Ex vivo skin delivery of diclofenac by transcutol containing liposomes and suggested mechanism of vesicle-skin interaction

Lab on chip based self-adjustable liposomes for rapid wound healing: An in depth in vitro, in vivo and higher dose toxicity investigation

Thanks to microfluidic technology, different nano-delivery systems are becoming clinically viable. Using a novel and rapid microfluidic hydrodynamic focusing (MHF) method (lipids on chip) we developed self-adaptable liposomes (SLs) containing cefpodoxime proxetil (CP) for the treatment of skin infections caused by Staphylococcus aureus. SLs were optimized using different flow rate ratios in the MHF method and the final formulation CPT3 was found to be the best in terms of particle size (68.27 ± 01.15 nm), % entrapment efficiency (% EE: 82 ± 1.5), polydispersity (PDI: 0.2 ± 0.012), and degree of deformability (DOD: 4.7 ± 0.18 nm). Rats (Sprague Dawley) treated with a self-adaptable CPT3 liposomal formulation recuperate skin injury, exhibited reduced bacterial counts (<106 CFU/mL) in the wounded region, and completely restored (100 %) on day 21. Rat survival, in vivo dermal pharmacokinetics and ex vivo-in vivo relationship were also investigated. Rats treated with an even 10-fold higher dose (100 mg/kg/day) of CP using an equivalent CPT3 formulation did not show any symptoms of toxicity as revealed by hematological, biochemical, and internal organ assessment observations. Finally, the developed CPT3 formulation with special interest in patients with high-risk skin injuries not only delivered CP in a controlled manner but was also clinically effective and safe as it did not produce any serious adverse events even at 10× higher doses in the infected rats.

Transferosomes as a transdermal drug delivery system: Dermal kinetics and recent developments

The development of innovative approaches to deliver medications has been growing now for the last few decades and generates a growing interest in the dermatopharmaceutical field. Transdermal drug delivery in particular, remains an attractive alternative route for many therapeutics. However, due to the limitations posed by the barrier properties of the stratum corneum, the delivery of many pharmaceutical dosage forms remains a challenge. Most successful therapies using the transdermal route have been ones containing smaller lipophilic molecules with molecular weights of a few hundred Daltons. To overcome these limitations of size and lipophilicity of the drugs, transferosomes have emerged as a successful tool for transdermal delivery of a variety of therapeutics including hydrophilic actives, larger molecules, peptides, proteins, and nucleic acids. Transferosomes exhibit a flexible structure and higher surface hydrophilicity which both play a critical role in the transport of drugs and other solutes using hydration gradients as a driving force to deliver the molecules into and across the skin. This results in enhanced overall permeation as well as controlled release of the drug in the skin layers. Additionally, the physical-chemical properties of the transferosomes provide increased stability by preventing degradation of the actives by oxidation, light, and temperature. Here, we present the history of transferosomes from solid lipid nanoparticles and liposomes, their physical-chemical properties, dermal kinetics, and their recent advances as marketed dosage forms. This article is categorized under: Biology-Inspired Nanomaterials > Lipid-Based Structures Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Influence of Poloxamer 188 on Anti-Inflammatory and Analgesic Effects of Diclofenac-Loaded Nanoemulsion: Formulation, Optimization and in Vitro/in Vivo Evaluation

In this study, a polymer-stabilized nanoemulsion (PNE) was developed to improve the inflammatory and analgesic activities of diclofenac (DA). DA-PNEs were prepared from sesame oil and poloxamer 188 (P188), polysorbate 80, and span 80 as emulsifiers and optimized by a systematic multi-objective optimization method. The developed DA-PNEs exhibited thermodynamical stability with low viscosity. The mean diameter, PDI, surface charge, and entrapment efficiency of DA-PNEs were 122.49±3.42 nm, 0.226±0.08, -47.3 ± 3.6 mV, and 93.57±3.4 %, respectively. The cumulative in vitro release profile of DA-PNEs was significantly higher than the neat drug in simulated gastrointestinal fluids. The anti-inflammatory activities of DA-PNEs were evaluated in the λ-carrageenan-induced paw edema model. To investigate the effect of P188 on analgesic and anti-inflammatory activities, a formulation without P188 was also prepared and named DA-NEs. Following oral administration, DA-PNEs showed a significantly higher (p<0.05) effect in reducing pain and inflammation symptoms as compared to free diclofenac and DA-NEs. Moreover, histopathological examination confirmed that DA-PNEs meaningfully reduced the extent of paw edema, comparable to that of DA. Taken together, the findings of the in vitro and in vivo studies suggest that diclofenac-loaded P188-stabilized nanoemulsion can be considered a potential drug delivery system for treating and controlling inflammatory disorders and alleviating pains.

Curcumin Transferosome-Loaded Thermosensitive Intranasal in situ Gel as Prospective Antiviral Therapy for SARS-Cov-2

Purpose

Immunomodulatory and broad-spectrum antiviral activities have motivated the evaluation of curcumin for Coronavirus infection 2019 (COVID-19) management. Inadequate bioavailability is the main impediment to the therapeutic effects of oral Cur. This study aimed to develop an optimal curcumin transferosome-loaded thermosensitive in situ gel to improve its delivery to the lungs.

Methods

Transferosomes were developed by using 33 screening layouts. The phospholipid concentration as well as the concentration and type of surfactant were considered independent variables. The entrapment efficiency (EE%), size, surface charge, and polydispersity index (PDI) were regarded as dependent factors. A cold technique was employed to develop thermosensitive in-situ gels. Optimized transferosomes were loaded onto the selected gels. The produced gel was assessed based on shape attributes, ex vivo permeability enhancement, and the safety of the nasal mucosa. The in vitro cytotoxicity, antiviral cytopathic effect, and plaque assay (CV/CPE/Plaque activity), and in vivo performance were evaluated after intranasal administration in experimental rabbits.

