Elastic Liposomal Formulation for Sustained Delivery of Antimigraine Drug: In Vitro Characterization and Biological Evaluation

Application of high-polarity hydroxyl polyacrylate pressure sensitive adhesive in rizatriptan transdermal drug delivery patch

This study aimed to design a rizatriptan (RIZ) transdermal patch by combining of high-polarity hydroxyl pressure sensitive adhesive (PSA) AAOH-45 with an ion-pair strategy and investigate the molecular mechanism of high content hydroxyl PSA to enhance drug-PSA miscibility. RIZ free base, ion-pair complexes and PSAs containing hydroxyl group were prepared and characterized. Formulation factors including counter-ions, PSAs, drug-loading and others were optimized through single-factor studies and evaluated through pharmacokinetic studies and skin irritation tests. The properties of high polarity PSA and molecular mechanism of drug-PSA miscibility were investigated through molecular simulation, FTIR spectra, 13C NMR spectra, DSC, and rheology study. The optimized formulation contained 20 % (w/w) RIZ-OA (Rizatriptan-Oleic acid), 80 % AAOH-45 (w/w) as the matrix, and had a thickness of 90 μm. Compared with the oral group (MRT0-t = 5.96 ± 0.97 h) and the control patch group (MRT0-t = 11.30 ± 1.78 h), the pharmacokinetic behavior of the optimization group demonstrated sustained drug delivery behavior (MRT0-t = 20.21 ± 0.61 h) with no irritation phenomenon. The miscibility of RIZ with PSAs was positively correlated with the mass percentage of 2-HEA. Higher polar similarity, lower flowability, and stronger intermolecular interaction were responsible for the higher compatibility of high hydroxyl PSA with the drug. This study provided a reference for increasing the drug-loading in PSA and developing RIZ patch.

Application and Efficacy of Melatonin Elastic Liposomes in Photoaging Mice

Transdermal drug delivery system is a preferable choice to overcome the low bioavailability of oral medication. Elastic liposomes have shown great effectiveness for percutaneous transport of melatonin (MLT). In this study, the elastic liposomes loaded with MLT were prepared using thin-film dispersion method and optimized through the central composite design (CCD) approach. The physicochemical properties and skin permeation against UV-induced skin photoaging efficacy of the developed MLT-ELs were assessed. The average size of the MLT-ELs was about 49 nm with a spherical shape and high encapsulation efficiency (73.91%) and drug loading (9.92%). The results of FTIR, DSC, and XRD revealed that the chemical structure of MLT was not changed after prepared elastic liposomes, and the drug was successfully encapsulated in the elastic liposome membrane material. In vitro skin permeation evaluation showed that the cumulative penetration of elastic liposomes was 1.5 times higher than that of conventional liposomes, highlighting that the elastic liposomes more easily penetrated into the body. The photoaging experiment results indicated that topical MLT-EL treatment ameliorated the skin elasticity, enhanced the skin hydration level, and preserved the integrity of dermal collagen and elastic fibers. It could be concluded that the elastic liposomes might serve as a promising platform for the transdermal delivery of melatonin.

Allopurinol Loaded Transferosomes for the Alleviation of Symptomatic After-effects of Gout: An Account of Pharmaceutical Implications

Background:

The present study assessed the transdermal potential of transferosomes loaded with allopurinol for the treatment of gout.

Methods:

Transferosomes of allopurinol were composed of different ratios of tween-80, soya lecithin and solvent using a thin-film hydration method. Transferosomes were characterized for Scanning Electron Microscopy (SEM), zeta potential, % entrapment efficiency (%EE), Fourier Transform Infrared Spectroscopy (FTIR), in-vitro drug release and kinetics as well as stability. Then, optimized formulation was incorporated in gel and evaluated for viscosity, pH, extrudability, homogeneity, skin irritation study, spreadability, ex vivo skin permeation study, flux, and stability.

Results:

SEM studies suggested that vesicles were spherical and zeta potential were in the range of -11.4 mV to -29.6 mV and %EE was 52.4- 83.87%. FTIR study revealed that there was no interaction between allopurinol and excipients during the preparation of transferosomes. The cumulative percentage of drug release from various transferosomes was ranged from 51.87 to 81.87%. A transferosomal gel of F8 formulation was prepared using dispersion method reported pseudoplastic rheological behavior, optimum pH, spreadability and maximum drug permeation i.e. 79.84% with flux 13.06 g/cm2/hr, followed zero-order release kinetics. Irritation and in-vivo studies of optimized transferosomal gel G8 on rabbits revealed better results than the standard allopurinol.

