processes, biochemical characteristics, enzyme stability, bioavailability, toxicity and allergy potential. Some issues are also highlighted that will have to be addressed to achieve better therapeutic results and less side effects of ASNase use in cancer treatment: (a) search for new sources of this enzyme to increase its availability as a drug; (b) production of new ASNases with improved pharmacodynamics, pharmacokinetics and toxicological profiles, and (c) improvement of ASNase production by recombinant microorganisms. In this regard, rational protein engineering, directed mutagenesis, metabolic flux analysis and optimization of purification protocols are expected to play a paramount role in the near future.

Cytotoxicity of doxycycline effluent generated by the Fenton process.

This study aims at determining the Minimum Inhibitory Concentration with Escherichia coli ATCC 25922 and cytotoxicity to L929 cells (ATCC CCL-1) of the waste generated by doxycycline degradation by the Fenton process. This process has shown promise in this treatment thanks mainly to the fact that the waste did not show any relevant inhibitory effect on the test organism and no cytotoxicity to L-929 cells, thus demonstrating that the antibiotic properties were inactivated.

Self-assembly mucoadhesive beads of κ-carrageenan/sericin for indomethacin oral extended release.

Oral drug administration, especially when composed of mucoadhesive delivery systems, has been a research trend due to increased residence time and contact with the mucosa, potentially increasing drug bioavailability and stability. In this context, this study aimed to develop self-assembly mucoadhesive beads composed of blends of κ-carrageenan and sericin (κ-Car/Ser) loaded with the anti-inflammatory drug indomethacin (IND). We investigated the swelling, adhesion behaviour, and mechanical/physical properties of the beads, assessing their effects on cell viability, safety and permeation characteristics in both 2D and triple-culture model. The swelling ratio of the beads indicated pH-responsiveness, with maximum water absorption at pH 6.8, and strong mucoadhesion, increasing primarily with higher polymer concentrations. The beads exhibited thermal stability and no chemical interaction with IND, showing improved mechanical properties. Furthermore, the beads remained stable during accelerated and long-term storage studies. The beads were found to be biocompatible, and IND encapsulation improved cell viability (>70 % in both models, 79 % in VN) and modified IND permeation through the models (6.3 % for F5 formulation (κ-Car 0.90 % w/v | Ser 1.2 % w/v| IND 3.0 g); 10.9 % for free IND, p < 0.05). Accordingly, κ-Car/Ser/IND beads were demonstrated to be a promising IND drug carrier to improve oral administration while mitigating the side effects of non-steroidal anti-inflammatories.

Nanotechnology as a tool to overcome macromolecules delivery issues.

Nanocarriers can deliver drugs to specific organs or cells, potentially bridging the gap between a drug's function and its interaction with biological systems such as human physiology. The untapped potential of nanotechnology stems from its ability to manipulate materials, allowing control over physical and chemical properties and overcoming drug-related problems, e.g., poor solubility or poor bioavailability. For example, most protein drugs are administered parenterally, each with challenges and peculiarities. Some problems faced by bioengineered macromolecule drugs leading to poor bioavailability are short biological half-life, large size and high molecular weight, low permeability through biological membranes, and structural instability. Nanotechnology emerges as a promising strategy to overcome these problems. Nevertheless, the delivery system should be carefully chosen considering loading efficiency, physicochemical properties, production conditions, toxicity, and regulations. Moving from the bench to the bedside is still one of the major bottlenecks in nanomedicine, and toxicological issues are the greatest challenges to overcome. This review provides an overview of biotech drug delivery approaches, associated nanotechnology novelty, toxicological issues, and regulations.

Supramolecular Arrangement of Doxycycline with Sulfobutylether-ß-Cyclodextrin: Impact on Nanostructuration with Chitosan, Drug Degradation and Antimicrobial Potency.

