Bioadhesive patch-based delivery of 5-aminolevulinic acid to the nail for photodynamic therapy of onychomycosis

doi:10.1016/j.jconrel.2004.12.005

Journal of Controlled Release

Volume 103, Issue 2, 21 March 2005, Pages 381-392

https://doi.org/10.1016/j.jconrel.2004.12.005 Get rights and content

Abstract

The in vitro penetration of 5-aminolevulinic acid (ALA) across human nail and into neonate porcine hoof when released from a novel bioadhesive patch containing 50 mg cm⁻² ALA is described. ALA is a naturally occurring precursor of the photosensitiser protoporphyrin IX (PpIX). Topical application of excess ALA bypasses negative feedback inhibition and yields photosensitising concentrations of PpIX at the application site. ALA-based photodynamic therapy (PDT) has been extensively investigated in the topical treatment of various skin neoplasias. Recently, its use has been extended to the microbiological field. If sufficient concentrations of ALA could be achieved within the nail matrix, and at the nail bed, PDT may prove to be a useful treatment for onychomycosis. Patch application for 24 h allowed an ALA concentration of 2.8 mM to be achieved on the ventral side of excised human nail. Application for 48 h induced a concentration of 6.9 mM. Application time had no significant effect on the ALA concentration at mean depths of 2.375 mm in neonate porcine, with application times of 24, 48 and 72 h all producing concentrations of 0.1 mM. Incubation of Candida albicans and Trichophyton interdigitale with ALA concentrations of 10.0 mM for 30 min and 6 h, respectively, caused reductions in viability of 87% and 42%, respectively, following irradiation with red light. Incubation with 0.1 mM ALA for 30 min and 6 h, respectively, caused reductions in viability of 32% for Candida albicans and 6% for Trichophyton interdigitale, following irradiation. Drug penetration across nail may be improved using penetration enhancers, or by filing of the impenetrable dorsal surface of the nail. Moreover, iron chelators can be used to increase PpIX production for a given ALA dose. Therefore, with suitable modifications, ALA-PDT may prove to be a viable alternative in the treatment of onychomycosis.

Introduction

Onychomycosis is a fungal infection of the keratinized tissue of the nail plate [1] that is notoriously difficult to diagnose and treat [2], [3], [4]. The condition accounts for approximately one-third of all fungal skin infections [5] and is increasing in prevalence [6], with a recent survey indicating that from 2–18% of the world population are affected [7]. More importantly, onychomycosis in immunocompromised patients, such as those infected with HIV, can pose a more serious health problem.

Once onychomycosis has been diagnosed, the available treatment modalities that may be considered are topical therapy, systemic (oral) therapy and surgical intervention [7], [8]. However, effective treatment of the condition is notoriously difficult. Topically-applied drugs are generally unable to penetrate the entire nail unit [9]. Systemically administered drugs, such as griseofulvin, ketoconazole and terbinafine, may require up to 12 months of treatment [10]. Furthermore, these agents may be associated with toxicity and potentially serious drug interactions [11], [12]. Development of resistance, especially when used on a long-term basis, also poses concern. Surgical therapy has generally been discontinued due to the pain, disfiguration and potential for permanent scarring that accompanies invasive intervention [13], [14].

Photodynamic therapy (PDT) is defined as a medical treatment by which a combination of a sensitising drug and visible light causes destruction of selected cells [15], [16]. Recently, the use of PDT, based on topical application of 5-aminolevulinic acid (ALA), has been extended from the oncological field to that of antimicrobial chemotherapy. ALA administration has been shown to induce accumulation of the photosensitiser protoporphyrin IX (PpIX) in, and allow subsequent photodynamic destruction of, bacteria [17], [18] and fungi [19]. This study, therefore, reports on a bioadhesive patch containing ALA, first developed in our laboratory for PDT of vulval intraepithelial neoplasia [20] and vulval Paget's Disease [21], as a potential delivery system for use in ALA-PDT of onychomycosis.

