Penetration Enhancing Properties Research Articles

Development of transferosomes for topical ocular drug delivery of curcumin

Transferosomes (TFS) are ultra-deformable elastic bilayer vesicles that have previously been used to enhance gradient driven penetration through the skin. This study aimed to evaluate the potential of TFS for topical ocular drug delivery and to compare their penetration enhancing properties in different ocular tissues. Curcumin-loaded TFS were prepared using Tween 80 as the edge activator. Drug release and precorneal retention of the TFS were evaluated in vitro, while their ocular biocompatibility and bioavailability were evaluated ex vivo using a curcumin solution in medium chain triglycerides as the oily control. The TFS had a narrow size distribution with a particle size less than 150nm and an entrapment efficiency greater than 99.96%. Burst release from the TFS was minimal and the formulation showed good corneal biocompatibility. Moreover, enhanced corneal and conjunctival drug penetration with significantly greater and deeper drug delivery was observed with TFS. TFS offer a promising platform for ocular delivery of hydrophobic drugs. This study, for the first time, elucidates the effect of tissue morphology and osmotic gradients on drug penetration in different ocular tissues.

Investigation of the synthesis, gelation potential, and drug-loading capacities of two novel amides.

This study consists of four steps. In the first, two different biocompatible organogelators were synthesized, starting with the L-isoleucine amino acid to obtain amide compounds. In the second step, the gelation potential of synthesized organogelators with fatty acid esters and organic solvents was investigated. These esters were chosen as gelation liquids due to their biocompatibility and also their penetration-enhancing properties when the drug is administered via the skin. After the minimum gel concentrations (MGCs) of the organogelators were determined, the melting point of gel T g was found, and then, ΔH g gelation enthalpy values were found by means of the Van't Hoff equation. In addition to the gelation abilities and capacities of the organogelators being thus synthesized, their thermal stabilities were also determined. In the third stage of the study, the network which occurred during the formation of the gels was screened by an SEM device, and their characterizations were determined. In the study's fourth stage, the gels were loaded with ibuprofen and naproxen-known for their non-steroidal anti-inflammatory and analgesic effects-and their drug-loading capacities were thus determined.

An Overview of Transferosomes: A Transdermal Drug Delivery System

A lipid bilayer including phospholipids, an edge activator, and an ethanol/aqueous core makes up transferosomes, often referred to as transferosomes, which are ultra-deformable vesicles for transdermal applications. Compared to oral and needle-based methods, this approach has a number of benefits, including self-administration, non-invasiveness, significantly reduced hepatic clearance of the medication, and increased patient compliance. The primary reason for the development of various drug delivery systems was that due to the first pass metabolism, adverse and side effects, non-patient compliance and invasive procedures, the efficient therapeutic outcomes. The advantage of transferosomes is they are barely invasive without the first pass metabolism. Transferosomes also has several advantages than liposomes due to the active surfactant properties. Due to its penetration enhancer properties, it enables the drug molecule to penetrate into the skin via the stratum corneum than other formulations. So, more research works are encouraged with respect to tranferosomes in order to formulate various new drugs in this type of drug delivery system.

Non-Invasive Transdermal Delivery of Antisense Oligonucleotides with Biocompatible Ionic Liquids.

Nucleic acid drugs, including antisense oligonucleotides (ASOs), have received considerable attention as novel therapeutics for the treatment of intractable diseases. Despite their potential benefits, ASOs are currently administered via injection, which can negatively impact patient quality of life because of the prevalence of severe injection site reactions. Non-invasive transdermal administration of ASOs is desirable but highly challenging owing to the strong barrier imposed by the stratum corneum, which only permits the penetration of small molecules under 500 Da. For ASOs to exert their antisense effect, they must traverse the negatively charged cell membrane and reach the cytoplasm. In this study, we used the solid-in-oil (S/O) dispersion technology to facilitate the skin permeation of ASOs by coating the drug with a hydrophobic surfactant molecule, specifically lipid-based ionic liquid (IL) surfactants with high biocompatibility and transdermal penetration-enhancing properties. To induce the antisense effect, it was important to achieve simultaneous transdermal delivery and intracellular entrapment of ASOs. In vitro investigations indicated that the newly prepared IL-S/O enhanced the transdermal penetration and intracellular delivery of ASOs, thus inhibiting mRNA translation of the target TGF-β. In addition, in vivo investigations of tumor-bearing mice suggested that the anti-tumor effect of the IL-S/O was similar to that of injection. This study demonstrates the potential of non-invasive transdermal delivery carriers based on biocompatible ILs, which can be applied to a variety of nucleic acid drugs.