Doxycycline (DX) is a well-established and broad-spectrum antimicrobial drug. However, DX has drawbacks, such as physicochemical instability in aqueous media and bacterial resistance. The inclusion of drugs in cyclodextrin complexes and their loading into nanocarriers can overcome these limitations. Thus, we studied the DX/sulfobutylether-ß-CD (SBE-ß-CD) inclusion complex for the first time and used it to reticulate chitosan. The resulting particles were evaluated by their physicochemical characteristics and antibacterial activity. DX/SBE-ß-CD complexes were characterized by nuclear magnetic resonance, infrared spectroscopy, thermal analysis, X-ray diffraction, and scanning electron microscopy (SEM), whereas DX-loaded nanoparticles were characterized by dynamic light scattering, SEM, and drug content. The partial inclusion of the DX molecule in CD happened in a 1:1 proportion and brought increased stability to solid DX upon thermal degradation. Chitosan-complex nanoparticles measured approximately 200 nm, with a narrow polydispersity and particles with sufficient drug encapsulation for microbiological studies. Both formulations preserved the antimicrobial activity of DX against Staphylococcus aureus, whereas DX/SBE-ß-CD inclusion complexes were also active against Klebsiella pneumoniae, indicating the potential use of these formulations as drug delivery systems to treat local infections.

k-Carrageenan/sericin-based multiparticulate systems: A novel gastro-resistant polymer matrix for indomethacin delivery.

This study aimed to develop a natural and multiparticulate carrier of k-carrageenan (k-Car) and sericin (Ser) for encapsulation of indomethacin (IND) in order to minimize gastrointestinal effects caused by immediate-release. Increasing the amount of IND in the formulations subtly reduced the entrapment efficiency (EE) and drug loading (DL) due to matrix saturation. Sericin was essential to improve EE and DL when compared to pure k-Car (EE > 90 % and DL > 47 %) with suitable particle sizes (1.3461 ± 0.1891-1.7213 ± 0.1586 mm). The incorporation and integrity of IND in the particles were confirmed by analytical techniques of HPLC, XRD, FTIR, and SEM. Additionally, the k-Car/Ser matrix was pH-responsive with low IND release at pH 1.2 and extended-release at pH 6.8. The Weibull model had an adequate fit to the experimental data with R2aju 0.950.99 and AIC 82.4-24.9, with curves in parabolic profile (b < 1) and indicative of a controlled drug-release mechanism by diffusion. Besides, k-Car/Ser/IND and placebo were not cytotoxic (cell viability > 85 % at 150-600 µM) for the Caco-2 cell line. Therefore, the polymeric matrix is gastro-resistant, stable, and biocompatible to carry indomethacin and deliver it to the intestinal environment.

Development and characterization of crosslinked k-carrageenan/sericin blend with covalent agents or thermal crosslink for indomethacin extended release.

Modified release of multiparticulate pharmaceutical forms is a key therapeutic strategy to reduce side effects and toxicity caused by high and repeated doses of immediate-release oral drugs. This research focused on the encapsulation of indomethacin (IND) in the crosslinked k-Car/Ser polymeric matrix by covalent and thermal methods to evaluate drug delivery modulation and properties of the crosslinked blend. Therefore, the entrapment efficiency (EE %), drug loading (DL %) and physicochemical properties of the particles were investigated. The particles presented a spherical shape and a rough surface with a mean diameter of 1.38-2.15 mm (CCA) and 1.56-1.86 mm (thermal crosslink). FTIR investigation indicated the presence of IDM in the particles and X-ray pattern showed the maintenance of crystallinity of IDM. The in vitro release in acidic medium (pH 1.2) and phosphate buffer saline solution (pH 6.8) was 1.23-6.81 % and 81-100 %, respectively. Considering the results, the formulations remained stable after 6 months. The Weibull equation was adequately fitted for all formulations and a diffusion mechanism, swelling and relaxation of chain were observed. IDM-loaded k-carrageenan/sericin/CMC increases cell viability (> 75 % for neutral red and > 81 % for MTT). Finally, all formulations present gastro-resistance, pH response and altered release and have the potential to be used as drug delivery careers.

Five decades of doxycycline: Does nanotechnology improve its properties?

Doxycycline (DX) is a well-established antimicrobial drug that has been used since 1967 to treat several diseases. This drug has a wide therapeutic range, acting as antibacterial, antiviral, antiparasitic, and anticancer agent, including its neuroprotective, anti-inflammatory, and wound healing effects. However, DX is unstable in the physiological environment, presenting poor cellular penetration and adverse effects related to gastrointestinal irritation. As for practically all antibiotics, bacteria can develop resistance to this drug. Pharmaceutical nanotechnology proved to be a promising strategy to overcome these drawbacks. Thus, this review addresses scientific studies regarding formulations of DX-loaded nanoparticles (DX-NPs) for therapy use. Formulations with different materials, manufacturing methods, and biomedical applications are described and discussed to understand NPs contribution for in vitro and in vivo DX performance.

