Transdermal delivery of heparin using pulsed current iontophoresis

Transcutaneous Delivery of Dexamethasone Sodium Phosphate Via Microneedle-Assisted Iontophoretic Enhancement - A Potential Therapeutic Option for Inflammatory Disorders

AIM

This study aimed to fabricate dexamethasone sodium phosphate loaded microneedle arrays (MNA) and investigate their efficiency in combination with iontophoresis for the treatment of hind paw oedema in rats.

METHODS

Drug loaded polyvinyl alcohol, polyvinyl pyrrolidone and D-sorbitol-based MNA11 were fabricated by vacuum micromolding. Physicochemical, morphological, thermal, in-silico, in-vitro insertion ability (on parafilm) and drug release studies were performed. Ex-vivo permeation, in-vivo insertion and anti-inflammatory studies were performed in combination with iontophoresis.

RESULTS

MNA11 displayed sharp-tipped projections and acceptable physicochemical features. Differential scanning calorimetry results indicated that drug loaded MNA11 were amorphous solids. Drug interacted with PVP and PVA predominately via hydrogen bonding. Parafilm displayed conspicuously engraved complementary structure of MNA11. Within 60 min, 91.50 ± 3.1% drug released from MNA11. A significantly higher i.e., 95.06 ± 2.5% permeation of drug was observed rapidly (within 60 min) from MNA11-iontophoresis combination than MNA11 i.e., 84.07 ± 3.5% within 240 min. Rat skin treated using MNA11 and MNA11-iontophoresis showed disruptions / microchannels in the epidermis without any damage to underlying anatomical structures. MNA11-iontophoresis combination led to significant reduction (83.02 ± 3.9%) in paw oedema as compared to MNA11 alone (72.55 ± 4.1%).

CONCLUSION

MNA11-iontophoresis combination can act as a promising candidate to deliver drugs transcutaneously for treating inflammatory diseases.

Improved Transdermal Delivery of Rabies Vaccine using Iontophoresis Coupled Microneedle Approach

AIM

This study was aimed to develop rabies vaccine incorporated microneedle (MN) patches and evaluate the immunogenicity of prepared formulations in combination with iontophoresis.

METHODS

Patches comprising of polyvinyl pyrrolidone, hyaluronic acid and polyethylene glycol 400 were engineered by vacuum micromolding technique. Physical evaluation of patches included determination of folding endurance, % swelling and morphological features. In vitro release study was performed in skin simulant agarose gel using model drug (methylene blue) loaded patches. In vitro insertion ability was assessed using stratum corneum simulant parafilm. In vivo insertion study was performed in rats. Immunogenicity was evaluated in dogs by determining immunoglobulin G (IgG) and rabies virus neutralizing antibodies (RVNA) titer.

RESULTS

Patches displayed uniformly distributed microprojections with pointed tips and smooth surface,  ~ 70% swelling, remained intact for  ~ 200 foldings and successfully penetrated the parafilm. The area covered by model drug across agarose gel was almost double following treatment with MN-iontophoresis combination (MNdi) compared to MN alone (MNdo). Histological examination of rat skin treated with vaccine laden MN (MNvo) and MN-iontophoresis combination (MNvi) confirmed the formation of grooves in epidermis without any damage to the deep vasculature. A ~ 73% and  ~ 206% increase (compared to untreated counterpart) was observed in the IgG titer of MNvo and MNvi treated dogs, respectively. The RVNA titer was increased by  ~ 1.2 and  ~ 2.2 times (compared to threshold value) after MNvo and MNvi treatment, respectively.

CONCLUSION

MN-iontophoresis combination provided relatively potent immunogenic response over the conventional intramuscular injection, hence, can be used for administering vaccines transcutaneously.

Effects of electrical stimulation on skin surface

ABSTRACT

Skin is the largest organ in the body, and directly contact with the external environment. Articles on the role of micro-current and skin have emerged in recent years. The function of micro-current is various, including introducing various drugs into the skin locally or throughout the body, stimulating skin wounds healing through various currents, suppressing pain caused by various diseases, and promoting blood circulation for postoperative muscle rehabilitation, etc. This article reviews these efforts. Compared with various physical and chemical medical therapies, micro-current stimulation provides a relatively safe, non-invasive therapy with few side effects, giving modern medicine a more suitable treatment option. At the same time, the cost of the electrical stimulation generating device is relatively low, which makes it have wider space to and more clinical application value. The current micro-current stimulation technology has become more and more mature, but there are still many problems in its research. The design of the experiment and the selection of the current parameters not standardized and rigorous. Now, clear regulations are needed to regulate this field. Micro-current skin therapy has become a robust, reliable, and well-structured system.

Rehabilitation Interventions in the Multidisciplinary Management of Patients With Sclerotic Graft-Versus-Host Disease of the Skin and Fascia

Graft-versus-host disease (GVHD) is a multisystemic disorder that affects 30%-80% of patients who undergo allogeneic hematopoietic stem cell transplantation 10%-15% of GVHD patients develop sclerotic features affecting the skin or deeper tissues, leading to functional limitations and poor quality of life. There is limited literature regarding the indications and efficacy of specific rehabilitative interventions in sclerotic GVHD (sclGVHD). In this article, we summarize the current evidence supporting rehabilitation intervention in sclGVHD and offer our approach to the multidisciplinary management of this disease. In addition, we review techniques that have been employed in other sclerotic skin diseases (eg, iontophoresis, extracorporeal shock waves, botulinum toxin A, adipose derived stromal vascular fraction), but that require further validation in the sclGVHD setting. Ultimately, optimal care for this complex disease requires a multidisciplinary approach that includes a rehabilitation and adaptive program tailored to each patient's needs.