Development and Evaluation of an FDM Printed Nasal Device for CPZ Solid Nanoparticles.

Nasal drug delivery has been a focus of scientific interest for decades. A number of drug delivery systems and devices are available and have been highly successful in providing better and more comfortable therapy. The benefits of nasal drug delivery are not in question. The nasal surface provides an excellent context for the targeted delivery of active substances. In addition to the large nasal surface area and intensive absorption, the active substances delivered through the nose overcome the blood-brain barrier and can be delivered directly to the central nervous system. Formulations for nasal administration are typically solutions or liquid dispersed systems such as emulsions or suspensions. Formulation techniques for nanostructures have recently undergone intensive development. Solid-phase heterogeneous dispersed systems represent a new direction in pharmaceutical formulations. The wide range of possible examples and the variety of excipients allow for the delivery of a wide range of active ingredients. The aim of our experimental work was to develop a solid drug delivery system that possesses all of the above-mentioned advantageous properties. In developing solid nanosystems, we not only exploited the advantages of size but also the adhesive and penetration-enhancing properties of excipients. During formulation, several amphiphilic compounds with adhesion properties and penetration enhancing effects were incorporated. We used chlorpromazine (CPZ), which is mainly used in the treatment of psychotic disorders such as schizophrenia and bipolar disorder. Chlorpromazine has been previously investigated by our team in other projects. With the availability of previous methods, the analytical characterization of the drug was carried out effectively. Due to the frequent and severe side effects of the drug, the need for therapeutic dose reduction is indisputable. In this series of experiments, we succeeded in constructing drug delivery systems. Finely divided Na nanoparticles were formed using a Büchi B90 nanospray dryer. An important step in the development of the drug carrier was the selection of suitable inert carrier compounds. Particle size determination and particle size distribution analysis were performed to characterize the prepared nanostructures. As safety is the most important aspect of any drug formulation, all components and systems were tested with different biocompatibility assays. The tests performed demonstrated the safe applicability of our systems. The bioavailability of chlorpromazine was studied as a function of the ratio of the active ingredient administered nasally and intravenously. As described above, most nasal formulations are liquids, but our system is solid, so there is currently no tool available to accurately target this system. As a supplement of the project, a nasal dosing device was developed, corresponding to the anatomical structure; a prototype of the device was made using 3D FDM technology. Our results lay the foundation for the design and industrial scaling of a new approach to the design and production of a high-bioavailability nasal medicinal product.

Influence of the Size and Charge of Carbon Quantum Dots on Their Corneal Penetration and Permeation Enhancing Properties.

Reaching the corneal endothelium through the topical administration of therapeutic drugs remains a challenge in ophthalmology. Besides, endothelial cells are not able to regenerate, and diseases at this site can lead to corneal blindness. Targeting the corneal endothelium implies efficient penetration through the three corneal layers, which still remains difficult for small molecules. Carbon quantum dots (CQDs) have demonstrated great potential for ocular nanomedicine. This study focuses on the corneal penetration abilities of differently charged CQDs and their use as permeation enhancers for drugs. Excised whole bovine eyes were used as an ex vivo model to investigate corneal penetration of CQDs derived from glucosamine using β-alanine, ethylenediamine, or spermidine as a passivation agent. It was found that negatively charged CQDs have limited corneal penetration ability, while positively charged CQDs derived from glucosamine hydrochloride and spermidine (CQD-S) penetrate the entire corneal epithelium all the way down to the endothelium. CQD-S were shown to enhance the penetration of FITC-dextran 150 kDa, suggesting that they could be used as efficient penetration enhancers for therapeutic delivery to the corneal endothelium.