Levofloxacin in nanostructured lipid carriers: Preformulation and critical process parameters for a highly incorporated formulation.

The first step of a successful nanoformulation development is preformulation studies, in which the best excipients, drug-excipient compatibility and interactions can be identified. During the formulation, the critical process parameters and their impact must be studied to establish the stable system with a high drug entrapment efficiency (EE). This work followed these steps to develop nanostructured lipid carriers (NLCs) to deliver the antibiotic levofloxacin (LV). The preformulation studies covered drug solubility in excipients and thorough characterization using thermal analysis, X-ray diffraction and spectroscopy. A design of experiment based on the process parameters identified nanoparticles with < 200 nm in size, polydispersity <= 0.3, zeta potential -21 to -24 mV, high EE formulations (>71 %) and an acceptable level of LV degradation products (0.37-1.13 %). To the best of our knowledge, this is the first time that a drug degradation is reported and studied in work on nanostructured lipids. LV impurities following the NLC production were detected, mainly levofloxacin N-oxide, a degradation product that has no antimicrobial activity and could interfere with LV quantification in spectrophotometric experiments. Also, the achievement of the highest EE in lipid nanoparticles than those described in the literature to date and the apparent protective action of NLC of entrapped-LV against degradation are important findings.

Nanotechnology-Based Dressings for Wound Management.

Wound healing is known to be a complicated and intricate process and commonly classified as chronic or acute. Patients with chronic wounds are of public health concern, and require more attention onto skin lesions, including atopic dermatitis. Despite being a natural process, healing can be impaired by existing chronic de diseases such as diabetes, for example. Recently, wound dressings based in nanotechnology systems have emerged as a viable option to improve the healing process. Current advances in nanotechnology-based systems to release growth factors and bioactive agents represent a great opportunity to develop new therapies for wound treatments. It is essential that healthcare professionals understand the key processes involved in the healing cascade, to maximize care with these patients and minimize the undesirable outcomes of non-healing wounds. Therefore, this review aims to summarize the healing process phases and provide a general overview of dressings based in nanotechnology using biomaterials for the release of active agents in wound site.

In vitro performance of free and encapsulated bromelain.

For centuries, bromelain has been used to treat a range of ailments, even though its mechanism of action is not fully understood. Its therapeutic benefits include enzymatic debridement of the necrotic tissues of ulcers and burn wounds, besides anti-inflammatory, anti-tumor, and antioxidant properties. However, the protease is unstable and susceptible to self-hydrolysis over time. To overcome the stability issues of bromelain, a previous study formulated chitosan-bromelain nanoparticles (C-B-NP). We evaluated the optimized nanoformulation for in vitro antioxidant, cell antiproliferative activities and cell migration/proliferation in the scratch assay, comparing it with free bromelain. The antioxidant activity of free bromelain was concentration and time-dependent; after encapsulation, the activity level dropped, probably due to the slow release of protein from the nanoparticles. In vitro antiproliferative activity was observed in six tumor cell lines for free protein after 48 h of treatment (glioma, breast, ovarian, prostate, colon adenocarcinoma and chronic myeloid leukemia), but not for keratinocyte cells, enabling its use as an active topical treatment. In turn, C-B-NP only inhibited one cell line (chronic myeloid leukemia) and required higher concentrations for inhibition. After 144 h treatment of glioma cells with C-B-NP, growth inhibition was equivalent to that promoted by the free protein. This last result confirmed the delayed-release kinetics of the optimized formulation and bromelain integrity. Finally, a scratch assay with keratinocyte cells showed that C-B-NP achieved more than 90% wound retraction after 24 h, compared to no retraction with the free bromelain. Therefore, nanoencapsulation of bromelain with chitosan conferred physical protection, delayed release, and wound retraction activity to the formulation, properties that favor topical formulations with a modified release. In addition, the promising results with the glioma cell line point to further studies of C-B-NP for anti-tumor treatments.

Protein drug delivery: current dosage form profile and formulation strategies.