Conclusion:

This research suggested that allopurinol loaded transferosomal gel can be potentially used as a transdermal drug delivery system for the treatment of gout.

Elastic liposomes as novel carriers: recent advances in drug delivery

Elastic liposomes (EL) are some of the most versatile deformable vesicular carriers that comprise physiologically biocompatible lipids and surfactants for the delivery of numerous challenging molecules and have marked advantages over other colloidal systems. They have been investigated for a wide range of applications in pharmaceutical technology through topical, transdermal, nasal, and oral routes for efficient and effective drug delivery. Increased drug encapsulation efficiency, enhanced drug permeation and penetration into or across the skin, and ultradeformability have led to widespread interest in ELs to modulate drug release, permeation, and drug action more efficiently than conventional drug-release vehicles. This review provides insights into the versatile role that ELs play in the delivery of numerous drugs and biomolecules by improving drug release, permeation, and penetration across the skin as well as stability. Furthermore, it provides future directions that should ensure the widespread use of ELs across all medical fields.

Ethogel topical formulation for increasing the local bioavailability of 5-fluorouracil: a mechanistic study

5-Fluorouracil (5-FU) is an anticancer drug and is considered a gold standard for the treatment of skin cancer. At present, topical chemotherapy with 5-FU is associated with the limitations of poor skin permeation, retention at target site, and skin irritation potential. In the present study, an attempt has been made to develop an ethosome-based topical gel formulation (ethogel) for skin targeting of 5-FU. The ethosomal formulation was prepared using the classical dispersion method, and loading of 5% w/w of the drug was optimized to the commercial strength of marketed 5-FU cream. Carbopol 934P was used as a gel former in 0.5, 0.75, 1.0, and 1.5% w/w concentration for preparation of ethosome-based ethogel formulation. The ethogel formulation was characterized for viscosity, spreadability, extrudability, and pH. Viscosity of the developed ethogel and that of the marketed formulation was found to be 3070±14.7 and 2870±14.4 cP, respectively. An in-vitro skin permeation and deposition study was carried out across rat skin using the marketed cream and 5-FU drug solution as controls. The amount of drug deposition was found to increase 5.9- and 9.4-fold on treatment with ethogel in comparison with the marketed cream and drug solution, respectively. The result of antitumor activity evaluated using a Cytoselect 96-well cell transformation assay revealed a large reduction in tumor density with treatment with the 5-FU ethogel formulation in comparison with the marketed formulation. A significant reduction in the skin irritation potential of 5-FU ethogel formulation was also found in comparison with that of the marketed formulation as measured by the Draize test. The results of the present study demonstrated ethogel as a better alternative for increasing the local bioavailability of 5-FU in comparison to the marketed formulation.

Transfersomes: a novel vesicular carrier for enhanced transdermal delivery of sertraline: development, characterization, and performance evaluation

The aim of the present study was to investigate transfersomes as a transdermal delivery system for the poorly soluble drug, sertraline, in order to overcome the troubles associated with its oral delivery. Different transfersomal formulations were prepared with non-ionic surfactant (span 80), soya lecithin, and carbopol 940 by the rotary evaporation sonication method. The prepared formulations were characterized for light microscopy, particle size analysis, drug entrapment, turbidity, drug content, rheological studies, in vitro release, ex vivo permeation, and stability studies. The optimized formulation was evaluated for in vivo studies using the modified forced swim model test. FTIR studies showed compatibility of the drug with excipients. The result revealed that sertraline in all of the formulations was successfully entrapped with uniform drug content. Transfersomal gel containing 1.6% of the drug and 20% of span 80 was concluded to be the optimized formulation (EL-SP4), as it showed maximum drug entrapment (90.4±0.15%) and cumulative percent drug release(73.8%). The ex vivo permeation profile of EL-SP4 was compared with the transfersomal suspension, control gel, and drug solution. The transfersomal gel showed a significantly higher (p<0.05) cumulative amount of drug permeation and flux along with lower lag time than the drug solution and drug gel. It also owed to better applicability due to the higher viscosity imparted by the gel rather than the transfersomal suspension, and no skin irritation was observed. The modified forced swim test in mice revealed that the transfersomal gel had better antidepressant activity as compared to the control gel. Thus, the study substantiated that the transfersomal gel can be used as a feasible alternative to the conventional formulations of sertraline with advanced permeation characteristics for transdermal application.