A safe bioadhesive system for topical delivery of combined antimicrobials in treatment of skin infections in veterinary medicine

A safe bioadhesive system for topical delivery of combined antimicrobials in treatment of skin infections in veterinary medicine

The role of excipients in promoting topical and transdermal delivery: Current limitations and future perspectives

Topical and transdermal delivery has historically offered an attractive and non-invasive route for administration of medicines. However, human skin is known to be a remarkably good barrier to the permeation of substances. The majority of dermatological drug products have been reported to only deliver a portion of the total dose applied, often resulting in low drug bio-availability at the site of action inside the skin. This insufficient formulation performance, coupled with the fact that percutaneous delivery is heavily influenced by the innate physicochemical properties of the active, pose limitations on effective treatment and prevention of diseases by using solely topical formulations. Generally, it is known that the rate and the extent of drug delivery to and through the skin is highly dependent on the formulation components. This work highlights the importance of the vehicle for the design of efficacious skin products, discusses current limitations in dermal delivery and explores recent advances for overcoming these challenges. Novel materials with penetration enhancing properties and innovative formulation strategies are also explored, together with future perspectives and outlooks. The emphasis here is on studies focused on passive skin transport because of clinical limitations associated with disrupting the skin barrier by physical methods. This information is believed to aid in the design and optimization of dermatological drug products for topical and transdermal delivery of actives.

Development and Validation of an HPLC Method for Simultaneous Determination of Miconazole Nitrate and Chlorhexidine Digluconate in Chitosan-Based Gel Formulations

Miconazole nitrate (MN) and chlorhexidine digluconate (CHX) are the commonly used antimicrobials for topical treatment of dermal infections. Combination of antimicrobials has been investigated to enhance the efficacy of the treatment. Gel formulations based on bioadhesive polymers are preferred for delivery of these drugs. Chitosan is a promising bioadhesive polymer due to its penetration enhancing, antimicrobial and tissue healing properties. Yet, most of the gel-based formulations present analytical challenges during testing the drug content. It was aimed to develop an HPLC method for simultaneous determination of MN and CHX in chitosan-based gel formulations. Different solvent combinations were investigated for extraction of drugs from the gels. HPLC conditions such as mobile phase, flow rate, run time, column temperature and wavelength were explored. The method was validated according to ICH guideline Q2(R1). MN and CHX were extracted in solvent composition same with the mobile phase. The method was employed on ACE-C8 column at 40°C by isocratic elution using the mobile phase consisting of methanol:phosphate (75:25 v/v) buffer (containing triethylamine). Flow rate was 1 mL/min. The drugs were detected at 254 nm (CHX) and 230 nm (MN). Linearity was obtained between 5 to 80 μg/mL for both drugs. LOD and LOQ obtained for CHX was 1.61 and 1.06, for MN: 4.87 and 3.21 µg/mL, respectively. A new validated HPLC method was developed for simultaneous determination of CHX and MN in chitosan-based gels, with 98 to 102% recovery, without any interference with the excipients.

Enhancement of Skin Permeation and Penetration of β-Arbutin Fabricated in Chitosan Nanoparticles as the Delivery System

Background: There has been an increase in demand for cosmetic skin-whitening products with efficacy toward lightening skin tone. β-arbutin is an inhibitor of tyrosinase enzyme activity within the skin’s melanocytes, and so has shown considerable promise as a skin-lightening agent. It is, however, both hydrophilic and hygroscopic, which hinders its penetration of the skin to reach these melanocytes. Chitosan (CS) possesses considerable penetration-enhancing properties when utilized in topical delivery formulations. The strong affinity of positively charged chitosan nanoparticles toward negatively charged biological membranes can be exploited to achieve site-specific targeting. Objective: To investigate the use of chitosan nanoparticles (CSNPs) as carrier units to enhance the topical delivery of β-arbutin. Method: CSNPs containing β-arbutin were prepared using an ionic cross-linking method, and entrapment efficiency and loading capacity were evaluated at numerous β-arbutin concentrations. Further characterization involved using FTIR, XRD, TEM, and TGA, and in vitro permeation studies were conducted using in vitro Franz diffusion cells. Results: β-arbutin chitosan nanoparticles were successfully formulated with a size range of 211–289 d.nm, a polydispersity index between 0.2–0.3, and zeta potential in the range 46.9–64.0 mV. The optimum encapsulation efficiency (EE) and loading capacity (LC) of β-arbutin were 68% and 73%, respectively. TEM revealed the nanoparticles to be spherical in shape. FTIR spectra revealed characteristic chitosan-related peaks appearing at 3438.3 cm−1 (-OH stretching) and 3320 cm−1 (-CH stretching), together with 1598.01 cm−1 (-NH2) specific to β-arbutin nanoparticles. XRD analysis revealed an increase in crystallinity and TGA analyses identified increasing thermal stability with increasing β-arbutin concentration. In vitro studies indicated higher permeation and improved penetration of β-arbutin loaded in CSNPs compared to its free form. Conclusion: CSNPs present considerable promise as effective carriers for improved topical delivery of β-arbutin.