Results

The optimized preparation displayed a particle size of 664.3 ± 69.3 nm, EE% of 82.8 ± 0.02%, ZP of -11.23 ± 2.5 mV, and PDI of 0.6 ± 0.03. The in vitro curcumin release from the optimized transferosomal gel was markedly improved compared with that of the free drug-loaded gel. An ex vivo permeation study revealed a significant improvement (2.58-fold) in drug permeability across nasal tissues of sheep. Histopathological screening confirmed the safety of these preparations. This formulation showed high antiviral activity against SARS-CoV-2 at reduced concentrations. High relative bioavailability (226.45%) was attained after the formula intranasally administered to rabbits compared to the free drug in-situ gel. The curcumin transferosome gel displayed a relatively high lung accumulation after intranasal administration.

Conclusion

This study provides a promising formulation for the antiviral treatment of COVID-19 patients, which can be evaluated further in preclinical and clinical studies.

Skin drug delivery using lipid vesicles: A starting guideline for their development

Lipid vesicles can provide a cost-effective enhancement of skin drug absorption when vesicle production process is optimised. It is an important challenge to design the ideal vesicle, since their properties and features are related, as changes in one affect the others. Here, we review the main components, preparation and characterization methods commonly used, and the key properties that lead to highly efficient vesicles for transdermal drug delivery purposes. We stand by size, deformability degree and drug loading, as the most important vesicle features that determine the further transdermal drug absorption. The interest in this technology is increasing, as demonstrated by the exponential growth of publications on the topic. Although long-term preservation and scalability issues have limited the commercialization of lipid vesicle products, freeze-drying and modern escalation methods overcome these difficulties, thus predicting a higher use of these technologies in the market and clinical practice.

Biocompatible phospholipid-based nanovesicular drug delivery system of ketoprofen: Systematic development, optimization, and preclinical evaluation

The present work involved development of phospholipid-based permeation enhancing nanovesicles (PENVs) for topical delivery of ketoprofen. Screening of phospholipids and process parameters was performed. Central composite design was used for optimization of factors, that is, amount (%, w/w) of phospholipid and ethanol at three levels. The optimized nanovesicles (NVs) were loaded with different terpenes and then incorporated into a gel base. Optimized NVs exhibited 69% entrapment efficiency, 51% transmittance, 328 nm mean vesicle size, and polydispersity index of 0.25. In vitro release kinetics evaluation indicated best fitting as per Korsemeyer-Peppa's model and drug release via Fickian-diffusion mechanism. The optimized NVs loaded with mint terpene showed minimal degree of deformability and maximal elasticity as compared with the conventional NVs and liposomes. Rheology and texture analysis indicated pseudoplastic flow and smooth texture of the vesicle gel formulation. Ex vivo permeation studies across Wistar rat skin indicated low penetration (0.43-fold decrease) and high skin retention (4.26-fold increase) of ketoprofen from the optimized PENVs gel vis-à-vis the conventional gel. Skin irritancy study indicated lower scores for PENVs gel construing its biocompatible nature. Stability studies confirmed cold storage is best suitable for vesicle gel, and optimized PENVs were found to be suitable for topical delivery of ketoprofen.

Improved Topical Drug Delivery: Role of Permeation Enhancers and Advanced Approaches

The delivery of drugs via transdermal routes is an attractive approach due to ease of administration, bypassing of the first-pass metabolism, and the large skin surface area. However, a major drawback is an inability to surmount the skin's stratum corneum (SC) layer. Therefore, techniques reversibly modifying the stratum corneum have been a classical approach. Surmounting the significant barrier properties of the skin in a well-organised, momentary, and harmless approach is still challenging. Chemical permeation enhancers (CPEs) with higher activity are associated with certain side effects restricting their advancement in transdermal drug delivery. Furthermore, complexity in the interaction of CPEs with the skin has led to difficulty in elucidating the mechanism of action. Nevertheless, CPEs-aided transdermal drug delivery will accomplish its full potential due to advancements in analytical techniques, synthetic chemistry, and combinatorial studies. This review focused on techniques such as drug-vehicle interaction, vesicles and their analogues, and novel CPEs such as lipid synthesis inhibitors (LSIs), cell-penetrating peptides (CPPs), and ionic liquids (ILs). In addition, different types of microneedles, including 3D-printed microneedles, have been focused on in this review.

Liposome and microemulsion loaded with ibuprofen: from preparation to mechanism of drug transport

To compare the difference between liposome (LP) and microemulsion (ME) in delivering ibuprofen (IBU) transdermally and explore relative mechanism. IBU-LP and IBU-ME were prepared by ethanol injection and spontaneous emulsification, respectively. The percutaneous delivery was evaluated using Franz diffusion cells. Fourier transform infra-red spectroscopy (FTIR), differential scanning calorimetry (DSC), activation energy (Ea), and confocal laser scanning microscopy (CLSM) were used to investigate the transdermal mechanism. The particle size and encapsulation efficiency were 228.00 ± 8.60 nm, 86.68 ± 1.43%(w/w) for IBU-LP, and 56.74 ± 7.11 nm, 91.08 ± 3.27%(w/w) for IBU-ME. Percutaneous study showed that formulations enhanced permeation and drug retention in the skin. FTIR and DSC showed that the permeation occurred due to the interaction of the formulations with the lipid bilayer and the protein. The decrease in Ea (1.506 and 0.939 kcal/mol) revealed that the stratum corneum (SC) lipid bilayers were significantly disrupted and this destructive effect of IBU-LP was stronger. IBU-LP was superior to IBU-ME in the aspects of transdermal delivery of IBU.

Glycerosomal thermosensitive in situ gel of duloxetine HCl as a novel nanoplatform for rectal delivery: in vitro optimization and in vivo appraisal

Duloxetine HCl (DXH) is a reuptake inhibitor of serotonin and norepinephrine used to treat the major depressive disorder. Following its extensive hepatic metabolism, acid-labile nature, and limited aqueous solubility, DXH has poor oral bioavailability (40%). The rectal route has been suggested as another route of administration to surmount such challenges. The present study aimed to prepare DXH-loaded glycerosomal (DXH-GLYS) in situ gel for rectal administration to increase DXH permeability and improve its bioavailability. Box-Behnken design (BBD) was adopted to prepare and optimize nanoglycerosomes. The impact of Phospholipon 90G (PL90G), Tween 80 concentrations, and glycerol percentage on encapsulation efficiency, nanoglycerosomal size, % cumulative DXH released, and the cumulative DXH permeated per unit area after 24 h were studied by the design. The pharmacokinetic and pharmacodynamic behavior of optimized formulation was investigated in rats. The formulated DXH-GLYS had a vesicle size ranging between 135.9 and 430.6 nm and an entrapment efficiency between 69.11 and 98.12%. The permeation experiment revealed that the optimized DXH-GLYS in situ gel increased DXH permeation by 2.62-fold compared to DXH solution. Pharmacokinetics studies disclosed that the DXH-GLYS in situ rectal gel exhibited 2.24-times increment in DXH bioavailability relative to oral DXH solution. The pharmacodynamic study revealed that the DXH-GLYS rectal treatment significantly improved the behavioral analysis parameters and was more efficacious as an antidepressant than the oral DXH solution. Collectively, these findings demonstrate that GLYS can be considered a potentially valuable rectal nanocarrier that could boost the DXH efficacy.

