Development of alginate-reinforced chitosan nanoparticles utilizing W/O nanoemulsification/internal crosslinking technique for transdermal delivery of rabeprazole

Chitosan Alginate Nanoparticles of Protein Hydrolysate from Acheta domesticus with Enhanced Stability for Skin Delivery

This study aimed to develop chitosan alginate nanoparticles (CANPs) for enhanced stability for dermal delivery of protein hydrolysate from Acheta domesticus (PH). CANPs, developed using ionotropic pre-gelation followed by the polyelectrolyte complex technique, were characterized for particle size, polydispersity index (PDI), and zeta potential. After the incorporation of PH into CANPs, a comprehensive assessment included encapsulation efficiency, loading capacity, morphology, chemical analyses, physical and chemical stability, irritation potential, release profile, skin permeation, and skin retention. The most optimal CANPs, comprising 0.6 mg/mL sodium alginate, 1.8 mg/mL calcium chloride, and 0.1 mg/mL chitosan, exhibited the smallest particle size (309 ± 0 nm), the narrowest PDI (0.39 ± 0.01), and pronounced negative zeta potential (-26.0 ± 0.9 mV), along with an encapsulation efficiency of 56 ± 2%, loading capacity of 2.4 ± 0.1%, release of 40 ± 2% after 48 h, and the highest skin retention of 12 ± 1%. The CANPs induced no irritation and effectively enhanced the stability of PH from 44 ± 5% of PH remaining in a solution to 74 ± 4% after three-month storage. Therefore, the findings revealed the considerable potential of CANPs in improving PH stability and skin delivery, with promising applications in cosmetics and related fields.

Formulation of Folate Receptor-Targeted Silibinin-Loaded Inhalable Chitosan Nanoparticles by the QbD Approach for Lung Cancer Targeted Delivery

Aim: Targeted delivery of chemotherapeutics by functionalized nanoparticles exhibits a wonderful prospect for cancer treatment. The main objective of this research was to develop folate receptor-targeted silibinin (SB)-loaded inhalable polymeric nanoparticles (FA-CS-SB-NPs) for the treatment of lung cancer. Method: The qbD approach was implemented to prepare SB-loaded nanoparticles. Folic acid was conjugated by electrostatic conjugation in an optimized batch. The therapeutic potentials of formulations were determined using a lung cancer cell-bearing rat model. Result: Optimized formulation exhibited a spherical surface with a mean particle size of 275 ± 1.20 nm, a PDI of 0.234 ± 0.07, a ζ-potential of 32.50 ± 0.21, an entrapment efficiency of 75.52 ± 0.87%, and a CDR of 63.25 ± 1.21% at 48 h. Aerodynamic behaviors such as the mass median aerodynamic diameter (MMAD) and geometric size distribution (GSD) were found to be 2.75 ± 1.02 and 3.15 ± 0.88 μm, respectively. After 24 h of incubation with FA-CS-SB-NPs, the IC50 value was found to be 24.5 g/mL. FA-SB-CS-NPs maintained a significantly higher deposition of SB in lung tissues. Conclusions: Thus, the noninvasive nature and target specificity of FA-CS-SB-NPs pave the way for pulmonary delivery for treating lung cancer.

Development and evaluation of quercetin enriched bentonite-reinforced starch-gelatin based bioplastic with antimicrobial property

Nowadays novel bio-based materials have been widely employed in food and pharmaceutical industry because of their wide acceptability by the consumers rather than the synthetic materials nevertheless, they possess poor mechanical properties. Reinforcement of biopolymers with intercalation of mineral clays can improve their physicochemical properties; so that such biocomposites possess superior barrier and mechanical properties as well as stability and drug loading efficacy. Thus, this research aimed at formulating quercetin loaded bentonite-reinforced starch-gelatin based novel bioplastic with diverse applicability. The methodology of the study included Box Behnken optimization as well as physical, structural, mechanical and antimicrobial properties evaluation of the proposed reinforced bioplastics. Amount of starch, bentonite and glycerin were the independent variables while the tensile strength, swelling index and elongation percentage were studied as dependent variables. The optimized bioplastic film showed excellent physicochemical and morphological characteristics and also for efficient percentage drug content. The antimicrobial activity showed the highest activity against Escherichia coli followed by Pseudomonas aeruginosa and Staphylococcus aureus. Scanning electron microscopy (SEM) revealed the non-homogenous nature of the film. Generally, the results revealed that quercetin loaded bentonite-reinforced starch-gelatin based could be used as ecological friendly active food packaging as well as pharmaceutical application with significant antimicrobial properties.

In vitro and in vivo characterization of Miconazole Nitrate loaded transethosomes for the treatment of Cutaneous Candidiasis

This study aimed to fabricate Miconazole Nitrate transethosomes (MCZN TESs) embedded in chitosan-based gel for the topical treatment of Cutaneous Candidiasis. A thin film hydration method was employed to formulate MCZN TESs. The prepared MCZN TESs were optimized and analyzed for their physicochemical properties including particle size (PS), polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (%EE), Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), deformability, and Transmission electron microscopy (TEM). In vitro release, skin permeation and deposition, skin irritation, antifungal assay, and in vivo efficacy against infected rats were evaluated. The optimized MCZN TESs showed PS of 224.8 ± 5.1 nm, ZP 21.1 ± 1.10 mV, PDI 0.207 ± 0.009, and % EE 94.12 ± 0.101 % with sustained drug release profile. Moreover, MCZN TESs Gel exhibited desirable pH, spreadability, and viscosity. Notably, the penetration and deposition capabilities of MCZN TESs Gel showed a 4-fold enhancement compared to MCZN TESs. Importantly, in vitro antifungal assay elaborated MCZN TESs Gel anti-fungal activity was 2.38-fold more compared to MCZN Gel. In vivo, studies showed a 1.5 times reduction in the duration of treatment MCZN TESs Gel treated animal group. Therefore, studies demonstrated that MCZN TESs could be a suitable drug delivery system with higher penetration and good antifungal potential.