Section snippets

Chemicals

Gantrez® AN-139, a copolymer of methylvinylether and maleic anhydride (PMVE/MA), was provided by ISP, Guildford, UK. Plastisol® medical grade poly(vinyl chloride) emulsion containing diethylphthalate as plasticiser, was provided by BASF Coatings, Clwyd, UK. 5-aminolevulinic acid, hydrochloride salt, was purchased from Crawford Pharmaceuticals, Milton Keynes, UK. Radiolabelled 5-aminolevulinic acid solution, 3.7 MBq ml⁻¹ and Ultima Gold® Liquid Scintillation Cocktail were obtained from

ALA penetration of human nail samples

The rate of ALA transfer across the nail was shown to remain constant with respect to time for a considerable portion of the total release time interval, as shown in Fig. 2. After 4 h, the ALA concentration in the receiver phase was approximately 0.5 mM, after 24 h, it was approximately 2.8 mM, after 48 h, it was approximately 4.5 mM and after 72 h, it was approximately 6.9 mM. The large standard deviations observed are typical of those seen in nail penetration experiments [29], [30], [31],

Discussion

The principal manifestations of onychomycosis are hyperkeratosis and discolouration of the nail with other symptoms incorporating onycholysis (detachment of the nail from the nail bed), brittle and damaged nails, paronychial inflammation and thickening of the nail plates [8], [13]. Contrary to common misconception, the condition is not merely a cosmetic affliction [6] but can result in severe pain and the risk of progression to total dystrophy of the nail plate, with a significant adverse

Acknowledgements

The authors gratefully acknowledge the technical assistance of Mrs. Stephanie McGrath with microbiological experiments.

References (40)

G. Midgley et al.
Mycology of nail disorders
J. Am. Acad. Dermatol.
(1994)
P.R. Cohen et al.
Topical and surgical treatment of onychomycosis
J. Am. Acad. Dermatol.
(1994)
R.B. Odom
New therapies for onychomycosis
J. Am. Acad. Dermatol.
(1996)
C.E. Millson et al.
Ex-vivo treatment of gastric Helicobacter infection by photodynamic therapy
J. Photochem. Photobiol., B Biol.
(1996)
X. Hui et al.
Enhanced human nail drug delivery: nail inner drug content assayed by new unique method
J. Pharm. Sci.
(2002)
S. Murdan
Drug delivery to the nail following topical application
Int. J. Pharm.
(2002)
Y. Kobayashi et al.
In vitro permeation of several drugs through the human nail plate: relationship between physicochemical properties and nail permeability of drugs
Eur. J. Pharm. Sci.
(2004)
M.B. Jennings et al.
Study of clinically suspected onychomycosis in a podiatric population
J. Am .Podiatr. Med. Assoc.
(2002)
T.R. Einarson et al.
Clinical and economic factors in the treatment of onychomycosis
PharmacoEconomics
(1996)
R.C. Summerbell
Epidemiology and ecology of onychomycosis
Dermatology
(1997)

D.M. Stier et al.

Patient satisfaction with oral vs nonoral therapeutic approaches in onychomycosis

J. Am. Podiatr. Med. Assoc.

(2001)

R.K. Scher

Onychomycosis: therapeutic update

J. Am. Acad. Dermatol.

(1999)

B.E. Elewski et al.

Update on the management of onychomycosis: highlights of the third annual international summit on cutaneous antifungal therapy

Clin. Infect. Dis.

(1996)

B.E. Elewski

Onychomycosis: pathogenesis, diagnosis and management

Clin. Microbiol. Rev.

(1998)

R.J. Hay

New developments in antifungals

Int. J. Dermatol.

(1999)

H.I. Katz

Possible drug interactions in oral treatment of onychomycosis

J. Am. Acad. Dermatol.

(1997)

C.M. Tom et al.

Management of toenail onychomycosis

Am. J. Health-Syst. Pharm.

(1999)

M.Y. Nahabedian

Multiple-digit onychomycosis: a simple surgical cure

Ann. Plast. Surg.