Fenticonazole nitrate loaded trans-novasomes for effective management of tinea corporis: design characterization, in silico study, and exploratory clinical appraisal

The current investigation aimed for loading fenticonazole nitrate (FTN), an antifungal agent with low aqueous solubility, into trans-novasomes (TNs) for management of tinea corporis topically. TNs contain Brij^® as an edge activator besides the components of novasomes (cholesterol, Span 60, and oleic acid) owing to augment the topical delivery of FTN. TNs were fabricated applying ethanol injection method based on D-optimal experiment. TNs were evaluated with regard to entrapment efficiency percent (EE%), particle size (PS), polydispersity index (PDI), and zeta potential (ZP). Further explorations were conducted on the optimum formulation (F7). F7 showed spherical appearance with EE%, PS, PDI, and ZP of 100.00 ± 1.10%, 358.60 ± 10.76 nm, 0.51 ± 0.004, and −30.00 ± 0.80 mV, respectively. The in silico study revealed the ability of the FTN–cholesterol complex to maintain favorable interactions throughout the molecular dynamics simulation (MDS) study. Moreover, Trichophyton mentagrophytes growth was inhibited effectively by F7 than by FTN suspension applying 2,3-bis(2-methyloxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) reduction assay. Furthermore, a clinical appraisal on patients with tinea corporis fungal lesions confirmed the superiority of F7 compared to Miconaz^® cream in the magnitude of clinical cure of tinea corporis. Thereby, TNs could be considered as promising vesicles for enhancing the antifungal potential of FTN for the topical management of tinea corporis.

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.

Design and development of topical liposomal formulations in a regulatory perspective

The skin is the absorption site for drug substances intended to treat loco-regional diseases, although its barrier properties limit the permeation of drug molecules. The growing knowledge of the skin structure and its physiology have supported the design of innovative nanosystems (e.g. liposomal systems) to improve the absorption of poorly skin-permeable drugs. However, despite the dozens of clinical trials started, few topically applied liposomal systems have been authorized both in the EU and the USA. Indeed, the intrinsic complexity of the topically applied liposomal systems, the higher production costs, the lack of standardized methods and the more stringent guidelines for assessing their benefit/risk balance can be seen as causes of such inefficient translation. The present work aimed to provide an overview of the physicochemical and biopharmaceutical characterization methods that can be applied to topical liposomal systems intended to be marketed as medicinal products, and the current regulatory provisions. The discussion highlights how such methodologies can be relevant for defining the critical quality attributes of the final product, and they can be usefully applied based on the phase of the life cycle of a liposomal product: to guide the formulation studies in the early stages of development, to rationally design preclinical and clinical trials, to support the pharmaceutical quality control system and to sustain post-marketing variations. The provided information can help define harmonized quality standards able to overcome the case-by-case approach currently applied by regulatory agencies in assessing the benefit/risk of the topically applied liposomal systems.

Elastic and Ultradeformable Liposomes for Transdermal Delivery of Active Pharmaceutical Ingredients (APIs)

Administration of active pharmaceutical ingredients (APIs) through the skin, by means of topical drug delivery systems, is an advanced therapeutic approach. As the skin is the largest organ of the human body, primarily acting as a natural protective barrier against permeation of xenobiotics, specific strategies to overcome this barrier are needed. Liposomes are nanometric-sized delivery systems composed of phospholipids, which are key components of cell membranes, making liposomes well tolerated and devoid of toxicity. As their lipid compositions are similar to those of the skin, liposomes are used as topical, dermal, and transdermal delivery systems. However, permeation of the first generation of liposomes through the skin posed some limitations; thus, a second generation of liposomes has emerged, overcoming permeability problems. Various mechanisms of permeation/penetration of elastic/ultra-deformable liposomes into the skin have been proposed; however, debate continues on their extent/mechanisms of permeation/penetration. In vivo bioavailability of an API administered in the form of ultra-deformable liposomes is similar to the bioavailability achieved when the same API is administered in the form of a solution by subcutaneous or epi-cutaneous injection, which demonstrates their applicability in transdermal drug delivery.

Enhanced Transdermal Delivery of Bisoprolol Hemifumarate via Combined Effect of Iontophoresis and Chemical Enhancers: Ex Vivo Permeation/In Vivo Pharmacokinetic Studies

Bisoprolol hemifumarate (BH) is an antihypertensive drug that is used as first-line treatment for chronic hypertension and angina pectoris. Our study was performed to enhance the transdermal delivery of BH, a hydrophilic drug active with high molecular weight, through differently prepared hydrogels. The synergistic effect of permeation enhancers and iontophoresis was investigated via both ex vivo and in vivo permeation studies. Ex vivo iontophoretic permeation studies were performed by using male albino Wistar rat skin. Cellosolve® hydrogel (F7) showed a 1.5-fold increase in Q180, Jss, and FER compared to F5 (lacking permeation enhancer). BH pharmacokinetic data were studied in human volunteers, following transdermal delivery of F7, using Phoresor® Unit II iontophoresis device, compared to conventional oral tablets. F7 showed 1.9- and 2-fold higher values of Cmax and AUC0-40, respectively compared to Concor® tablets, as well as a smaller Tmax (2.00 ± 2.00 h). The relative bioavailability of F7 was found to be 201.44%, relative to Concor® tablets, demonstrating the significantly enhanced transdermal permeation of BH from the selected hydrogel by iontophoresis, in human volunteers. Finally, results showed the successful utility of permeation enhancers combined with iontophoresis in significantly enhanced transdermal permeation of BH, despite its large molecular weight and hydrophilic nature. Therefore, this strategy could be employed as a successful alternative route of administration to conventional oral tablets.