Characterization and Release Mechanisms of Aerogel-Encapsulated Biocide Crystals for Low-Loading and High-Utilization Antifouling Coatings

Silica aerogel-encapsulated biocide crystals can potentially enhance the protection efficiency of antifouling coatings, thereby lowering the impact on nontarget aquatic life. In the present study, copper pyrithione (CuPT) crystals are encapsulated by silica aerogel to obtain loadings of 50-80 wt % CuPT. For optimal design of the heterogeneous particles and mapping of the underlying biocide release mechanisms, the aerogel-encapsulated biocide crystals are characterized by scanning (transmission) electron microscopy, energy-dispersive X-ray spectroscopy, thermal gravimetric analysis, mercury intrusion porosity, Brunauer-Emmett-Teller analysis, and light scattering. The microscopic examination demonstrates that the elongated CuPT crystals are encapsulated by a thin highly porous silica layer. When varying the CuPT loading of the aerogels, it is possible to tune the particle size, pore volume, and specific surface area of the aerogels. Furthermore, this study suggests that the hydrophilic aerogel-encapsulated CuPT, when used in antifouling coatings, attracts seawater and contributes to an efficient controlled release of active CuPT.

Alginate as a Promising Biopolymer in Drug Delivery and Wound Healing: A Review of the State-of-the-Art

Biopolymeric nanoparticulate systems hold favorable carrier properties for active delivery. The enhancement in the research interest in alginate formulations in biomedical and pharmaceutical research, owing to its biodegradable, biocompatible, and bioadhesive characteristics, reiterates its future use as an efficient drug delivery matrix. Alginates, obtained from natural sources, are the colloidal polysaccharide group, which are water-soluble, non-toxic, and non-irritant. These are linear copolymeric blocks of α-(1→4)-linked l-guluronic acid (G) and β-(1→4)-linked d-mannuronic acid (M) residues. Owing to the monosaccharide sequencing and the enzymatically governed reactions, alginates are well-known as an essential bio-polymer group for multifarious biomedical implementations. Additionally, alginate’s bio-adhesive property makes it significant in the pharmaceutical industry. Alginate has shown immense potential in wound healing and drug delivery applications to date because its gel-forming ability maintains the structural resemblance to the extracellular matrices in tissues and can be altered to perform numerous crucial functions. The initial section of this review will deliver a perception of the extraction source and alginate’s remarkable properties. Furthermore, we have aspired to discuss the current literature on alginate utilization as a biopolymeric carrier for drug delivery through numerous administration routes. Finally, the latest investigations on alginate composite utilization in wound healing are addressed.

In vitro cytocompatibility assessment and antibacterial effects of quercetin encapsulated alginate/chitosan nanoparticle

The present work aims at evaluating the in vitro biocompatibility, antibacterial activity and antioxidant capacity of the fabricated and optimized Alginate/Chitosan nanoparticles (ALG/CSNPs) and quercetin loaded Alginate/Chitosan nanoparticles (Q-ALG/CSNPs) with an improved biological efficacy on the hydrophobic flavonoid.The physicochemical properties were determined by TEM and FTIR analysis. The nanoparticles evaluated for the encapsulation of quercetin exerted % encapsulation efficiency (EE) that varied between 76 and 82.4 % and loading capacity (LC) from 31 to 46.5 %. Potential cytotoxicity of the ALG/CSNPs and Q-ALG/CSNPs upon L929 fibroblast cell line was evaluated by MTT reduction Assay and expressed as % cell viability. The in vitro antibacterial property was studied by well diffusion method against gram-positive bacteria Staphylococcus aureus (ATCC 25925) and gram-negative bacteria Escherichia coli (ATCC 25923). The inhibitory efficacy by scavenging free radical intermediates was evaluated by 1,1, diphenyl 2-picrylhydrazyl (DPPH) assay. The results of in vitro cytotoxicity showed biocompatibility towards L929 cells. Quercetin loaded Alginate/Chitosan nanoparticles inhibited the growth of microorganisms than pure quercetin. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging results have shown a high level of antioxidant property for encapsulated Quercetin in Alginate/Chitosan nanoparticles compared to free Quercetin. The findings of our study suggest that the developed ALG/CSNPs and Q-ALG/CSNPs possess the prerequisites and be proposed as a suitable system for delivering quercetin with enhanced therapeutic effectuality.

Nanoemulsion-based dosage forms for the transdermal drug delivery applications: A review of recent advances

INTRODUCTION

Nanoemulsion-based drug delivery approaches have witnessed massive acceptance over the years and acquired a significant foothold owing to their tremendous benefits over the others. It has widely been used for transdermal delivery of hydrophobic and hydrophilic drugs with solubility, lipophilicity, and bioavailability issues.

AREAS COVERED

The review highlights the recent advancements and applications of transdermal nanoemulsions. Their utilities and characteristics, clinical pertinence showcasing intellectual properties and advancements, potential in treating disorders accompanying liquid, semisolid, and solid dosage forms, the ability to modulate a drug's physicochemical properties, and regulatory status are thoroughly summarized.

EXPERT OPINION

Despite tremendous therapeutic utilities and extensive investigations, this field of transdermal nanoemulsion-based technologies yet tackles several challenges such as optimum use of surfactant mixtures, economic burden due to high energy consumption during production, lack of concrete regulatory requirement, etc. Provided with the concrete guidelines on the safe use of surfactants, stability, use of scalable and economical methods, and the use of NE as a transdermal system would solve the purpose best as nanoemulsion shows remarkable improvement in drug release profiles and bioavailability of many drugs. Nevertheless, a better understanding of nanoemulsion technology holds a promising outlook and would land more opportunities and better delivery outcomes.