“Spanlastic nanovesicles for enhanced ocular delivery of vanillic acid: design, in vitro characterization, and in vivo anti-inflammatory evaluation”

Spanlastics are novel surfactant-based, elastic vesicular nanocarriers composed of spans and edge activators. The present work aims to exploit their special penetration enhancing properties to enhance the ophthalmic delivery of the versatile nutraceutical vanillic acid (VA), for treatment of ocular inflammation. VA-loaded spanlastics were formulated by ethanol injection method using Tween 80, sodium deoxy cholate or Tween 60 as edge activators (EA) at various Span 60: EA mass ratios. Vesicles were characterized for their particle size (PS), polydispersity index (PDI), zeta potential, entrapment efficiency (EE%), surface morphology, in vitro release profile, thermal properties and long-term stability, in addition to in vivo anti-inflammatory efficacy of the selected formula in an endotoxin-induced uveitis model. Selected formulation composed of Span 60: Tween 80 at a mass ratio of 70:30 displayed smallest PS of 299.8±9.97nm, PDI of 0.386±0.047, an acceptable EE%, as well as good physical stability for 3months. According to clinical scoring, inflammatory mediators levels and histopathological examination, VA-loaded spanlastic formulation resulted in significant alleviation of inflammation compared to drug suspension (p<0.05). Formulation of VA into spanlastic nanoformulation is a promising approach to improve its ocular permeability, absorption and anti-inflammatory activity providing a safer alternative to current regimens.

Comparison Between Franz Diffusion Cell and a novel Micro-physiological System for In Vitro Penetration Assay Using Different Skin Models.

In vitro diffusive models are an important tool to screen the penetration ability of active ingredients in various formulations. A reliable assessment of skin penetration enhancing properties, mechanism of action of carrier systems, and an estimation of a bioavailability are essential for transdermal delivery. Given the importance of testing the penetration kinetics of different compounds across the skin barrier, several in vitro models have been developedThe aim of this study was to compare the Franz Diffusion Cell (FDC) with a novel fluid-dynamic platform (MIVO) by evaluating penetration ability of caffeine, a widely used reference substance, and LIP1, a testing molecule having the same molecular weight but a different lipophilicity in the two diffusion chamber systems. A 0.7% caffeine or LIP1 formulation in either water or propylene glycol (PG) containing oleic acid (OA) was topically applied on the Strat-M® membrane or pig ear skin, according to the infinite-dose experimental condition (780 ul/cm2). The profile of the penetration kinetics was determined by quantify the amount of molecule absorbed at different time-points (1, 2, 4, 6, 8 hours), by means of HPLC analysis. Both diffusive systems show a similar trend for caffeine and LIP1 penetration kinetics. The Strat-M® skin model shows a lower barrier function than the pig skin biopsies, whereby the PGOA vehicle exhibits a higher penetration, enhancing the effect for both diffusive chambers and skin surrogates. Most interestingly, MIVO diffusive system better predicts the lipophilic molecules (i.e. LIP1) permeation through highly physiological fluid flows resembled below the skin models.