Nanoliposomes@Transcutol for In Vitro Skin Delivery of 8-Methoxypsoralen

8-methoxypsoralen is the most common drug in psoralen plus ultraviolet light irradiation therapy for the treatment of severe psoriasis. Despite of the efficacy, its classic oral administration leads to several serious adverse effects. However, the topical psoralen application produces a drug skin accumulation lower than that obtained by oral administration, due to the drug low skin permeability. In this paper, 8-methoxypsoralen loaded Penetration Enhancer-containing Vesicles were prepared using soy phosphatidylcholine and the penetration enhancer Transcutol® (5% or 10%) and characterized in terms of size, polydispersity index, zeta potential and encapsulation efficiency. No statistically significant differences in both size (~135 nm) and encapsulation efficiency (~65%) were found for different Transcutol® concentration. Transdermal delivery study assessed by Franz diffusion cells, showed that the 8-methoxypsoralen mainly accumulated into the stratum corneum. Moreover, after Penetration Enhancer-containing Vesicles application, the drug recovered in this layer is almost double of that delivered by conventional liposomes, while no significant difference was found from the different Transcutol® concentrations. Finally, biocompatibility checked by an MTT assay, demonstrated that the incubation of human keratinocytes for 24 h with 8-methoxypsoralen loaded Penetration Enhancer-containing Vesicles did not significantly reduce cell viability.

Development of Microemulsions Containing Glochidion wallichianum Leaf Extract and Potential for Transdermal and Topical Skin Delivery of Gallic Acid

Glochidion wallichianum (GW) is a good source of antioxidants, including gallic acid, promoting its development as a microemulsion. We constructed five pseudo-ternary phase diagrams comprising isopropyl myristate (IPM), water, and surfactant mixture (Smix)—i.e., Labrasol®:HCO-40® (1:1) with Transcutol® (1:1, 2:1, 3:1), and Tween80:Span80 (3:2) with Transcutol® or propylene glycol:ethanol (1:1). Additionally, blank and GW extract-loaded microemulsions were prepared at an IPM:Water:Smix ratio of 10:30:60 (high water content) and 30:10:60 (high oil content) from each Smix. The physical characteristics, skin permeation, and disposition were evaluated. The formulations with high water content and conductivities provided higher gallic acid permeation and disposition than those with high oil content. The Smix of Labrasol®:HCO-40® (1:1) and Transcutol® (1:1) promoted the highest gallic acid permeation (enhancement ratio 1.78 ± 0.12) and was suitable for transdermal delivery. However, the 1% hydroxypropyl methylcellulose control gel, the microemulsion with Smix of Labrasol®:HCO-40® (1:1) with Transcutol® (2:1), and Smix of Tween80:Span80 (3:2) with propylene glycol:ethanol (1:1) could provide higher skin accumulation of gallic acid than that with other formulations. The microstructures, ratio of surfactant:cosurfactant, and compositions of microemulsions were found to affect the skin permeation and disposition of gallic acid and require optimization to act as transdermal or topical delivery carriers.

Transcutol® P Containing SLNs for Improving 8-Methoxypsoralen Skin Delivery

Topical psoralens plus ultraviolet A radiation (PUVA) therapy consists in the topical application of 8-methoxypsoralen (8-MOP) followed by the skin irradiation with ultraviolet A radiation. The employment of classical 8-MOP vehicles in topical PUVA therapy is associated with poor skin deposition and weak skin permeability of psoralens, thus requiring frequent drug administration. The aim of the present work was to formulate solid lipid nanoparticles (SLNs) able to increase the skin permeation of 8-MOP. For this purpose, the penetration enhancer Transcutol^® P (TRC) was added to the SLN formulation. SLNs were characterized with respect to size, polydispersity index, zeta potential, entrapment efficiency, morphology, stability, and biocompatibility. Finally, 8-MOP skin diffusion and distribution within the skin layers was investigated using Franz cells and newborn pig skin. Freshly prepared nanoparticles showed spherical shape, mean diameters ranging between 120 and 133 nm, a fairly narrow size distribution, highly negative ζ potential values, and high entrapment efficiency. Empty and loaded formulations were almost stable over 30 days. In vitro penetration and permeation studies demonstrated a greater 8-MOP accumulation in each skin layer after SLN TRC 2% and TRC 4% application than that after SLN TRC 0% application. Finally, the results of experiments on 3T3 fibroblasts showed that the incorporation of TRC into SLNs could enhance the cellular uptake of nanoparticles, but it did not increase their cytotoxicity.

Preparation and in vitro / in vivo evaluation of flurbiprofen nanosuspension-based gel for dermal application

Flurbiprofen (FB) is an analgesic and anti-inflammatory drug, but its low water solubility (BCS Class II) limits its dermal bioavailability. The aim of this study is to develop a FB nanosuspension (NS) based gel and to evaluate its analgesic and anti-inflammatory activities in rats. FB-NS was produced by the wet milling method with Plantacare 2000^Ⓡ, as stabilizer. The FB-NS was then incorporated in different carrier gels such as hydroxypropyl methyl cellulose (HPMC), polycarbophil, oleogel, and chitosan. To select the optimum gel type, visual examinations, pH and rheological property measurements, texture profile analysis, in vitro release and ex vivo permeation studies were performed. Following these tests, the analgesic and anti-inflammatory activities of the optimum NS based gel were evaluated using the tail flick and carrageenan-induced paw edema methods consecutively. The NS was successfully prepared with the wet milling method, and the PS, PDI and ZP values were found to be 237.7 ± 6.8 nm, 0.133±0.030, and -30.4 ± 0.7 mV; respectively. Among the NS-based gels, HPMC gel showed more suitable rheological and mechanical properties, also the percentage of permeated FB and the flux value observed for HPMC gel were higher for HPMC than for the other gels. Thus, HPMC gel was selected as a carrier gel for in vivo pharmacodynamics studies. The anti-inflammatory activity of FB-NS HPMC gel was higher than that of the physical mixture gel and that of the coarse suspension gel. Results of our analgesic activity studies showed that, in the 180th min of FB nanosuspension treatment, the latency time was significantly prolonged compared to that of the control group (p<0.05). As a conclusion, while nanosuspensions increased the in vivo pharmacodynamics effect of FB by means of nanosized particles and a large surface area, the HPMC gel as a carrier prolonged the contact time of NSs with skin and eased the dermal application.