Transdermal Film Loaded with Avanafil Ultra-deformable Nanovesicles to Enhance its Percutaneous Absorption and Bioavailability

The in vitro dissolution of Avanafil (AVA) is the rate-limiting step for its bioavailability. Also, it undergoes the first-pass metabolism, and its absorption is altered significantly in the presence of food. So, our study aimed to overcome the previous hurdles and improve the AVA bioavailability by its incorporation in the ultra-deformable nanovesicles, transfersomes (TRF), then loading these nanovesicles in transdermal films. The AVA-loaded TRF formulation was optimized using Draper-Lin small composite design (D-LSCD). The optimized AVA-loaded TRF was evaluated for quality attributes and assessed for skin permeation using a fluorescence laser microscope and for pharmacokinetic parameters after topical application on the rats. The optimized AVA-loaded TRF showed a vesicle size of 97.75 nm, a zeta potential of -28.83 mV, and entrapment efficiency of 95.14% with good deformability and release profile. The intense discoloration in the deep skin layers of the rats indicated the permeation efficiency of AVA-loaded TRF films. The pharmacokinetic parameters specified the augmented absorption extent with C_max of 254.66 ± 8.02 ng/mlversus 70.33 ± 3.05 ng/ml which reflected on the AUC_0-inf that has a value of 2050.45 ± 159.14 ng/ml h versus 497.34 ± 102.61 ng/ml h for the optimized AVA-loaded TRF film and raw AVA-loaded film, respectively. These promising results wide open the field for broader clinical application of this alternative delivery pathway for superior bioavailability, efficacy, and patient compliance and satisfaction.

Isotretinoin-Delonix polymeric nanoparticles: Potentials for skin follicular targeting in acne treatment

In acne management, oral isotretinoin (IST) is associated with various untoward systemic effects, while its topical formulation has irritation side effects. Delonix (DLX) is a natural galactomannan derived from Delonix regia seed that can fabricate nanoparticles for topical skin delivery. This study aims to develop IST-DLX nanoparticles and assess their prospects for acne treatment. Fluorescent-DLX nanoparticles (made with a lipophilic BODIPY dye) or IST-DLX nanoparticles were prepared and characterized. BODIPY-DLX nanoparticles' skin distribution and IST-DLX nanoparticles' in-vitro targeting were assessed in pig ear skin, inflammatory modulation was assessed in AMJ-2 macrophage cells, while skin penetration and irritation were assessed in Wistar rats. IST-DLX nanoparticles had ≈230 nm, negative zeta potential, and ≈30% encapsulation efficiency. Confocal showed BODIPY in DLX nanoparticles accumulated in hair follicles as compared to BODIPY solution. IST-DLX nanoparticles released ≈37% IST over 48 h and increased IST 3-fold in hair follicles compared to IST solution. IST-DLX nanoparticles suppressed IL-6 expression in cells and reduced photo-irritation in Wistar rats compared to IST solution. In conclusion, IST-DLX nanoparticles may target and deliver adequate IST to skin layers associated with acne, avoid systemic penetration, modulate inflammatory pathogenic acne stage and prevent IST topical photo-irritation.

Mapping hair follicle-targeted delivery by particle systems: What has science accomplished so far?

The importance of the hair follicle in the process of cutaneous drug penetration has been established since this skin appendage was recognized as an entry point for topically applied substances. A comprehensive review on the hair follicle as a target per se is here provided, exploring the current knowledge on both targeted regions and delivery systems that take advantage of this permeation route. The follicular penetration is a complex process, whose effectiveness and efficiency strongly depends on a diversity of different factors including follicular density and size, activity status of hair follicles and physicochemical properties of the topically applied substances. Nanocarriers represent a heterogeneous assembly of molecules organized into particles and they have revolutionized drug delivery in several areas of medicine, pharmacology and cosmetics. As they possess an inherent ability to use the follicular route, they are reviewed here having in perspective the hair follicle zones that they are able to reach as reported. In this way, a follicular road map for the different delivery systems was compiled to assist as a guiding tool for those that have interest in the development and/or application of such delivery systems for hair and skin treatment or care.

The technology of transdermal delivery nanosystems: from design and development to preclinical studies

Transdermal administration has gained much attention due to the remarkable advantages such as patient compliance, drug escape from first-pass elimination, favorable pharmacokinetic profile and prolonged release properties. However, the major limitation of these systems is the limited skin penetration of the stratum corneum, the skin's most important barrier, which protects the body from the insertion of substances from the environment. Transdermal drug delivery systems are aiming to the disruption of the stratum corneum in order for the active pharmaceutical ingredients to enter successfully the circulation. Therefore, nanoparticles are holding a great promise because they can act as effective penetration enhancers due to their small size and other physicochemical properties that will be analyzed thoroughly in this report. Apart from the investigation of the physicochemical parameters, a comparison between the different types of nanoparticles will be performed. The complexity of skin anatomy and the unclear mechanisms of penetration should be taken into consideration to reach some realistic conclusions regarding the way that the described parameters affect the skin permeability. To the best of the authors knowledge, this is among the few reports on the literature describing the technology of transdermal delivery systems and how this technology affects the biological activity.

Development of Pomegranate Extract-Loaded Solid Lipid Nanoparticles: Quality by Design Approach to Screen the Variables Affecting the Quality Attributes and Characterization

The aim of this work was to study the influence of process variables on the quality attributes of pomegranate extract loaded solid lipid nanoparticles (PE-SLNs) using Plackett-Burman design. PE-SLN formulations were prepared by hot homogenization followed by ultra-sonication technique and evaluated based on the dependent variables that were analyzed utilizing Statgraphics Centurion XV software. The lipid and surfactant (type and concentration), co-surfactant concentration, sonication time, and amplitude were selected as the independent variables (X ₁-X ₇). The dependent parameters were particle size, polydispersity index, zeta potential, entrapment efficiency, and cumulative drug release (Y ₁-Y ₅). Response surface plots, Pareto charts, and mathematical equations were generated to study the influence of independent variables on the dependent quality parameters. Out of seven variables, X ₁, X ₂, and X ₆ have the main significant (p value < 0.05) effect on the entrapment efficiency, the cumulative drug release, the polydispersity index, respectively, while particle size was mainly affected by X ₃, X ₆ and zeta potential by X ₁, X ₃, and X ₄. Consequently, this screening study revealed that stearic acid as lipid, Tween 80 as surfactant, as well as sonication with short time and high amplitude can be selected for the development of PE-SLN formulation with minimum particle size, maximum zeta potential, highest entrapment, and sustained drug release behavior. Meanwhile, concentrations of lipid, surfactant, and co-surfactant are planned to be scaled up for further optimization study. In conclusion, the Plackett-Burman design verified its influence and significance in determining and understanding both process and formulation variables affecting the quality of PE-SLNs.