(2000)

Q. Peng et al.

5-Aminolaevulinic acid based photodynamic therapy

Cancer

(1997)

A. Casas et al.

Tissue distribution and kinetics of endogenous porphyrins synthesized after topical application of ALA in different vehicles

Br. J. Cancer

(1999)

Cited by (100)

Formulation development and characterization of an antifungal nail patch based on Pistacia atlantica gum for transungual treatment of onychomycosis
2023, Journal of Drug Delivery Science and Technology
Recently, there has been considerable interest in using patches as drug carriers for the treatment of numerous diseases. Due to the severe side effects associated with systemic or surgical treatment for onychomycosis, as well as the drug's limited penetration into the nail plate, new methods of local drug administration are required for the treatment of this infection. The primary objective of this study was therefore to develop a novel and, of course, effective formulation of Terbinafine hydrochloride nail patches for the treatment of onychomycosis. In this work, Pistacia atlantica gum was employed for the first time as a natural adhesive agent instead of synthetic polymers. The patches were produced by solvent evaporation and were characterized both physically and biologically. Using Design-Expert software, the response surface method (RSM) was employed to determine the most appropriate formulation. The elongation at break of the optimized patch was 530.38 $\pm$ 25.22% and the modulus was 0.15 $\pm$ 0.02 MPa. Adhesion properties such as tack and peel were 0.32 $\pm$ 0.03 N/mm² and 5.34 $\pm$ 0.52 N/25 mm, respectively. The patch had an aesthetically pleasing appearance and uniform thickness. In addition, the disk diffusion test revealed that the patches had a good antifungal effect, with a considerable growth inhibition zone. It was observed that the patch containing 1% of the active agent would be the most effective. It was most effective against species of Trichophyton verrucosum, with inhibition zone diameters of 88 $\pm$ 1.4 mm, and least effective against species of Trichophyton mentagrophytes, with inhibition zone diameters of 62 $\pm$ 9.4 mm. The cumulative drug amount per unit area after 72 h was approximately 335.43 $\pm$ 4.10 μg/cm². The obtained results indicate that the developed formulation has a potential drug delivery system for the treatment of tinea unguium (onychomycosis).
A drug-in-adhesive anti-onychomycotic nail patch: Influence of drug and adhesive nature on drug release, ungual permeation, in vivo residence in human and anti-fungal efficacy
2022, International Journal of Pharmaceutics
A nail patch is an attractive option for the topical treatment of onychomycosis, although no product is commercially available. We previously identified optimal nail patch formulations for two anti-onychomycotic drugs, based on their properties, as well as those of the other patch components. In this paper, our aim was to further investigate the potential of the patch formulations as topical nail medicines, in particular, whether the drug-in-adhesive patches release drug which then permeates into and through the nail plate and show anti-fungal efficacy, and whether and to what extent they remain adhered to the human nail plate in vivo when tested over 2 week durations. In addition, the influence of the drug (amorolfine HCl, ciclopirox olamine) and PSA (Duro-Tak 2852 or Duro-Tak 202A) on these parameters was determined. We found that both the nature of the drug and of the PSA influenced in vitro drug release. The nature of the drug, but not that of the PSA, influenced ungual drug permeation through human nail clippings, with considerably greater (almost double) permeation for ciclopirox olamine, the smaller and less lipophilic molecule. In vivo residence, tested with 3 out of the 4 patches, excluding the patch where ciclopirox olamine degraded with time, showed greater residence on toenails compared to fingernails reflecting their far lesser exposure to environmental stresses during daily activities. In vivo residence was enhanced when the patch was cut to the shape of the nail, was applied at bedtime, and when a clear colourless nail varnish was applied on top of the patch to ‘seal’ it into place on the nail. Comparison of the patches indicated greater residence of Duro-Tak 202A containing patches over those containing Duro-Tak 2852. Amorolfine HCl in Duro-Tak 202A based patch also showed antifungal efficacy in contrast to Duro-Tak 2852-based patch, and is particularly promising for further development as a potential toenail medicine, remaining almost fully adhered to toenails for at least two weeks.
A facile fabrication of dissolving microneedles containing 5-aminolevulinic acid
2020, International Journal of Pharmaceutics
Photodynamic therapy induced by protoporphyrin IX (PpIX) is widely used to treat precancerous skin lesions. The penetration depth of the prodrug 5-aminolevulinic acid (5-ALA) using topical application is currently limited, which hampers the production of PpIX in deep seated lesions. To enhance 5-ALA delivery in deep skin layers, a soluble microneedles patch (MN-patch) containing 5-ALA has been successfully developed by using a fast solvent casting molding method which could be easily up-scaled. The shape, number and height of the needles have been designed according to the medical application and the mechanical strain necessary for skin insertion. Hyaluronic acid (HA) has been chosen as the needle materials due to its biocompatibility, fast solubility and biodegradation and was mixed with 5-ALA prior to casting. HA-based MN-patch containing 5-ALA have exhibited mechanical properties enabling a good insertion into the skin without significant damages to MN. Interactions between HA and 5-ALA were evaluated by Fourier transform infrared spectroscopy (FTIR) and carbon nuclear magnetic resonance (¹³C NMR), stability of 5-ALA in the MN-patch was monitored by proton nuclear magnetic resonance (¹H NMR) and exhibited a good stability over 5 months after manufacturing. Dissolution rate of the whole patch was completed in 1 hour in ex vivo rat skin without cytotoxicity. Overall, the MN-patch can be a promising technique to enhance 5-ALA penetration and produce PpIX in deeper skin lesions.