Polyoliposomes: novel polyol-modified lipidic nanovesicles for dermal and transdermal delivery of drugs

Various lipid nanovesicular systems have been developed with the aim to enhance the delivery of drugs via transdermal route. However, their clinical applications are often limited due to the barrier nature of skin and lack of flexibility. Herein, we have modified the conventional nanoliposomes (CLs) prepared by a thin-film hydration method by the addition of a polyol (glycerol) to form novel lipid nanovesicular structures termed 'POLYOLIPOSOMES' (PLs). They were further named as PL-B (before film formation) and PL-A (after film formation), depending on the stage of glycerol addition during production. Optimized CLs, PL-B and PL-A showed spherical nanovesicles and hydrodynamic diameter of 181.3 ± 4.11 nm, 114.2 ± 7.21 nm and 170.2 ± 6.51 nm, respectively. PLs showed significantly higher % entrapment efficiency and deformability index in comparison to CLs, indicating their higher flexibility. Furthermore, DSC and attenuated total relection (ATR)-Fourier transform infrared (FTIR) studies revealed the intercalation of glycerol into the lipid bilayer of PLs and interaction between nanovesicles and skin. Moreover, ex vivo and in vivo skin permeation studies confirmed the enhanced drug delivery of PLs via the transdermal route. Taken together, these results illustrate the potential of PLs as a novel lipid nanovesicular system for drug delivery via the transdermal route for both systematic (PL-B) as well as cutaneous diseases (PL-A).

Possibilities of the microemulsion use as indomethacin solubilizer and its effect on in vitro and ex vivo drug permeation from dermal gels in comparison with transcutol®

OBJECTIVE

Transcutol^® is a perfect solubilizer and an effective permeation enhancer of many active substances commonly used in cosmetics. Microemulsions due to the content of surfactant and co-surfactant could be also considered as chemical permeation enhancers that may support transdermal delivery of poorly water- soluble drugs. The purpose of this study was to investigate the effect of Transcutol^® and potential microemulsions on diffusion of poorly soluble indomethacin through an artificial membrane and excised rat skin.

METHODS

After drug solubilization in different enhancers, drug was dispersed in sodium alginate or carbopol gel used as dermal basis. For characterization of the microemulsions, the basic physico-chemical properties were determined. In vitro as well as ex vivo drug release was determined by vertical Franz cells.

RESULTS

Enhancing effect of the examined microemulsions was observed only in carbopol gel. There was an increase in cumulative drug amount released through synthetic membrane by 37.7-39.8% from the microemulsion formulation and 90.6% from Transcutol^® formulation within 6 h compared to the control samples. The differences between the permeation curves with or without the content of the enhancers were statistically significant (p < .05). Pearson correlation coefficients indicate a very high degree of dependence (r > 0.9) between in vitro and ex vivo drug release from all dermal vehicles used.

CONCLUSION

It can be stated that Transcutol^® is the best solubilizer and also penetration enhancer from the examined, and therefore it seems to be effective excipient/solubilizer in topical IND formulation.

Lipid vesicles: A versatile drug delivery platform for dermal and transdermal applications

Topical and transdermal application of active pharmaceutical ingredients to the skin is an attractive strategy being explored by formulation scientists to treat disease conditions rather than the oral drug delivery. Several approaches have been attempted, and many of them have emerged with significant clinical potential. However, the delivery of drugs across the skin is an arduous task due to permeation limiting barriers. It, therefore, requires the aid of external agents or carrier systems for efficient permeation. Lipid-based vesicular systems are carriers for the transport of drugs through the stratum corneum (dermal drug delivery) and into the bloodstream for systemic action (transdermal drug delivery) overcoming the barrier properties. This review article describes the various vesicular systems reported for skin delivery of actives with relevant case studies. The vesicular systems presented here are in the order of their advent from conventional systems to the advanced lipid vesicles. The design and development of drugs in vesicular systems have brought a new dimension to the treatment of disease conditions overcoming the permeation limiting barriers, thus improving its efficacy.

Mometasone furoate-loaded aspasomal gel for topical treatment of psoriasis: formulation, optimization, in vitro and in vivo performance

BACKGROUND

Present investigation was aimed to develop aspasomal gel of Mometasone Furoate for the treatment of Psoriasis that are biologically active and deliver drug at controlled rate and decrease dosing frequency.

METHODS

The vesicles were fabricated using film hydration method and optimized using 32 factorial Design. Prepared formulations were evaluated for percent drug loading, vesicle size, Zeta potential, polydispersity index and morphological studies. Gel was prepared using carbopol by loading optimized drug loaded asposomes and was evaluated for drug content, pH, viscosity and spreadability. The drug release study from the gel was done using dialysis membrane and goat skin. Anti- oxidant potency of the prepared aspasomal gel was determined by Ferric Reducing Assay whereas, in-vivo performance for inflammation and skin irritation was carried out using Wistar rats.

RESULTS

Optimized aspasomes demonstrated desired properties for entrapment efficiency (74.72 ± 1.8), vesicle size (282.9 ± 1.7), polydispersity index (0.2), zeta potential (-20.2 mV) with spherical shape. The results recorded for drug release from the optimized aspasomal gel exhibited sustained release (24h) compared to the marketed cream (5h). Depot formation of Mometasone furoate loaded aspasomal gel in the epidermis was confirmed by ex vivo skin penetration study by using fluorescent marker. In-vivo study revealed no any irritation and inflammation to the skin promoting drug delivery system to treat psoriasis.

CONCLUSION

In conclusion, Mometasone furoate loaded aspasomal gel releases the drug for longer duration of time and reduce dosing frequency, providing the new dimension for the treatment of psoriasis.