Lamellar Lyotropic Liquid Crystal Phases as a Carrier for Skin Delivery of &lt;i&gt;Morus alba&lt;/i&gt; Stem Extract

Morus alba stem extract possesses several biological activities. However, skin delivery of the extract is limited by the stratum corneum. In this study, lamellar lyotropic liquid crystal (LLC) was investigated for the potential application in the skin delivery of M. alba stem extract. The four formulations were developed and incorporated with M. alba stem extract at 3% w/w. These formulations were stored at room temperature in light-protected containers for 3 months. The optical pattern under polarized light microscope, viscosity and remaining of the extract were determined. The skin penetration enhancing property of the formulations was investigated using excised porcine ear skin model. The results showed that all formulations remained stable after 3-month storage. The two formulations exhibiting good penetration enhancing properties were F3 consisting of PEG-7 glyceryl cocoate/n-Dodecane/Water/extract (55.29/19.40/22.31/3.00 %w/w) and F4 consisting of mixed Surfactant/n-Dodecane/Water/extract (48.50/4.85/43.65/3.00 %w/w). The mixed surfactant composed of PEG-7 glyceryl cocoate/PEG-40 hydrogenated castor oil/Glyceryl oleate (40/33.24/26.76 %w/w). It can be concluded that the lamellar LLC formulations developed in this study can be used as a carrier for delivering of M. alba stem extract. The components of the formulations which play important roles are the oil and the surfactant.

Development of oral aprepitant-loaded chitosan–polyethylene glycol-coated cyclodextrin nanocapsules: formulation, characterization, and pharmacokinetic evaluation

Aprepitant (APRT), a selective neurokinin 1 antagonist, is clinically used in the prevention of acute and delayed chemotherapy-induced nausea and vomiting. The low solubility of APRT, which limits its oral bioavailability, is overcome by nanonization. This study aimed to design and evaluate novel in vitro and in vivo chitosan (CS)–polyethylene glycol (PEG)-coated cyclodextrin (CD) nanoparticles and nanocapsules to enhance the solubility and oral bioavailability of APRT. A novel amphiphilic CD derivative with alkyl chains of 9 carbons (ACD-C9) was synthesized to form nanoparticles and nanocapsules by using nanoprecipitation. The nanocarriers were coated with the CS–PEG conjugate to increase their biological interaction with cell membranes via the positive charge and penetration-enhancer properties of CS. The nanosystems were evaluated for particle size, surface charge, drug loading, imaging, release, cell culture, and oral bioavailability in an animal model. The CS–PEG-coated nanosystems had particle size of 400–550 nm, a narrow polydispersity index, positive zeta potential, and favorable drug loading (55 and 93% for nanoparticles and nanocapsules, respectively). Sustained release was observed within 24 h. Blank nanoparticles and nanocapsules were non-cytotoxic against the L929 cell line. The intestinal permeability of the nanocarriers was 2–threefold (2-3 fold) higher than that of the drug solution, and the nanocapsules afforded the highest APRT permeability through Caco-2 cells. Oral bioavailability studies in rats revealed comparable degree of drug absorption between nanocapsules and commercial APRT products. Oral ACD-C9 nanocapsules have the potential for the treatment of chemotherapy-induced nausea and vomiting.

The Effect of Acid Modification of Porcine Mucin on Its Drug Release and Skin Permeation Properties in Insulin Transdermal Films

Background: The transdermal delivery of insulin involving the use of polymers has been extensively reported. More recently, the use of mucoadhesive or bioadhesive polymers as an insulin base in its formulation is gaining attention possibly due to the penetration enhancing properties of the polymers.&#x0D; Objectives: This study aimed at determining the effect of acid-modified porcine mucin powder on the release and permeation of insulin in transdermal films.&#x0D; Methods: Various batches of insulin films were prepared by solvent casting method using polysorbate 80 as an emulsifying agent and acid-treated and untreated mucin powders as a base. The films were evaluated for their physical properties, folding endurance, moisture content and uptake, drug content, bioadhesion, in vitro release, ex vivo permeation, and in vivo glucose-lowering activity.&#x0D; Results: The prepared insulin films had a weight range of 0.21-0.27 g, folding endurance of 101-103, moisture content and uptake of 13.73%-18.57% and 11.70%-22.30%, respectively, and drug content of 96%-101%. The bioadhesion of the films prepared with acid-treated mucin was within the range of 0.088-0.186 Nm-1 as against 0.055 Nm-1 of the films prepared with untreated mucin. The in vitro release profiles showed a release of 95% insulin from films prepared with untreated mucin within 2 h while the films made with acid-treated mucin gave a release of about 60%-73% over the same period, indicating a slower release. Animals that received acid-treated mucin-base insulin films showed delayed but sustained blood-glucose-lowering up to 70% and for films prepared with untreated mucin 55% within 12 h. &#x0D; Conclusion: Insulin transdermal films prepared with acid-modified mucin powder gave superior bioadhesive strength values. They also showed improved drug permeation enhancing ability and achieving up to 70% blood glucose lowering in diabetic rats.