The effect of glucose and human serum on 5-aminolevulinic acid mediated photodynamic inactivation of Candida albicans
2020, Photodiagnosis and Photodynamic Therapy
Citation Excerpt :
Shi et al. [37] used 5-ALA at concentration of 15 mM and showed that upon radiation at 300 J cm-2, the cells in Candida albicans biofilms were 74.45 % inhibited. Calzavara‐Pinton et al. [38] investigated patients with interdigital mycoses of the feet and 5-ALA at a concentration of 20 % was applied to the skin lesions for 4 h before irradiation under 75 J cm-2 light dose. It was shown that under these conditions, 5-ALA‐aPDI had good therapeutic effects on interdigital mycosis of the feet.
In response to the growing number of life-threatening infections caused by opportunistic Candida albicans fungi we have examined and discussed the effect of glucose and human serum on the efficiency of photosensitization of C. albicans cells with 5-aminolevulinic acid (5-ALA) used as a precursor of protoporphyrin IX (PpIX). We used 630 nm laser diode as an excitation source to enhance the penetration depth and diminish unwanted light scattering, additionally the experiments were performed in planktonic and biofilm cultures to differentiate the results obtained for cells showing various phenotypic characteristics. Based on performed experiments it became obvious that the incubation of C. albicans fungal cells with 5-ALA in the presence of glucose caused a significant increase in concentration of intracellular PpIX, resulting in a higher efficacy of photo-toxic effect. The observed results were rationalized by the role of glucose as an energy source, which supported the active transport of 5-ALA into cells. In contrary to glucose, the presence of human serum caused a significant reduction in PpIX concentration in C. albicans cells with exogenous delivery of 5-ALA, resulting in a less efficient photo-fungicidal effect. In general, the obtained results contributed to the current search for efficient, light activated anti-fungal treatments of high efficiency.
Newly formulated 5% 5-aminolevulinic acid photodynamic therapy on Candida albicans
2020, Photodiagnosis and Photodynamic Therapy
Citation Excerpt :
Lastly, it is also well tolerated by affected oral mucosal tissues, where 20% ALA is suggested in photodynamic therapy guidelines for the management of oral leucoplakia [29]. Nevertheless, a review of the literature shows evidence of a partial reduction in C. albicans growth but only when treated with high ALA concentrations and/or high light-energy irradiation, which both could cause a potential risk, even to the cells of the infected host organism, or after long incubation and irradiation times [15,19,23,30]. Lately, a new formulation of 5% ALA in thermosetting gel (t) (5% ALA-PTt) has been patented and placed on the market under the name ALADENT.
A large number of systemic diseases can be linked to oral candida pathogenicity. The global trend of invasive candidiasis has increased progressively and is often accentuated by increasing Candida albicans resistance to the most common antifungal medications. Photodynamic therapy (PDT) is a promising therapeutic approach for oral microbial infections. A new formulation of 5-aminolevulinic acid (5%ALA) in a thermosetting gel (t) (5%ALA-PTt) was patented and recently has become available on the market. However, its antimicrobial properties, whether mediated or not by PDT, are not yet known. In this work we characterised them.
We isolated a strain of C. albicans from plaques on the oral mucus membrane of an infected patient. Colonies of this strain were exposed for 1 24 h, to 5%ALA-PTt, 5%ALA-PTt buffered to pH 6.5 (the pH of the oral mucosa) (5%ALA-PTtb) or not exposed (control). The 1 h-exposed samples were also irradiated at a wavelength of 630 nm with 0.14 watts (W) and 0.37 W/cm² for 7 min at a distance of <1 mm.
The 5% ALA-PTt preparation was shown to be effective in reducing the growth of biofilm and inoculum of C. albicans. This effect seems to be linked to the intrinsic characteristics of 5%ALA-TPt, such acidic pH and the induction of free radical production. This outcome was significantly enhanced by the effect of PDT at relatively short incubation and irradiation times, which resulted in growth inhibition of both treated biofilm and inoculum by ∼80% and ∼95%, respectively.
Determination and validation of mycophenolic acid by a UPLC-MS/MS method: Applications to pharmacokinetics and tongue tissue distribution studies in rats
2020, Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences
Mycophenolic acid (MPA) has being used clinically for organ rejection prophylaxis. Recent studies have revealed that MPA can also act as a chemo-sensitizing agent when used in combination with various chemotherapeutic agents in a cancer type-specific manner, including with oxaliplatin on oral squamous cell carcinoma (OSCC) cells. To prepare for the analysis of a novel drug delivery route for MPA absorption via oral mucosa as a potential therapeutic product, it is essential to develop and validate a highly sensitive analytical method for the quantification of MPA in biological samples for pharmacokinetic and tissue distribution studies. Herein, we report a sensitive, specific and reproducible UPLC-MS/MS method to do so. Blank rat plasma or tongue tissue homogenates coupled with griseofulvin, as internal standard, was used for generating standard curves ranging from 0.5 to 1000 ng/mL (r > 0.9990) for both plasma and tongue tissue homogenates. The chromatographic separation was achieved by a reverse phase ACE Excel 2 Super C₁₈ column with a flow rate of 0.4 mL/min under gradient elution. Mass detection was performed under positive ionization electrospray. Inter- and intra-day accuracy and precision of the assay were ≤15% in both plasma and tongue tissue homogenates. The matrix effect was non-significant and extraction recovery rates were within 87.99% and 109.69% in plasma and tongue homogenates, respectively. The validity of this assay has been confirmed by measuring MPA in rat plasma for pharmacokinetics following intravenous administration of 0.5 mg/kg of mycophenolate sodium, as well as monitoring MPA in rat tongues for tissue distribution and detecting MPA that diffused into systemic circulation following a 4-h transmucosal delivery of 357 μg/cm² of mycophenolate sodium.