Duloxetine hydrochloride loaded film forming dermal gel enriched with methylcobalamin and geranium oil attenuates paclitaxel-induced peripheral neuropathy in rats

Objective

In attempt to conquer the major concerns of oral duloxetine hydrochloride (like low bioavailability, intolerable side-effects and no regeneration of demyelinated nerve fibres) for the management of chemotherapy-induced peripheral neuropathy (CIPN), an alternative delivery of duloxetine hydrochloride was aimed for in-vivo optimization.

Methods

A film forming dermal gel consisting of duloxetine hydrochloride was formulated and enriched with methylcobalamin and geranium oil. The formulated gel successfully qualified the various pharmaceutical characteristics of gel. Administration of paclitaxel (8 mg/kg/i.p. in four divided doses) for 4 alternate days induced the symptoms of peripheral neuropathy in rats. On 14th day, the responses to noxious stimulus (mechanical hyperalgesia, cold allodynia, and heat hyperalgesia) were increased and reached to its maximum. Thereafter, drug treatment with formulated dermal gel and oral duloxetine hydrochloride (30 mg/kg, once daily) was initiated for 2 weeks in different group of animals. On the 28th day animals were sacrificed to isolate sciatic nerve, to assess biochemical changes (TBARS, reduced GSH, total protein, TNF-α, IL-6) and for histopathological examinations of nerve sections using Hematoxylin-Eosin and Toludine blue staining methods.

Results

Application of formulated dermal gel to paclitaxel-treated rats significantly improved paw-withdrawal latency responses during noxious stimulus testing, reduced the levels of TBARS, TNF-α, IL-6 and elevated the levels of reduced GSH as compared to paclitaxel treated rats. Histographs also indicated marked regeneration of the damaged nerve fibers. Topical delivery of duloxetine hydrochloride produced similar results in disparity to oral route. However, no significant disparity in responses was obtained with twice application of formulated dermal gel when compared to once daily application.

Conclusion

Tremendous recovery from nociception, oxidation and inflammation in addition to nerve degeneration was achieved through dermal application of duloxetine hydrochloride in peripheral neuropathy.

Enhancement of Simvastatin ex vivo Permeation from Mucoadhesive Buccal Films Loaded with Dual Drug Release Carriers

BACKGROUND

Simvastatin (SMV), a hypocholesterolemic agent, suffers from very low bioavailability due to its poor aqueous solubility and extensive first-pass metabolism.

METHODS

Two SMV carrier systems, namely, polymeric drug inclusion complex (IC) and mixed micelles (MM) nanoparticles, were developed and loaded into mucoadhesive buccal films to enhance SMV bioavailability. The two carrier systems were characterized and their permeation across human oral epithelial cells (OEC) was studied. The effect of IC to MM ratio (X1) and the mucoadhesive polymer concentration (X2) on the cumulative percent of drug released, elongation percent and the mucoadhesive strength, from the prepared mucoadhesive films, were optimized. Ex vivo permeation across bovine mucosal tissue was investigated. The permeation parameters for the in vitro and ex vivo release data were calculated.

RESULTS

Complexation of SMV with hydroxypropyl beta-cyclodextrin (HP β-CD) was superior to all other polymers as revealed by the equilibrium saturation solubility, stability constant, complexation efficiency and thermodynamic potential. SMV-HP β-CD IC was utilized to develop a saturated polymeric drug solution. Both carrier systems showed enhanced permeation across OEC when compared to pure drug. X1 and X2 were significantly affecting the characteristics of the prepared films. The optimized mucoadhesive buccal film formulation loaded with SMV IC and drug MM nanoparticles demonstrated superior ex vivo permeation when compared to the corresponding pure drug buccal film, and the calculated permeation parameters confirmed this finding.

CONCLUSION

Mucoadhesive buccal films containing SMV IC and drug MM can be used to improve drug bioavailability; however, additional pharmacokinetic and pharmacodynamic studies are required.

Two-Step Optimization to Develop a Transdermal Film Loaded With Dapoxetine Nanoparticles: A Promising Technique to Improve Drug Skin Permeation

Dapoxetine (DPX) is an orally administered drug for the treatment of premature ejaculation (PE). One of the challenges of administering DPX orally as a tablet is its poor bioavailability (ie, 42%) due to extensive first-pass metabolism. Thus, it is vital to develop a new formulation and mode of delivery to achieve the unmet needs of PE treatment. In this study, an optimized DPX polymeric nanoparticle (PNP) was developed and subsequently loaded into a transdermal film. The Box–Behnken design was utilized to optimize 3 formulation factors affecting the particle size and entrapment efficiency (EE) of chitosan (CS)-alginate (ALG) PNPs. A 3-level factorial design was used to study the effect of 2 variables affecting DPX cumulative percent released and percent elongation from transdermal films loaded with DPX-PNPs. Permeation parameters were calculated following ex vivo permeation study through rat skin. Transport of the PNPs across the skin layers was investigated using a fluorescence laser microscope. Results revealed that an optimized PNPs formulation was developed with a particle size 415.94 nm and EE 37.31%. Dapoxetine was successfully entrapped in the polymeric matrix. Chitosan and ALG interacted electrostatically with the studied cross-linking agents to form a polyelectrolyte complex. The ex vivo study illustrated a sustained release profile of DPX with enhanced skin permeation from the film loaded PNPs. Moreover, the PNPs was able to penetrate deeper into skin layers. Therefore, DPX transdermal film developed in this work could be considered as a successful drug delivery with better patient compliance for the treatment of PE.