Sulfoxide-functionalized nanogels inspired by the skin penetration properties of DMSO.

Among polymeric nanocarriers, nanogels are especially promising non-irritating delivery vehicles to increase dermal bioavailability of therapeutics. However, accurately tailoring defined interactions with the amphiphilic skin barrier is still challenging. To address this limited specificity, we herein present a new strategy to combine biocompatible nanogels with the outstanding skin interaction properties of sulfoxide moieties. These chemical motifs are known from dimethyl sulfoxide (DMSO), a potent chemical penetration enhancer, which can often cause undesired skin damage upon long-term usage. By covalently functionalizing the nanogels' polymer network with such methyl sulfoxide side groups, tailor-made dermal delivery vehicles are developed to circumvent the skin disrupting properties of the small molecules. Key to an effective nanogel-skin interaction is assumed to be the specific nanogel amphiphilicity. This is examined by comparing the delivery efficiency of sulfoxide-based nanogels (NG-SOMe) with their corresponding thioether (NG-SMe) and sulfone-functionalized (NG-SO2Me) analogues. We demonstrate that the amphiphilic sulfoxide-based NG-SOMe nanogels are superior in their interaction with the likewise amphipathic stratum corneum (SC) showing an increased topical delivery efficacy of Nile red (NR) to the viable epidermis (VE) of excised human skin. In addition, toxicological studies on keratinocytes and fibroblasts show good biocompatibility while no perturbation of the complex protein and lipid distribution is observed via stimulated Raman microscopy. Thus, our NG-SOMe nanogels show high potential to effectively emulate the skin penetration enhancing properties of DMSO without its negative side effects.

Phospholipid Vesicles for Dermal/Transdermal and Nasal Administration of Active Molecules: The Effect of Surfactants and Alcohols on the Fluidity of Their Lipid Bilayers and Penetration Enhancement Properties.

This is a comprehensive review on the use of phospholipid nanovesicles for dermal/transdermal and nasal drug administration. Phospholipid-based vesicular carriers have been widely investigated for enhanced drug delivery via dermal/transdermal routes. Classic phospholipid vesicles, liposomes, do not penetrate the deep layers of the skin, but remain confined to the upper stratum corneum. The literature describes several approaches with the aim of altering the properties of these vesicles to improve their penetration properties. Transfersomes and ethosomes are the most investigated penetration-enhancing phospholipid nanovesicles, obtained by the incorporation of surfactant edge activators and high concentrations of ethanol, respectively. These two types of vesicles differ in terms of their structure, characteristics, mechanism of action and mode of application on the skin. Edge activators contribute to the deformability and elasticity of transfersomes, enabling them to penetrate through pores much smaller than their own size. The ethanol high concentration in ethosomes generates a soft vesicle by fluidizing the phospholipid bilayers, allowing the vesicle to penetrate deeper into the skin. Glycerosomes and transethosomes, phospholipid vesicles containing glycerol or a mixture of ethanol and edge activators, respectively, are also covered. This review discusses the effects of edge activators, ethanol and glycerol on the phospholipid vesicle, emphasizing the differences between a soft and an elastic nanovesicle, and presents their different preparation methods. To date, these differences have not been comparatively discussed. The review presents a large number of active molecules incorporated in these carriers and investigated in vitro, in vivo or in clinical human tests.

Chitosan-based particulate systems for drug and vaccine delivery in the treatment and prevention of neglected tropical diseases.