Cutaneous Application of Celecoxib for Inflammatory and Cancer Diseases

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) and particularly selective cyclooxygenase-2 (COX-2) inhibitors such as celecoxib (Cxb) are considered promising cancer chemopreventive for colon, breast, prostate, lung, and skin cancers. However, the clinical application to the prevention is limited by concerns about safety, potential to serious toxicity (mainly for healthy individuals), efficacy and optimal treatment regimen. Cxb exhibits advantages as potent antiinflammatory and gastrointestinal tolerance compared with conventional NSAID's. Recent researches suggest that dermatological formulations of Cxb are more suitable than oral administration in the treatment of cutaneous disease, including skin cancer. To date, optimism has been growing regarding the exploration of the topical application of Cxb (in the prevention of skin cancers and treatment of cutaneous inflammation) or transdermal route reducing risks of systemic side effects.

OBJECTIVE

This paper briefly summarizes our current knowledge of the development of the cutaneous formulations or delivery systems for Cxb as anti-inflammatory drug (for topical or transdermal application) as well its chemopreventive properties focused on skin cancer.

CONCLUSION

New perspectives emerge from the growing knowledge, bringing innovative techniques combining the action of Cxb with other substances or agents which act in a different way, but complementary, increasing the efficacy and minimizing toxicity.

The bactericidal effect of liposomal vancomycin as a topical combating system against Methicillin-resistant Staphylococcus aureus skin wound infection in mice

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common causes of skin infections and treatment is difficult due to its resistance to the most of antibiotics. Although vancomycin is often considered as an antibacterial agent of choice for the treatment of MRSA, its use is limited because of the high side effects. One solution is using liposomal formulation for local drug delivery. The aim of this study was to determine in vitro and in vivo efficacies of liposomal vancomycin as topical use.

Methods: To prepare liposomal vancomycin, the ammonium sulfate gradient using remote loading and freeze-thaw methods was applied. Then, synthesized nanoliposomes were evaluated in terms of particle size, morphology, stability, and encapsulation efficiency. Minimum inhibitory concentration (MIC) of synthesized nanoliposome against MRSA was detected. The cytotoxicity of synthesized nanoliposome was evaluated using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Finally, the topical antibacterial activity of each formulation was tested against MRSA-infected skin wound model in mice.

Results: High encapsulation efficiency was achieved for all synthesized nanoliposomes. The results of in vitro and in vivo showed that liposomal vancomycin was more effective than free vancomycin. Also, synthesized nanoliposome showed no cytotoxicity on human epidermoid cell line.

Conclusion: The results showed that synthesized nanoliposome could be applied as a great topical antimicrobial construct for treatment of MRSA skin infections.

Topical and Transdermal Drug Delivery: From Simple Potions to Smart Technologies

This overview on skin delivery considers the evolution of the principles of percutaneous ab-sorption and skin products from ancient times to today. Over the ages, it has been recognised that products may be applied to the skin for either local or systemic effects. As our understanding of the anatomy and physiology of the skin has improved, this has facilitated the development of technologies to effectively and quantitatively deliver solutes across this barrier to specific target sites in the skin and beyond. We focus on these technologies and their role in skin delivery today and in the future.

Eco-scalable baicalin loaded vesicles developed by combining phospholipid with ethanol, glycerol, and propylene glycol to enhance skin permeation and protection

A new class of biocompatible and scalable phospholipid vesicles was developed, aiming at improving the efficacy of baicalin on the skin. Phosphatidylcholine and baicalin (a natural polyphenol) were hydrated in two steps with a mixture of ethanol, glycerol, and propylene glycol at different ratios, and a low amount of water (4%). Hence, water was almost completely replaced by the co-solvents, which were never used before as predominant dispersing medium of phospholipid vesicles. The vesicles appeared three-dimensionally structured, forming a network that conferred a high viscosity to the dispersions. The vesicles were unilamellar, small in size (∼100 nm), and stable during 12 months of storage. They disclosed optimal performances in the transdermal delivery of baicalin, and high biocompatibility with skin cells (i.e., keratinocytes and fibroblasts). Furthermore, the vesicles promoted the efficacy of baicalin in protecting skin cells against oxidative stress in vitro and injured skin in vivo.

Nanosized nasal emulgel of resveratrol: preparation, optimization, in vitro evaluation and in vivo pharmacokinetic study

Nano-emulgel has become one of the most significant controlled release systems, which has the advantages of both gels and nano-emulsions. This work aims at the formulation of nasal nano-emulgel for resveratrol, employing carbopol 934 and poloxamer 407 as the gelling agents. The optimum nano-emulsion was determined through further characterization of the selected system. The nasal nano-emulgel was prepared and tested for the in vitro release, the release kinetics, FTIR, ex vivo permeation, nasal mucosa toxicity, and in vivo pharmacokinetic study. The optimum nano-emulsion consisted of Tween 20, Capryol 90, and Transcutol at a ratio of (54.26: 23.81: 21.93%v/v), and it exhibited transmittance of 100%, resveratrol solubility of 159.9 ± 6.4 mg/mL, globule size of 30.65 nm. The in vitro resveratrol released from nano-emulsion and nasal nano-emulgel was 96.17 ± 4.43% and 78.53 ± 4.7%, respectively. Ex vivo permeation was sustained during 12 h up to 63.95 ± 4.7%. The histopathological study demonstrated that the formula is safe and tolerable to the nasal mucosa. C_max and AUC _(0-∞) of resveratrol obtained after nasal administration of nasal nano-emulgel was 2.23 and 8.05 times, respectively. Similarly, T_max was increased up to 3.67 ± 0.82 h. The optimized nasal nano-emulgel established intranasal safety and bioavailability enhancement so it is considered as a well-designed system to target the brain.