Influence of the Preparation Method on Some Characteristics of Alginate/Chitosan/Lovastatin Composites

This study investigates the effects of direct and indirect dispersion methods for lovastatin solid dispersion (LSD) in alginate (AG)/chitosan (CS) composites on the characteristics and properties of the AG/CS/LSD composites. The preparation method significantly influences the structure, morphology, and LSD size distribution of the composites as well as the drug release of LSD from the samples. The differences in dispersion methods for LSD lead to differences in the interaction between the components, the structure, and the control drug release of LSD. Lovastatin was released from the samples containing LSD in two stages (a fast release stage and a slow release stage), and the drug release content prepared using the indirect method is lower than that prepared using the direct method in the same buffer solution. After 32 h of testing, the released LSD content from the indirect and direct LSD dispersion methods in pH 2 and pH 7.4 buffer solutions was 87–94% and 41–61%, respectively. Drug release kinetics from the above samples in solutions with different pH values was also set up.

Pharmacokinetic evaluation of differential drug release formulations of rabeprazole in dogs

Objectives: To develop novel dual release prototype capsule formulations of rabeprazole and evaluation of pharmacokinetic properties relative to the reference product (Aciphex^®) in Beagle dogs. Methods: The dual release prototype formulations of rabeprazole were developed by preparing optimized mini-tablets core which was subsequently coated with barrier/enteric coating using standard excipients. Both novel prototype formulations were subjected for in vitro release and assay by HPLC-UV to assess long term stability. Single dose pharmacokinetic study used a single sequence three treatments crossover design. In Periods 1 and 2, four dogs received oral 20 mg dose of two prototype formulations. In Period 3, all dogs received a 20 mg oral dose of Aciphex^® reference product. There was a 1-week washout time between two successive periods. A quantitative analysis of rabeprazole/sulfide metabolite in plasma samples was performed using a validated LC-MS/MS assay and PK parameters were estimated by non-compartmental analysis. Results: The stability of the prototype formulations was confirmed over a period of 24 months with an acceptable assay and dissolution data. One of the novel prototype formulations showed 70% oral bioavailability relative to the reference product. Despite a 30% reduced bioavailability, this showed 1 h delay in peak concentration, longer plasma residence time of rabeprazole (up to 12 h) and longer apparent elimination half-life. Conclusions: The use of a canine model has enabled the selection of a novel dual-release prototype formulation of rabeprazole for further clinical development.

In Vitro Drug Dissolution/Permeation Testing of Nanocarriers for Skin Application: a Comprehensive Review

This review highlights in vitro drug dissolution/permeation methods available for topical and transdermal nanocarriers that have been designed to modulate the propensity of drug release, drug penetration into skin, and permeation into systemic circulation. Presently, a few of USFDA-approved in vitro dissolution/permeation methods are available for skin product testing with no specific application to nanocarriers. Researchers are largely utilizing the in-house dissolution/permeation testing methods of nanocarriers. These drug release and permeation methods are pending to be standardized. Their biorelevance with reference to in vivo plasma concentration-time profiles requires further exploration to enable translation of in vitro data for in vivo or clinical performance prediction.

Optimized vinpocetine-loaded vitamin E D-α-tocopherol polyethylene glycol 1000 succinate-alpha lipoic acid micelles as a potential transdermal drug delivery system: in vitro and ex vivo studies

Background

Vinpocetine (VNP), a semisynthetic natural product, is used as a vasodilator for cerebrovascular and age-related memory disorders. VNP suffers from low oral bioavailability owing to its low water solubility and extensive first-pass metabolism. This work aimed at utilizing D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and alpha lipoic acid (ALA) to develop efficient micellar system for transdermal delivery of VNP.

Materials and methods

VNP-TPGS-ALA micelles were prepared, characterized for particle size using particle size analyzer, and investigated for structure using transmission electron microscope. Optimization of VNP-TPGS-ALA micelles-loaded transdermal films was performed using Box–Behnken experimental design. The investigated factors were percentage of ALA in TPGS (X₁), citral concentration (X₂), and propylene glycol concentration (X₃). Elongation percent (Y₁), initial permeation after 2 hours (Y₂), and cumulative permeation after 24 hours (Y₃) were studied as responses.

Results

Statistical analysis revealed optimum levels of 16.62%, 3%, and 2.18% for X₁, X₂, and X₃, respectively. Fluorescent laser microscopic visualization of skin penetration of the optimized transdermal film revealed marked widespread fluorescence intensity in skin tissue after 0.5, 2, and 4 hours compared with raw VNP transdermal film formulation, which indicated enhancement of VNP skin penetration.

Conclusion

The obtained results highlighted the potentiality of VNP nanostructure-based films for controlling the transdermal permeation of the drug and improving its effectiveness.

Biomaterials for drug delivery patches

The limited efficiency of conventional drugs has been instigated the development of new and more effective drug delivery systems (DDS). Transdermal DDS, are associated with numerous advantages such its painless application and less frequent replacement and greater flexibility of dosing, features that triggered the research and development of such devices. Such systems have been produced using either biopolymer; or synthetic polymers. Although the first ones are safer, biocompatible and present a controlled degradation by human enzymes or water, the second ones are the most currently available in the market due to their greater mechanical resistance and flexibility, and non-degradation over time. This review highlights the most recent advances (mainly in the last five years) of patches aimed for transdermal drug delivery, focusing on the different materials (natural, synthetic and blends) and latest designs for the development of such devices, emphasizing also their combination with drug carriers that enable enhanced drug solubility and a more controlled release of the drug over the time. The benefits and limitations of different patches formulations are considered with reference to their appliance to transdermal drug delivery. Furthermore, a record of the currently available patches on the market is given, featuring their most relevant characteristics. Finally, a list of most recent/ongoing clinical trials regarding the use of patches for skin disorders is detailed and critical insights on the current state of patches for transdermal drug delivery are also provided.