Development of a liposome microbicide formulation for vaginal delivery of octylglycerol for HIV prevention

The feasibility of using a liposome drug delivery system to formulate octylglycerol (OG) as a vaginal microbicide product was explored. A liposome formulation was developed containing 1% OG and phosphatidyl choline in a ratio that demonstrated in vitro activity against Neisseria gonorrhoeae, HSV-1, HSV-2 and HIV-1 while sparing the innate vaginal flora, Lactobacillus. Two conventional gel formulations were prepared for comparison. The OG liposome formulation with the appropriate OG/lipid ratio and dosing level had greater efficacy than either conventional gel formulation and maintained this efficacy for at least 2 months. No toxicity was observed for the liposome formulation in ex vivo testing in a human ectocervical tissue model or in vivo testing in the macaque safety model. Furthermore, minimal toxicity was observed to lactobacilli in vitro or in vivo safety testing. The OG liposome formulation offers a promising microbicide product with efficacy against HSV, HIV and N. gonorrhoeae.

Effect of iontophoresis on in vitro transdermal absorption of almotriptan

The aim of the present work was to characterize the in vitro transdermal absorption of almotriptan through pig ear skin. The passive diffusion of almotriptan malate and its iontophoretic transport were investigated using current densities of 0.25 and 0.50mA/cm(2). In vitro iontophoresis experiments were conducted on diffusion cells with an agar bridge without background electrolytes in the donor compartment. Although both current densities applied produced a statistically significant increment with respect to passive permeation of almotriptan (p<0.01), that of 0.50mA/cm(2) proved to be the best experimental condition for increasing the transport of almotriptan across the skin. Under these experimental conditions, the transdermal flux of the drug increased 411-fold with respect to passive diffusion, reaching 264±24μg/cm(2)h (mean±SD). Based on these results, and taking into account the pharmacokinetics of almotriptan, therapeutic drug plasma levels for the management of migraine could be achieved via transdermal iontophoresis using a reasonably sized (around 7.2cm(2)) patch.

Retinyl palmitate flexible polymeric nanocapsules: characterization and permeation studies

Polymeric nanocapsules with elastic characteristics were prepared by the pre-formed polymer interfacial deposition method. The system consists of an oily core of retinyl palmitate with Span 60 and a polymeric wall of poly(D,L-lactide) (PLA). A narrow size distribution (215 nm, P.D.I. 0.10) was showed by dynamic light scattering (DLS) analyses. Particle deformability was observed by transmission electron microscopy (TEM) images and permeation of the particles through two superposed membranes of smaller pore diameters. Permeation studies were achieved using plastic surgery abdominal human skin by Franz diffusion cell. Retinyl palmitate permeates into deep skin layers. Besides, a PLA fluorescent derivative conjugated with Nile blue dye by an amide covalent bound was additionally obtained. Permeation profile of the nanocapsules with the fluorescent polymer was evaluated by confocal laser scanning microscopy (CLSM). The CLSM showed that nanocapsules were distributed uniformly, suggesting that the permeation mechanism through skin is intercellular. Thus, the use of these nanocapsules may be a feasible strategy to enhance the permeation of actives into the skin when delivery to deep layers is aimed.