Quality by design driven development of resveratrol loaded ethosomal hydrogel for improved dermatological benefits via enhanced skin permeation and retention

Resveratrol is a potent anti-oxidant agent and can be used for the effective management of different skin conditions like extrinsic skin ageing, psoriasis, etc. The objective of this research was to develop a dermal delivery system of resveratrol for its improved dermatological benefits for achieving its enhanced skin deposition profile with limited systemic exposure. Resveratrol loaded ethosomal hydrogel was developed and optimized using systematic Quality by Design approach. Firstly, the quality target product profile (QTPP) of ethosomal formulation was defined and critical quality attributes (CQAs) and critical material attributes (CMAs) were screened through risk assessment studies based on fish bone diagram. 3² full factorial design using Design Expert software was employed to optimize the selected CMAs. Concentration of phospholipid (X1) and concentration of ethanol (X2) were selected as independent CMAs. Vesicle size (Y1), entrapment efficiency (Y2), permeation flux (Y3) and drug deposition in dermal layer (Y4) were evaluated as dependant CQAs. Optimized formulation was then evaluated for physicochemical and skin permeation properties. Ethosomal hydrogel was able to significantly enhance the skin permeation parameters and skin deposition of resveratrol in comparison to the conventional cream. The results were highly ratified by CLSM studies in which ethosomal hydrogel was found to be vastly scattered in the deeper skin layers. Thus, there is evidence that systemically developed ethosomal gel can deliver enhanced amounts of bioactives into the skin and it is expected that a number of products for dermal/transdermal applications will be developed in the future based on it.

Nanosized Transferosome-Based Intranasal In Situ Gel for Brain Targeting of Resveratrol: Formulation, Optimization, In Vitro Evaluation, and In Vivo Pharmacokinetic Study

Resveratrol (RES) is a potent antioxidant used for the management of several central nervous system diseases. RES bioavailability is less than 1 owing to its low solubility and extensive intestinal and hepatic metabolism. The aim of the study was to enhance RES bioavailability through developing intranasal transferosomal mucoadhesive gel. Reverse evaporation-vortexing sonication method was employed to prepare RES-loaded transferosomes. Transferosomes were developed via 3⁴ definitive screening design, using soya lecithin, permeation enhancers, and surfactants. The optimized formula displayed spherical shape with vesicle size of 83.79 ± 2.54 nm and entrapment efficiency (EE%) of 72.58 ± 4.51%. Mucoadhesive gels were prepared and evaluated, then optimized RES transferosomes were incorporated into the selected gel and characterized using FTIR spectroscopy, in vitro release, and ex vivo permeation study. Histopathological examination of nasal mucosa and in vivo pharmacokinetic study were conducted. In vitro drug release from transferosomal gel was 65.87 ± 2.12% and ex vivo permeation was 75.95 ± 3.19%. Histopathological study confirmed the safety of the optimized formula. The C_max of RES in the optimized RES trans-gel was 2.15 times higher than the oral RES suspension and AUC_(0-∞) increased by 22.5 times. The optimized RES trans-gel developed intranasal safety and bioavailability enhancement through passing hepatic and intestinal metabolism.

Mangiferin nanoemulsions in treatment of inflammatory disorders and skin regeneration

In this paper mangiferin nanoemulsions were developed using hyaluronic acid of different molecular weight, in absence or presence of Transcutol-P. An extensive study was carried out on the physico-chemical properties of nanoemulsions. Nanosizer and transmission electron microscopy showed oil droplets average size 296 nm with monodisperses distribution (PI ≤ 0.30). The zeta potential was highly negative (-30 mV). FTIR analysis confirms the existence of physical interactions among compounds. Rheological measurements allowed to conclude that all formulations present a pseudoplastic behavior (s ∼ 0.4) in presence of the biopolymer. Moreover, mangiferin release depends on the molecular weight of the polymer. Permeability assays on pig epidermis showed that nanoemulsions with low molecular weight hyaluronic acid improve the permeation, being this effect more pronounced in nanoemulsions with Transcutol-P. Administration of mangiferin nanoemulsions on TPA-inflamed skin mice model provided an attenuation of oedema and leucocyte infiltration. Macroscopic appearance of mice skin lesions has a good correlation with the histological study. The topical application of these formulations shows an appropriate anti-inflammatory effect.

Preparation and optimization of monodisperse polymeric microparticles using modified vibrating orifice aerosol generator for controlled delivery of letrozole in breast cancer therapy

Letrozole (LTZ) is effective for the treatment of hormone-receptor-positive breast cancer in postmenopausal women. In this work, and for the first time, using vibrating orifice aerosol generator (VOAG) technology, monodisperse poly-ε-caprolactone (PCL), and poly (D, L-Lactide) (PDLLA) LTZ-loaded microparticles were prepared and found to elicit selective high cytotoxicity against cancerous breast cells with no apparent toxicity on healthy cells in vitro. Plackett-Burman experimental design was utilized to identify the most significant factors affecting particle size distribution to optimize the prepared particles. The generated microparticles were characterized in terms of microscopic morphology, size, zeta potential, drug entrapment efficiency, and release profile over one-month period. Long-term cytotoxicity of the microparticles was also investigated using MCF-7 human breast cancer cell lines in comparison with primary mammary epithelial cells (MEC). The prepared polymeric particles were monodispersed, spherical, and apparently smooth, regardless of the polymer used or the loaded LTZ concentration. Particle size varied from 15.6 to 91.6 µm and from 22.7 to 99.6 µm with size distribution (expressed as span values) ranging from 0.22 to 1.24 and from 0.29 to 1.48 for PCL and PDLLA based microparticles, respectively. Upon optimizing the manufacture parameters, span was reduced to 0.162-0.195. Drug entrapment reached as high as 96.8%, and drug release from PDLLA and PCL followed a biphasic zero-order release using 5 or 30% w/w drug loading in the formulations. Long-term in vitro cytotoxicity studies indicated that microparticles formulations significantly inhibited the growth of MCF-7 cell line over a prolonged period of time but did not have toxic effects on the normal breast epithelial cells.