Temozolomide encapsulated and folic acid decorated chitosan nanoparticles for lung tumor targeting: improving therapeutic efficacy both in vitro and in vivo

Folic acid-conjugated temozolomide (TMZ)-loaded chitosan nanoparticles (CS-TMZ-FLA-NP) were developed to target lung cancer in the anticipation that folic acid would increase the affinity of nanoparticles for cancer cells. CS-TMZ-FLA-NP showed the highest anti-proliferative effect on the lung cancer cells in comparison to free TMZ and CS-TMZ-NP (nanoparticles without folic acid). A cellular uptake assay was performed on two different cell lines, L132 and A549. Cellular uptake efficiencies of CS-TMZ-NP and CS-TMZ-FLA-NP were found to be concentration-dependent in both cell lines. CS-TMZ-FLA-NP produced a 2.5 fold greater accumulation of TMZ than CS-TMZ-NP in both cell lines. CS-TMZ-FLA-NP maintained a significantly higher deposition of TMZ in lung tissue (approximately 7.5 μg/g of lung tissue) when compared to free TMZ and CS-TMZ-NP. Mice treated with CS-TMZ-FLA-NP had a 100% survival rate with significant suppression of tumor growth. Histopathological and immunohistochemical studies also demonstrated that CS-TMZ-FLA-NP had superior anticancer activity compared to the other two treatments. Our results indicate that CS-TMZ-FLA-NP can effectively facilitate targeting to human lung cancer cell lines in vitro and to lung tumors in vivo in a sustained manner and so improve the therapeutic efficacy of TMZ.

Nanomaterials for transdermal drug delivery: beyond the state of the art of liposomal structures

A wide range of biomedical materials have been proposed to meet the different needs for controlled oral or intravenous drug delivery. The advantages of oral delivery such as self-administration of a pre-determined drug dose at defined time intervals makes it the most convenient means for the delivery of small molecular drugs. It fails however to delivery therapeutic macromolecules due to rapid degradation in the stomach and size-limited transport across the epithelium. The primary mode of administration of macromolecules is presently via injection. This administration mode is not without limitations, as the invasive nature of injections elicits pain and decreases patients' compliance. Alternative routes for drug delivery have been looked for, one being the skin. Delivery of drugs via the skin is based on the therapeutics penetrating the stratum corneum (SC) with the advantage of overcoming first-pass metabolism of drugs, to deliver drugs with a short-half-life time more easily and to eliminate frequent administrations to maintain constant drug delivery. The transdermal market still remains limited to a narrow range of drugs. The low permeability of the SC to water-soluble and macromolecular drugs poses significant challenges to transdermal administration via passive diffusion through the skin, as is the case for all topically administered drug formulations intended to bring the therapeutic into the general circulation. To widen the scope of drugs for transdermal delivery, new procedures to enhance skin permeation to hydrophilic drugs and macromolecules are under development. Next to the integration of skin enhancers into pharmaceutical formulations, nanoparticles based on lipid carriers have been widely considered and reviewed. While being briefly reviewed here, the main focus of this article is on current advancements using polymeric and metallic nanoparticles. Next to these passive technologies, the handful of active technologies for local and systemic transdermal drug delivery will be discussed and put into perspective. While passive approaches dominate the literature and the transdermal market, active delivery based on microneedles or iontophoresis approaches have shown great promise for transdermal drug delivery and have entered the market, in the last decade. This review gives an overall idea of the current activities in this field.

Formulation and in vitro/in vivo evaluation of chitosan-based film forming gel containing ketoprofen

The film forming gel, adhered to skin surfaces upon application and formed a film, has an advantage onto skin to provide protection and continuous drug release to the application site. This study aimed to prepare a chitosan-based film forming gel containing ketoprofen (CbFG) and to evaluate the CbFG and film from CbFG (CbFG-film). CbFG were prepared with chitosan, lactic acid and various skin permeation enhancers. The physicochemical characteristics were evaluated by texture analysis, viscometry, SEM, DSC, XRD and FT-IR. To identify the mechanism of skin permeation, in vitro skin permeation study was conducted with a Franz diffusion cell and excised SD-rat and hairless mouse dorsal skin. In vivo efficacy assessment in mono-iodoacetate (MIA)-induced rheumatoid arthritis animal model was also conducted. CbFG was successfully prepared and, after applying CbFG to the excised rat dorsal skin, the CbFG-film was also formed well. The physicochemical characteristics of CbFG and CbFG-film could be explained by the grafting of oleic acid onto chitosan in the absence of catalysts. In addition, CbFG containing oleic acid had a higher skin permeation rate in comparison with any other candidate enhancers. The in vivo efficacy study also confirmed significant anti-inflammatory and analgesic effects. Consequently, we report the successful preparation of chitosan-based film forming gel containing ketoprofen with excellent mechanical properties, skin permeation and anti-inflammatory and analgesic effects.

Functionalised nanostructures for transdermal delivery of drug cargos

Nanotechnology has burgeoned over last decade exploring varieties of novel applications in all areas of science and technology. Utilisation of bio-friendly polymers for engineering nanostructures (NS) improves safety and efficacy in drug delivery. Biopolymers not merely employed for fabricating drug carriers but also leveraged for surface functionalisation of other NS to impart bio-mimicking properties. Biopolymer functionalised NS garnered researcher's attention because of their potential to enhance skin permeability of drug cargo. Biopolymers, i.e. cell-penetrating peptides (CPP), chitosan and hyaluronic acid not only enhance skin permeability but also add multiple functions due to their intrinsic biomimetic properties. This multifunctional drug delivery system is a promising tool to achieve skin delivery of large number of therapeutic agents. In this review, functionalisation of NS with biopolymers particularly polysaccharides and polypeptides is discussed in detail. In particular, applications of these functionalised NS for TDDS is elaborated. Moreover, this review provides framework for elaborating importance of functionalisation of NS to enhance skin permeability and depicts advantages of biopolymers to construct more biocompatible carriers for drug cargos.