Neglected tropical diseases (NTDs) are a diverse group of infections which are difficult to prevent or control, affecting impoverished communities that are unique to tropical or subtropical regions. In spite of the low number of drugs that are currently used for the treatment of these diseases, progress on new drug discovery and development for NTDs is still very limited. Therefore, strategies on the development of new delivery systems for current drugs have been the main focus of formulators to provide improved efficacy and safety. In recent years, particulate delivery systems at micro- and nanosize, including polymeric micro- and nanoparticles, liposomes, solid lipid nanoparticles, metallic nanoparticles, and nanoemulsions, have been widely investigated in the treatment and control of NTDs. Among these polymers used for the preparation of such systems is chitosan, which is a marine biopolymer obtained from the shells of crustaceans. Chitosan has been investigated as a delivery system due to the versatility of its physicochemical properties as well as bioadhesive and penetration-enhancing properties. Furthermore, chitosan can be also used to improve treatment due to its bioactive properties such as antimicrobial, tissue regeneration, etc. In this review, after giving a brief introduction to neglected diseases and particulate systems developed for the treatment and control of NTDs, the chitosan-based systems will be described in more detail and the recent studies on these systems will be reviewed. Graphical abstract.

Chitosan Nanoparticles for Therapy and Theranostics of Hepatocellular Carcinoma (HCC) and Liver-Targeting.

Chitosan nanoparticles are well-known delivery systems widely used as polymeric carriers in the field of nanomedicine. Chitosan is a carbohydrate of natural origin: it is a biodegradable, biocompatible, mucoadhesive, polycationic polymer and it is endowed with penetration enhancer properties. Furthermore, it can be easily derivatized. Hepatocellular carcinoma (HCC) represents a remarkable health problem because current therapies, that include surgery, liver transplantation, trans-arterial embolization, chemoembolization and chemotherapy, present significant limitations due to the high risk of recurrence, to a lack of drug selectivity and to other serious side effects. Therefore, there is the need for new therapeutic strategies and for improving the liver-targeting to HCC. Nanomedicine consists in the use of nanoscale carriers as delivery systems to target and deliver drugs and/or diagnostic agents to specific organs or tissues. Chitosan and its derivatives can be successfully used in the preparation of nanoparticles that, for their peculiar surface-properties, can specifically interact with liver tumor, by passive and active targeting. This review concerns the use of chitosan nanoparticles for the therapy and theranostics of HCC and liver-targeting.

In vitro transdermal permeation of main compositions in Baimai Ointment

To establish a determination method for the contents of ammonium glycyrrhetate,nardosinone,and curcumin in transdermal receptor liquid of Baimai Ointment,and investigate the percutaneous permeability of Baimai Ointment and the effects of two kinds of penetration enhancers on percutaneous absorption of three components. The contents of ammonium glycyrrhetate,nardosinone,and curcumin in transdermal receptor liquid were determined by high pressure liquid chromatography( HPLC). The vertical modified Franz diffusion cell was used to perform a transdermal experiment in vitro with the abdominal skin of mice( treated and untreated). The transdermal receptor liquid was preferably used to investigate the transdermal absorption rule of the Baimai Ointment and the effect of the penetration enhancer. The results showed that the comprehensive solubility of PEG-ET-NS( 3 ∶3 ∶4) was best among three types of receptor liquid PG-ET-NS( 3 ∶3 ∶4),PEG-ET-NS( 3 ∶3 ∶4),ET-NS( 3 ∶7). PEG-ET-NS was used as the receptor liquid for in vitro transdermal experiments. The cumulative permeation area of ammonium glycyrrhetate,nardosinone and curcumin within 24 h was 5. 73,18. 99,0. 38 μg·cm~(-2)respectively. Taking QEFand ER as comprehensive evaluation indicators of permeation performance,the comprehensive penetration-promoting performance of ammonium glycyrrhizinate: 3% PEG 400-ethanol-normal saline ≈ 1. 19 times( 3%azone) = 1. 94 times( blank); comprehensive penetration-promoting performance of nardosinone: 3% PEG 400-ethanol-normal saline≈1. 28 times( 3% azone) = 1. 37 times( blank); the comprehensive penetration performance of curcumin: 3% PEG 400-ethanol-normal saline≈1. 77 times( 3% azone) ≈3. 42 times( blank). The comprehensive penetration enhancement properties of the two penetration enhancers were as follows: 3% PEG 400-ethanol-normal saline>3%azone>blank. The transdermal absorption curve of ammonium glycyrrhetate,nardosinone and curcumin in Baimai Ointment were consistent with the zero-order equation,indicating that the transdermal absorption process was irrelevant to the concentration of three components,and its was a diffusion process. This experiment provides reference for the study of ointment transdermal preparations.