Drug-cyclodextrin-vesicles dual carrier approach for skin targeting of anti-acne agent

In the present study attempt was made for preparation of isotretinoin-hydroxypropyl beta cyclodextrin (HP-beta-CD) inclusion complex and encapsulate this complex in elastic liposomes to study the effect of dual carrier approach on skin targeting of isotretinoin. The isotretinoin HP-beta-CD complex was prepared by freeze-drying method and characterized by IR spectroscopy. The drug and drug-CD complex loaded elastic liposomal formulation were prepared and characterized in vitro, ex-vivo and in vivo for shape, size, entrapment efficiency, no. of vesicles per cubic mm, in vitro skin permeation and deposition study, photodegradation and skin toxicity assay. The transdermal flux for different vesicular formulations was observed between 10.5 +/- 0.5 to 13.9 +/- 1.6 microg/cm(2)/h. This is about 15-21 folds higher than that obtained from drug solution (0.7 +/- 0.1 microg/cm(2)/h) and 4-5 folds higher than obtained with drug-CD complex solution (2.7 +/- 0.1 microg/cm(2)/h). The amount of drug deposit was found to increase significantly (p < 0.05) by cyclodextrin complexation (30.1 +/- 0.1 microg). The encapsulation of this complex in elastic liposomal formulation further increases its skin deposition (262.2 +/- 21 microg). The results of skin irritation study using Draize test also showed the significant reduction in skin irritation potential of isotretinoin elastic liposomal formulation in comparison to free drug. The results of the present study demonstrated that isotretinoin elastic liposomal formulation possesses great potential for skin targeting, prolonging drug release, reduction of photodegradation, reducing skin irritation and improving topical delivery of isotretinoin.

Transdermal delivery of sumatriptan for the treatment of acute migraine

SUMMARY

Migraine is a common, multisymptom disorder that can severely impact the daily activities of migraineurs. Triptans (primarily sumatriptan) are the most commonly prescribed treatment for migraine and are considered a relatively safe and effective initial therapy. Unfortunately, current sumatriptan formulations (i.e., oral, nasal, subcutaneous) may be associated with limitations that can result in patients' delaying or avoiding treatment. For oral formulations, these limitations include difficulty in taking an oral medication due to the nausea and vomiting that often accompany migraine, and inconsistent absorption, whereas nasal and subcutaneous formulations may be associated with low bioavailability and an undesirable rate of adverse events, respectively. An alternative to current formulations is transdermal drug delivery, particularly iontophoresis. Transdermal delivery has several advantages over current formulations, including avoidance of the gastrointestinal tract, controlled and sustained delivery, and convenient administration. This article reviews the in vitro, in vivo, and preclinical data supporting the use of iontophoresis for the delivery of sumatriptan, as well as the recent clinical data for Zelrix (NuPathe Inc., Conshohocken, PA), an iontophoretic sumatriptan patch currently in phase III development for the treatment of migraine.

Elastic liposomal formulation for sustained delivery of colchicine: in vitro characterization and in vivo evaluation of anti-gout activity

Colchicine, an alkaloid found in extracts of the plants Colchicum autumnale and Gloriosa superb, is effective in the treatment of acute gout and dermatological conditions like leuko-cytoclastic vasculitis, psoriasis, and Sweet's syndrome. Oral administration of colchicine is associated with gastrointestinal side effects and its accumulation in the body leads to bone marrow suppression. In the present study, an attempt has been made for development and in vitro and in vivo evaluation of elastic liposomal formulation for topical delivery of colchicine. The in vitro skin permeation study across rat skin found transdermal flux for different elastic liposomal formulations to range between 32.8 +/- 1.2 and 44.4 +/- 1.9 microg h(-1) cm(-2), which was approximately seven to 11 times higher than obtained using drug solution (4.3 +/- 0.6 microg h(-1) cm(-2)). The results of skin deposition study showed that elastic liposomal formulation provide 12.5-fold higher skin deposition as compared to drug solution of colchicine. Confocal laser scanning microscopy also revealed better accumulation and deeper penetration (up to 200 microm) of elastic liposomes than drug solution (up to 12 microm). The biological evaluation of various vesicular formulations and drug solution was carried out using monosodium urate-induced air pouch model. The results of anti-gout activity in rats showed better and sustained biological effects in 24 h measured in terms of exudate volume (63.1 +/- 5.7% and 9.6 +/- 0.5% reduction with elastic liposomes and drug solution, respectively), reduction in leukocyte count (74.2 +/- 6.0% and 4.1 +/- 0.3% reduction with elastic liposomes and drug solution, respectively), decrease in inflammatory cells accumulation, and collagen deposition with elastic liposomal formulation than drug solution. Hence, the present study reveals that elastic liposomal formulation of colchicine possesses greater potential to enhance skin accumulation, prolong drug release, and improve the site-specificity of colchicine.