Chitosan nanoparticles for nitric oxide delivery in human skin

The use of nanoparticle-based transdermal delivery systems is a promising approach to efficiently carry and deliver therapeutic agents for dermal and systemic administration. Nitric oxide (NO) is a key molecule that plays important roles in human skin such as the control of skin homeostasis, skin defense, control of dermal blood flow, and wound healing. In addition, human skin contains stores of NO derivatives that can be mobilized and release free NO upon UV irradiation with beneficial cardiovascular effects, for instance the control of blood pressure. In this work, the NO donor precursor glutathione (GSH) was encapsulated (encapsulation efficiency of 99.60%) into ultra-small chitosan nanoparticles (CS NPs) (hydrodynamic size of 30.65 ± 11.90 nm). GSH-CS NPs have a core-shell structure, as revealed by atomic force microscopy and X-ray photoelectron spectroscopy, in which GSH is protected in the nanoparticle core. Nitrosation of GSH by nitrous acid led to the formation of the NO donor S-nitrosogluthathione (GSNO) into CS NPs. The GSNO release from the CS NPs followed a Fickian diffusion described by the Higuchi mathematical model. Topical application of GSNO-CS NPs in intact human skin significantly increased the levels of NO and its derivatives in the epidermis, as assayed by confocal microscopy, and this effect was further enhanced by skin irradiation with UV light. Therefore, NO-releasing CS NPs are suitable materials for transdermal NO delivery to local and/or systemic therapies.

Omp16-based vaccine encapsulated by alginate-chitosan microspheres provides significant protection against Haemophilus parasuis in mice

Haemophilus parasuis (H. parasuis) is the etiological agent of swine Glässer's disease, which leads to significant economic loss in swine industry over the world. Subunit vaccine based on outer membrane protein is one of the promising choices to protect pigs against H. parasuis infection despite low immunity efficiency. In this paper, outer membrane protein 16 (Omp16) of H. parasuis encapsulated by alginate-chitosan microspheres as antigen carriers was explored for the first time in a mouse model. Our results showed that the microspheres with Omp16 induced significant higher H. parasuis-specific antibodies, and higher titers of IL-2, IL-4, and IFN-γ than those by Omp16-FIA in treated mice (p<0.05). Moreover, H. parasuis load in the tissues from liver, spleen, and lung of mice immunized with microspheres containing Omp16 was significantly decreased (p<0.05) than that in the same counterpart tissues of control groups. In addition, 80% mice treated with Omp16 and 70% mice with Omp16-FIA were survived after challenged with H. parasuis virulent strain LY02 (serovar 5). Therefore, Omp16-based microsphere vaccine induces both humoral and cellular immune responses and provides promising protection against H. parasuis infection in mice.

Chitosan nanoparticles in drug therapy of infectious and inflammatory diseases

INTRODUCTION

Chitosan, a polymer from the chitin family has diverse pharmaceutical and bio-medical utility because of its easy widespread availability, non-toxicity, biocompatibility, biodegradability, rich functionalities and high drug-loading capacity. Recent pharmaceutical research has examined the use of chitosan-based systems for drug delivery applications in various diseases. The availability of functional groups permits the conjugation of specific ligands and thus helps to target loaded drugs to the site of infection/inflammation. Slow biodegradation of chitosan permits controlled and sustained release of loaded moieties; reduces the dosing frequency and is useful for improving patient compliance in infectious drug therapy. The muco-adhesion offered by chitosan makes it an attractive candidate for anti-inflammatory drug delivery, where rapid clearance of the active moiety due to the increased tissue permeability is the major problem. The pH-dependent swelling and drug release properties of chitosan present a means of passive targeting of active drug moieties to inflammatory sites.

AREAS COVERED

Development of chitosan-based nanoparticulate systems for drug delivery applications is reviewed. The current state of chitosan-based nanosystems; with particular emphasis on drug therapy in inflammatory and infectious diseases is also covered.

EXPERT OPINION

The authors believe that chitosan-based nanosystems, due to the special and specific advantages, will have a promising role in the management of infectious and inflammatory diseases.

Preparation, characterization, and potential application of chitosan, chitosan derivatives, and chitosan metal nanoparticles in pharmaceutical drug delivery

Naturally occurring polymers, particularly of the polysaccharide type, have been used pharmaceutically for the delivery of a wide variety of therapeutic agents. Chitosan, the second abundant naturally occurring polysaccharide next to cellulose, is a biocompatible and biodegradable mucoadhesive polymer that has been extensively used in the preparation of micro-as well as nanoparticles. The prepared particles have been exploited as a potential carrier for different therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and nonparenteral administration. Therapeutic agent-loaded chitosan micro- or nanoparticles were found to be more stable, permeable, and bioactive. In this review, we are highlighting the different methods of preparation and characterization of chitosan micro- and nanoparticles, while reviewing the pharmaceutical applications of these particles in drug delivery. Moreover, the roles of chitosan derivatives and chitosan metal nanoparticles in drug delivery have been illustrated.

Solid lipid nanoparticles for transdermal delivery of avanafil: optimization, formulation, in-vitro and ex-vivo studies

CONTEXT

Avanafil (AVA) is used in the treatment of erectile dysfunction, but is reported for its poor aqueous solubility. Solid lipid nanoparticles (SLNs) are lipid carriers that can greatly enhance drug solubility and bioavailability.

OBJECTIVE

This work was aimed to formulate and optimize AVA SLNs with subsequent loading into hydrogel films for AVA transdermal delivery.

MATERIALS AND METHODS

AVA SLNs were prepared utilizing homogenization followed by ultra-sonication technique. The prepared SLNs were characterized for particle size, charge, surface morphology and drug content. The optimized SLNs formulation was incorporated into transdermal films prepared using HPMC and chitosan. Hydrogel films were evaluated for ex-vivo rat skin permeation using automated Franz diffusion cells. The permeation parameters and the release mechanism were evaluated. The transdermal permeation of the prepared AVA SLNs through the skin layers was studied using confocal laser scanning microscope.