View all citing articles on Scopus

View full text

Bioadhesive patch-based delivery of 5-aminolevulinic acid to the nail for photodynamic therapy of onychomycosis

Abstract

Introduction

Section snippets

Chemicals

ALA penetration of human nail samples

Discussion

Acknowledgements

J. Am. Acad. Dermatol.

J. Am. Acad. Dermatol.

J. Am. Acad. Dermatol.

J. Photochem. Photobiol., B Biol.

J. Pharm. Sci.

Int. J. Pharm.

Eur. J. Pharm. Sci.

Study of clinically suspected onychomycosis in a podiatric population

J. Am .Podiatr. Med. Assoc.

Clinical and economic factors in the treatment of onychomycosis

PharmacoEconomics

Epidemiology and ecology of onychomycosis

Dermatology

Patient satisfaction with oral vs nonoral therapeutic approaches in onychomycosis

J. Am. Podiatr. Med. Assoc.

Onychomycosis: therapeutic update

J. Am. Acad. Dermatol.

Update on the management of onychomycosis: highlights of the third annual international summit on cutaneous antifungal therapy

Clin. Infect. Dis.

Onychomycosis: pathogenesis, diagnosis and management

Clin. Microbiol. Rev.

New developments in antifungals

Int. J. Dermatol.

Possible drug interactions in oral treatment of onychomycosis

J. Am. Acad. Dermatol.

Management of toenail onychomycosis

Am. J. Health-Syst. Pharm.

Multiple-digit onychomycosis: a simple surgical cure

Ann. Plast. Surg.

5-Aminolaevulinic acid based photodynamic therapy

Cancer

Tissue distribution and kinetics of endogenous porphyrins synthesized after topical application of ALA in different vehicles

Br. J. Cancer