Protein drugs present specific challenges to the maintenance of long-term stability, which can be accomplished by altering parameters of obtention, purification, molecule structure and formulation. As we believe, commercial formulations are undervalued; therefore, this review focuses on screening, categorising and discussing all formulations of protein drugs approved and not withdrawn by regulatory agencies from United States, Canada and Europe until mid-2018. Peptides (<50 amino acids) were not included to allow a more precise evaluation of choices for larger molecules. We extracted data from the DrugBank database, cross-checked it with the FDA purple book and supplemented it with patient information leaflets and papers. We further classified and discussed the entries according to protein function, drug delivery, route of administration and types of excipient (freeze-dried forms). In addition, alternative choices of excipients were discussed. Experimental work included here relates to targeting strategies with verified pharmacokinetics or in vivo effectiveness to identify physiologically relevant options. Although no single rule can be set for efficient protein formulation, our data help to better understand and optimise the choice for excipients and pharmaceutical dosage forms. For more information, see the Supplemental Data.

A mini-review on drug delivery through wafer technology: Formulation and manufacturing of buccal and oral lyophilizates.

A great number of patients have difficulty swallowing or needle fear. Therefore, buccal and orodispersible dosage forms (ODFs) represent an important strategy to enhance patient compliance. Besides not requiring water intake, swallowing or needles, these dosage forms allow drug release modulation. ODFs include oral lyophilizates or wafers, which present even faster disintegration than its compressed counterparts. Lyophilization can also produce buccal wafers that adhere to mucosa for sustained drug release. Due to the subject relevance and recent research growth, this review focused on oral lyophilizate production technology, formulation features, and therapy gains. It includes Critical Quality Attributes (CQA) and Critical Process Parameters (CPP) and discusses commercial and experimental examples. In sum, the available commercial products promote immediate drug release mainly based on biopolymeric matrixes and two production technologies. Therapy gains include substitution of traditional treatments depending on parenteral administration and patient preference over classical therapies. Experimental wafers show promising advantages as controlled release and drug enhanced stability. All compiled findings encourage the development of new wafers for several diseases and drug molecules.

Pharmacokinetic Aspects of Nanoparticle-in-Matrix Drug Delivery Systems for Oral/Buccal Delivery.

Oral route maintains its predominance among the ones used for drug delivery, especially when medicines are self-administered. If the dosage form is solid, therapy gains in dose precision and drug stability. Yet, some active pharmaceutical substances do not present the required solubility, permeability, or release profile for incorporation into traditional matrices. The combination of nanostructured drugs (nanoparticle [NP]) with these matrices is a new and little-explored alternative, which could bring several benefits. Therefore, this review focused on combined delivery systems based on nanostructures to administer drugs by the oral cavity, intended for buccal, sublingual, gastric, or intestinal absorption. We analyzed published NP-in-matrix systems and compared main formulation characteristics, pharmacokinetics, release profiles, and physicochemical stability improvements. The reported formulations are mainly semisolid or solid polymers, with polymeric or lipid NPs and one active pharmaceutical ingredient. Regarding drug specifics, most of them are poorly permeable or greatly metabolized. The few studies with pharmacokinetics showed increased drug bioavailability and, sometimes, a controlled release rate. From our knowledge, the gathered data make up the first focused review of these trendy systems, which we believe will help to gain scientific deepness and future advancements in the field.

Biodegradable nanocarriers coated with polymyxin B: Evaluation of leishmanicidal and antibacterial potential.

Most treatments of leishmaniasis require hospitalization and present side effects or parasite resistance; innovations in drug formulation/reposition can overcome these barriers and must be pursued to increase therapeutic alternatives. Therefore, we tested polymyxin B (polB) potential to kill Leishmania amazonensis, adsorbed or not in PBCA nanoparticles (PBCAnp), which could augment polB internalization in infected macrophages. PBCAnps were fabricated by anionic polymerization and analyzed by Dynamic Light Scattering (size, ζ potential), Nanoparticle Tracking Analysis (size/concentration), vertical diffusion cell (release rate), drug incorporation (indirect method, protein determination) and in vitro cell viability. Nanoparticles coated with polB (PBCAnp-polB) presented an adequate size of 261.5 ± 25.9 nm, low PDI and ζ of 1.79 ± 0.17 mV (stable for 45 days, at least). The 50% drug release from PBCAnp-polB was 6-7 times slower than the free polB, which favors a prolonged and desired release profile. Concerning in vitro evaluations, polB alone reduced in vitro amastigote infection of macrophages (10 µg/mL) without complete parasite elimination, even at higher concentrations. This behavior limits its future application to adjuvant leishmanicidal therapy or antimicrobial coating of carriers. The nanocarrier PBCAnp also presented leishmanicidal effect and surpassed polB activity; however, no antimicrobial activity was detected. PolB maintained its activity against E. coli, Pseudomonas and Klebsiella, adding antimicrobial properties to the nanoparticles. Thus, this coated drug delivery system, described for the first time, demonstrated antileishmanial and antimicrobial properties. The bactericidal feature helps with concomitant prevention/treatment of secondary infections that worst ulcers induced by cutaneous L. amazonensis, ultimately ending in disfiguring or disabling lesions.