Gel in core carbosomes as novel ophthalmic vehicles with enhanced corneal permeation and residence

Carbopol is a good bio-adhesive polymer that increases the residence time in the eye. However, the effect of blinking and lacrimation still reduce the amount of polymer and the incorporated drug available for bioadhesion. Gel-core liposomes are advanced systems offering benefits making it a good tool for improved ocular drug delivery and residence time. Incorporation of carbopol in gel-core liposomes and their potential in ocular delivery have not so far been investigated. Fluconazole (FLZ) was selected as a challenging important ocular antifungal suffering from poor corneal permeation and short residence time. In this study, gel-core carbosomes have been elaborated as novel carbopol-based ophthalmic vehicles to solve ocular delivery obstacles of FLZ and to sustain its effect. Full in vitro appraisal was performed considering gel-core structure, entrapment efficiency, particle size and stability of the vesicles as quality attributes. Structure elucidation of the nanocarrier was performed using optical, polarizing and transmission electron microscopy before and after Triton-X100 addition. Ex-vivo ocular permeation and in vivo performance were investigated on male albino rabbits. Optimized formulation (CBS5) showed gel-core structure, nanosize (339.00 ± 5.50 nm) and not defined before (62.00% ± 1.73) entrapment efficiency. Cumulative amount of CBS5 permeated ex-vivo after 6 h, was 2.43 and 3.43 folds higher than that of conventional liposomes and FLZ suspension, respectively. In-vivo corneal permeation of CBS5 showed significantly higher AUC0-24 h (487.12 ± 74.80) compared to that of FLZ suspension (204.34 ± 7.46) with longer residence time in the eye lasts for more than 18 h. In conclusion, novel gel-core carbosomes could successfully be used as a promising delivery system for chronic ocular diseases.

Potential enhancement and targeting strategies of polymeric and lipid-based nanocarriers in dermal drug delivery

Nanocarriers used for alternative drug-delivery strategies have gained interest due to improved penetration and delivery of drugs into specific regions of the skin in recent years. Dermal drug delivery via polymeric-based nanocarriers (polymeric nanoparticles, micelles, dendrimers) and lipid-based nanocarriers (solid–lipid nanoparticles and nanostructured lipid carriers, vesicular nanocarriers including liposomes, niosomes, transfersomes and ethosomes) has been widely investigated. Although penetration of nanocarriers through the intact skin could be restricted, these carriers are particularly considered as feasible for the treatment of dermatological diseases in which the skin barrier is disrupted and also for follicular delivery of drugs for management of skin disorders such as acne. This review mainly highlights the recent approaches on potential penetration enhancement and targeting mechanisms of these nanocarriers.

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.

Application of Quality by Design: Development to Manufacturing of Diclofenac Sodium Topical Gel

The objective of the present study was to develop and optimize generic topical gel formulation of diclofenac sodium through quality by design approaches. The quality target product profile was set for the critical quality attributes of the gel. The key material variables like hydrophilic gelling agent carbopol and penetration enhancer kolliphor were optimized using design of experiments. A central composite design was used considering viscosity and cumulative percent diffusion of the drug after 0.5, 1, 2, 4 and 6 h as responses. The p values for all models generated for different responses were statistically significant (<0.5). Design space was established and verified at the laboratory scale. The predicted and observed values were in close agreement. The robustness of the formula was tested at a higher scale (10X and 200X). The capability index was calculated followed by Monte Carlo simulation and the Cpk values for all the responses were more than 1.33.

Topical Nano and Microemulsions for Skin Delivery

Nanosystems such as microemulsions (ME) and nanoemulsions (NE) offer considerable opportunities for targeted drug delivery to and via the skin. ME and NE are stable colloidal systems composed of oil and water, stabilised by a mixture of surfactants and cosurfactants, that have received particular interest as topical skin delivery systems. There is considerable scope to manipulate the formulation components and characteristics to achieve optimal bioavailability and minimal skin irritancy. This includes the incorporation of established chemical penetration enhancers to fluidize the stratum corneum lipid bilayers, thus reducing the primary skin barrier and increasing permeation. This review discusses nanosystems with utility in skin delivery and focuses on the composition and characterization of ME and NE for topical and transdermal delivery. The mechanism of skin delivery across the stratum corneum and via hair follicles is reviewed with particular focus on the influence of formulation.

Intranasally administered in situ gelling nanocomposite system of dimenhydrinate: preparation, characterization and pharmacodynamic applicability in chemotherapy induced emesis model

The aim of the current manuscript was to test the applicability of a nanocomposite system of penetration enhancer vesicles (PEVs) within polymeric in situ forming gel network composed of poloxamer and hyaluronic acid for the intranasal delivery of the antiemetic dimenhydrinate (DMH). PEVs were prepared using phospholipids and labrasol/transcutol/PEG 400 as penetration enhancers, and characterized for entrapment efficiency (EE%), particle size, zeta potential and morphology. The nanocomposite in situ forming gel system was characterized for its sol-gel temperature, viscosity and mucoadhesiveness, and was pharmacodynamically tested on a cisplatin induced emesis model in rats in terms of food, water, kaolin intake and stomach weight content. The selected PEVs formula displayed EE% of 83% for DMH, particle size of 121 nm and a surface charge of 0.83 mV. The selected nanocomposite in situ gelling formula showed a viscosity of 2.13 Pa.S, mucoadhesive force of 0.62 N and DMH controlled release over 6 hours. The pharmacodynamic study showed the superiority of the nanocomposite in situ gelling formula; being administered at a lower dose than the oral marketed formula. The described nanocomposite system proved to be successful for the intranasal delivery of DMH, thus presenting a promising delivery modality for similar antiemetics.

Alkylglycerol Derivatives, a New Class of Skin Penetration Modulators

The absorption modulating activity of two alkylglycerol derivatives (batyl and chimyl alcohol) on skin barrier properties was evaluated. Biophysical tests such as transepidermal water loss (TEWL) and attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy, as well as in vitro skin permeation studies, were performed in order to determine the effect of these compounds as chemical absorption modulators. Four drugs were used as models: three NSAIDS (diclofenac, naproxen, and piroxicam) and glycyrrhizic acid. The results showed that treatment of the skin with alkylglycerols caused (i) a reduction on the amount of drug permeated; (ii) a reduction in TEWL; and (iii) changes in the ATR-FTIR peaks of stratum corneum lipids, indicative of a more ordered structure. All of these findings confirm that alkyl glycerols have an absorption retarding effect on the drugs tested. Such effects are expected to give rise to important applications in the pharmaceutical and cosmetic sectors, in cases where it is desirable for the drug to remain in the superficial layers of the skin to achieve a local effect.