Laser-engineered dissolving microneedles for active transdermal delivery of nadroparin calcium

There is an urgent need to replace the injection currently used for low molecular weight heparin (LMWH) multidose therapy with a non- or minimally invasive delivery approach. In this study, laser-engineered dissolving microneedle (DMN) arrays fabricated from aqueous blends of 15% w/w poly(methylvinylether-co-maleic anhydride) were used for the first time in active transdermal delivery of the LMWH nadroparin calcium (NC). Importantly, an array loading of 630IU of NC was achieved without compromising the array mechanical strength or drug bioactivity. Application of NC-DMNs to dermatomed human skin (DHS) using the single-step 'poke and release' approach allowed permeation of approximately 10.6% of the total NC load over a 48-h study period. The cumulative amount of NC that permeated DHS at 24h and 48h attained 12.28±4.23IU/cm(2) and 164.84±8.47IU/cm(2), respectively. Skin permeation of NC could be modulated by controlling the DMN array variables, such as MN length and array density as well as application force to meet various clinical requirements including adjustment for body mass and renal function. NC-loaded DMN offers great potential as a relatively low-cost functional delivery system for enhanced transdermal delivery of LMWH and other macromolecules.

Novel sulfated polysaccharides disrupt cathelicidins, inhibit RAGE and reduce cutaneous inflammation in a mouse model of rosacea

BACKGROUND

Rosacea is a common disfiguring skin disease of primarily Caucasians characterized by central erythema of the face, with telangiectatic blood vessels, papules and pustules, and can produce skin thickening, especially on the nose of men, creating rhinophyma. Rosacea can also produce dry, itchy eyes with irritation of the lids, keratitis and corneal scarring. The cause of rosacea has been proposed as over-production of the cationic cathelicidin peptide LL-37.

METHODOLOGY/PRINCIPAL FINDINGS

We tested a new class of non-anticoagulant sulfated anionic polysaccharides, semi-synthetic glycosaminoglycan ethers (SAGEs) on key elements of the pathogenic pathway leading to rosacea. SAGEs were anti-inflammatory at ng/ml, including inhibition of polymorphonuclear leukocyte (PMN) proteases, P-selectin, and interaction of the receptor for advanced glycation end-products (RAGE) with four representative ligands. SAGEs bound LL-37 and inhibited interleukin-8 production induced by LL-37 in cultured human keratinocytes. When mixed with LL-37 before injection, SAGEs prevented the erythema and PMN infiltration produced by direct intradermal injection of LL-37 into mouse skin. Topical application of a 1% (w/w) SAGE emollient to overlying injected skin also reduced erythema and PMN infiltration from intradermal LL-37.

CONCLUSIONS

Anionic polysaccharides, exemplified by SAGEs, offer potential as novel mechanism-based therapies for rosacea and by extension other LL-37-mediated and RAGE-ligand driven skin diseases.

Topical heparin: new observations

Topical effects of heparins on the skin need deeper investigations. The lack of evidence is mainly due to the lack of large investments in this field. Three main local actions of heparin on the skin can be defined: (a) the anticoagulant action, (b) the microcirculatory-modulatory action determining important control of the microcirculation in case of excessive vasoconstriction or vasodilatation, and (c) the 'facilitatory action' on skin permeability allowing other drugs to diffuse better and faster into the skin (producing a therapeutic effect). These aspects have to be evaluated more extensively in both experimental and clinical conditions. Recent experimental studies demonstrate these effects of locally applied heparin. Therefore, key questions on local heparin administration such as skin penetration and the action on the local thrombi have promising answers. These observations suggest important clinical applications for local liposomal heparin. Both the potentials of local applications of heparin, particularly with new formulations, and some new aspects in the management of superficial vein thrombosis (SVT) can focus on locally applied heparin. SVT is an important clinical condition considering its frequency and the potentially heavy use of local heparin in this clinical problem. Results from new studies and observations presented in this issue of Angiology could be a window for suggesting new significant clinical applications and therapeutic solutions.

Transdermal delivery of interferon alpha-2B using microporation and iontophoresis in hairless rats

PURPOSE

To demonstrate transdermal delivery of interferon alpha-2b (IFNalpha2b) in hairless rats through aqueous microchannels (micropores) created in the skin and enhanced by iontophoresis.

MATERIALS AND METHODS

The Altea Therapeutics PassPort System was configured to form an array of micropores (2.0 cm(2); 72 micropores/cm(2)) on the rat abdomen. The transdermal patch (Iomed TransQ1-GS-hydrogel) was saturated with an IFNalpha2b solution (600 microg/ml) and applied for 4 h. Delivery was evaluated with and without cathodic iontophoresis (0.1 mA/cm(2)). Intravenous delivery (0.4 microg/100 g body weight) was performed to support pharmacokinetic calculations.

RESULTS

IFNalpha2b was not delivered through intact skin by itself (passive delivery) or during iontophoresis. However, passive delivery through micropores was achieved in vivo in rats. A dose of 397 +/- 67 ng was delivered over 6 h, with steady state serum concentrations reaching a plateau at 1 h post-patch application. These levels dropped rapidly after patch removal, and returned to baseline within 2 h of patch removal. Iontophoresis-enhanced delivery through micropores resulted in a two-fold increase in the dose delivered (722 +/- 169 ng) in the hairless rat.

CONCLUSIONS

In vivo delivery of IFNalpha2b was demonstrated through micropores created in the outer layer of the skin. Iontophoresis enhanced delivery through microporated skin in hairless rats.