Excipient-excipient interactions in the development of nanocarriers: an innovative statistical approach for formulation decisions.

Excipient interaction has become essential knowledge for rational formulation design of nanoparticles. Nanostructured lipid carriers (NLCs) include at least three types of excipient, which enhance excipient interaction possibilities and relevance. The present article introduces an alternative approach for evaluating a great number of excipients with few samples, using NLC as a model delivery system. This approach is based on two sequential experiments using Hall-2 experimental design and analysis of excipient interactions in respect to their physicochemical properties by multilevel statistics. NLCs were prepared using a hot emulsification-ultrasonication method with lidocaine and nine excipients (solid lipids, oils and surfactants). The evaluated parameters were z-average size (DLS), dispersity (DLS), zeta potential (electrophoretic mobility) and entrapment efficiency (HPLC). Cetyl palmitate, beeswax, castor oil, capric/caprylic acid and polysorbate 80 all presented larger effects amongst the studied factors as well as a clear pattern of synergistic interactions. Following the verified trends, we produced an optimized NLC that exhibited all desirable physicochemical characteristics and a modified drug release profile. Our results demonstrate the methodology's robustness, which can be applied to other nanoparticles and establish a cost-effective excipient evaluation.

Effect of Polysaccharide Sources on the Physicochemical Properties of Bromelain-Chitosan Nanoparticles.

Bromelain, a set of proteolytic enzymes potential pharmaceutical applications, was encapsulated in chitosan nanoparticles to enhance enzyme stability, and the effect of different chitosan sources was evaluated. Chitosan types (i.e., low molecular weight chitosan, chitosan oligosaccharide lactate, and chitosan from shrimp shells) produced nanoparticles with different physicochemical properties, however in all cases, particle size and zeta potential decreased, and polydispersity index increased after bromelain addition. Bromelain encapsulation was higher than 84% and 79% for protein content and enzymatic activity, respectively, with low molecular weight chitosan presenting the highest encapsulation efficiency. Nanoparticle suspension was also tested for accelerated stability and rheological behavior. For the chitosan-bromelain nanoparticles, an instability index below 0.3 was recorded and, in general, the loading of bromelain in chitosan nanoparticles decreased the cohesiveness of the final suspension.

Complexation of oxethazaine with 2-hydroxypropyl-ß-cyclodextrin: increased drug solubility, decreased cytotoxicity and analgesia at inflamed tissues.

OBJECTIVES: Oxethazaine (OXZ) is one of the few local anaesthetics that provides analgesia at low pH, but presents poor solubility, cytotoxicity and no parenteral formulations. To address these issues, we aimed to prepare OXZ host-guest inclusion complex with hydroxypropyl-beta-cyclodextrin (HP-ß-CD). METHODS: The inclusion complex was formed by co-solubilization, followed by a job plot analysis to determine stoichiometry of complexation and dialysis equilibrium analysis (based on UV/VIS absorption and fluorescence profiles of OXZ). Complex formation was confirmed by phase-solubility data, X-ray, Scanning Electron Microscopy and DOSY-1 H-NMR experiments. In vitro cytotoxicity was analysed by MTT test in 3T3 fibroblasts. In vivo analgesia was tested by Von Frey test (inflammatory wounds - rats). KEY FINDINGS: Oxethazaine complexed (1 : 1 molar ratio) with HP-ß-CD, as indicated by loss of OZX crystalline structure (X-ray) and strong host: guest interaction (NMR, K = 198/M), besides increased solubility. In vitro cell survival improved with the complex (IC50 OXZ = 28.9 µm, OXZ : HP-ß-CD = 57.8 µm). In addition, the complex (0.1% OXZ) promoted in vivo analgesia for the same time that 2% lidocaine/epinephrine did. CONCLUSION: Our results show that complexation improved physicochemical and biological properties of OXZ, allowing its application to inflamed tissues by parenteral routes.