RESULTS

Lipid concentration and % of oil in lipid had a pronounced effect on particle size while, entrapment efficiency was significantly affected by lipid concentration and % of cholesterol. The optimized AVA SLNs showed particle size and entrapment efficiency of 86 nm and 85.01%, respectively. TEM images revealed spherecity of the particles. High permeation parameters were observed from HPMC films loaded with AVA SLNs. The release data were in favor of Higuchi diffusion model. The prepared AVA SLNs were able to penetrate deeper in skin layers.

CONCLUSION

HPMC transdermal film-loaded AVA SLNs is an effective and alternative to per-oral drug administration.

Development of oral dispersible tablets containing prednisolone nanoparticles for the management of pediatric asthma

The purpose of the present study was to develop oral dispersible tablets containing prednisolone (PDS)-loaded chitosan nanoparticles using microcrystalline cellulose (MCC 101), lactose, and croscarmellose sodium (CCS). The PDS-loaded chitosan nanoparticles were formulated by ionotropic external gelation technique in order to enhance the solubility of PDS in salivary pH. Prepared nanoparticles were used for the development of oral fast disintegrating tablets by direct compression method. The prepared tablets were evaluated for disintegration time (DT), in vitro drug release (DR), thickness, weight variation, drug content uniformity, friability, and hardness. The effect of concentrations of the dependent variables (MCC, lactose, CCS) on DT and in vitro DR was studied. Fast disintegrating tablets of PDS can be prepared by using MCC, CCS, and lactose with enhanced solubility of PDS. The minimum DT was found to be 15 seconds, and the maximum DR within 30 minutes was 98.50%. All independent variables selected for the study were statistically significant. Oral fast disintegrating tablets containing PDS nanoparticles could be the better choice for the pediatric patients that would result in better patient compliance. From this study, it can be concluded that fast disintegrating tablets could be a potential drug delivery technology for the management of asthma in pediatrics.

Matrix-type transdermal films to enhance simvastatin ex vivo skin permeability

This study aimed at employing Plackett-Burman design in screening formulation variables that affect quality of matrix-type simvastatin (SMV) transdermal film. To achieve this goal, 12 formulations were prepared by casting method. The investigated variables were Eudragit RL percentage, polymer mixture percentage, plasticizer type, plasticizer percentage, enhancer type, enhancer percentage and dichloromethane fraction in organic phase. The films were evaluated for physicochemical properties and ex vivo SMV permeation. SMV initial, delayed flux, diffusivity and permeability coefficient were calculated on the delayed flux phase with constraint to minimize the initial flux and approaching steady-state flux. The obtained results revealed flat films with homogeneous distribution of SMV within the films. Thickness values changed from 65 to 180 μm by changing the factors' combinations. Most of the permeation profiles showed sustained release feature with fast permeation phase followed by slow phase. Analysis of variance (ANOVA) showed significant effects (p < 0.05) of the investigated variables on the responses with Prob > F values of 0.0147, 0.0814, 0.0063 and 0.0142 for the initial and delayed fluxes, permeability coefficients and diffusivities, respectively. The findings of screening study showed the importance of the significant variables to be scaled up for full optimization study as a promising alternative drug delivery system.

In vitro skin models as a tool in optimization of drug formulation

(Trans)dermal drug therapy is gaining increasing importance in the modern drug development. To fully utilize the potential of this route, it is important to optimize the delivery of active ingredient/drug into/through the skin. The optimal carrier/vehicle can enhance the desired outcome of the therapy therefore the optimization of skin formulations is often included in the early stages of the product development. A rational approach in designing and optimizing skin formulations requires well-defined skin models, able to identify and evaluate the intrinsic properties of the formulation. Most of the current optimization relies on the use of suitable ex vivo animal/human models. However, increasing restrictions in use and handling of animals and human skin stimulated the search for suitable artificial skin models. This review attempts to provide an unbiased overview of the most commonly used models, with emphasis on their limitations and advantages. The choice of the most applicable in vitro model for the particular purpose should be based on the interplay between the availability, easiness of the use, cost and the respective limitations.

Optimization of caseinate-coated simvastatin-zein nanoparticles: improved bioavailability and modified release characteristics

The current study focuses on utilization of the natural biocompatible polymer zein to formulate simvastatin (SMV) nanoparticles coated with caseinate, to improve solubility and hence bioavailability, and in addition, to modify SMV-release characteristics. This formulation can be utilized for oral or possible depot parenteral applications. Fifteen formulations were prepared by liquid–liquid phase separation method, according to the Box–Behnken design, to optimize formulation variables. Sodium caseinate was used as an electrosteric stabilizer. The factors studied were: percentage of SMV in the SMV-zein mixture (X₁), ethanol concentration (X₂), and caseinate concentration (X₃). The selected dependent variables were mean particle size (Y₁), SMV encapsulation efficiency (Y₂), and cumulative percentage of drug permeated after 1 hour (Y₃). The diffusion of SMV from the prepared nanoparticles specified by the design was carried out using an automated Franz diffusion cell apparatus. The optimized SMV-zein formula was investigated for in vivo pharmacokinetic parameters compared with an oral SMV suspension. The optimized nanosized SMV-zein formula showed a 131 nm mean particle size and 89% encapsulation efficiency. In vitro permeation studies displayed delayed permeation characteristics, with about 42% and 85% of SMV cumulative amount released after 12 and 48 hours, respectively. Bioavailability estimation in rats revealed an augmentation in SMV bioavailability from the optimized SMV-zein formulation, by fourfold relative to SMV suspension. Formulation of caseinate-coated SMV-zein nanoparticles improves the pharmacokinetic profile and bioavailability of SMV. Accordingly, improved hypolipidemic activities for longer duration could be achieved. In addition, the reduced dosage rate of SMV-zein nanoparticles improves patient tolerability and compliance.