Conformability and irritancy of adhesive tapes on the skin

Development of Drug-in-Adhesive Patch with a Honeycomb Film as a Backing Layer

Excess stripping of stratum corneum (SC) layers by patch-peeling from the skin surface is one cause of skin irritation. High SC hydration by patch occlusion may also cause skin irritation, although the occlusive technique is preferable to increase the skin permeation of topically applied drugs. In the present study, film having a honeycomb structure was selected as the backing layer of a drug-in-adhesive (DIA) patch to reduce peeling of the SC without losing adhesion force to the skin surface, as well as decreasing the skin permeation of a model drug, tulobuterol. The usefulness of the DIA patch with honeycomb film was evaluated by transepidermal water loss (TEWL) changes, amount of SC removed by patch-peeling, distribution pattern of removed SC on the adhesive layer, and water permeation through the patch. Furthermore, skin permeation and release profiles of tulobuterol from the DIA patch were investigated. Significantly (p<0.05) less TEWL change was observed after removal of the patch with a honeycomb film compared with the conventional pressure-sensitive adhesive patch, and no difference in tulobuterol permeation through skin from the patches was confirmed regardless of the type of backing layer. In addition, a lower amount of SC was removed by the peeling of the patch with a honeycomb film. The results suggest that DIA patches with a honeycomb film as a backing layer may be used to achieve less SC removal without reducing the skin permeation of drugs.

Practical management of cutaneous reactions to the methylphenidate transdermal system: recommendations from a dermatology expert panel consensus meeting

BACKGROUND

Psychostimulants remain the most-used medications for attention-deficit/hyperactivity disorder (ADHD). The methylphenidate transdermal system (MTS) is the first stimulant patch dosage formulation to be approved by the US Food and Drug Administration for the treatment of the symptoms of ADHD in children aged 6 to 12 years. The MTS patch is approved to be applied once daily to the hip and worn for 9 hours. While cutaneous reactions may occur with any formulation of medication, they are more likely with transdermal administration.

OBJECTIVE

The purpose of this commentary was to describe the types of cutaneous reactions that have been reported with transdermal systems in general, review the cutaneous adverse events seen in clinical trials with the MTS specifically, and provide practical management suggestions for prevention and treatment of these potential cutaneous reactions.

METHODS

In September 2007, a group of child psychiatrists, pediatricians, developmental pediatricians, and pediatric neurologists who treat ADHD and have had experience in their practices with MTS convened to discuss cutaneous reactions in relation to its use. Information collected from this meeting and from the clinical trials database of the sponsor was reviewed by a panel of 3 dermatologic clinical experts in contact dermatitis and 1 pediatric dermatologist. The panel's recommendations form the basis for this report.

CONCLUSIONS

Mild to moderate erythema is a common cutaneous effect with MTS use, and is generally not a cause for discontinuation if seen in isolation. Irritant contact dermatitis is relatively common and can be reduced and treated by alternating patch application sites, moisturizing, gentle skin care, and application of topical corticosteroids at the previous patch sites if needed. Allergic contact dermatitis (ACD) and allergic contact urticaria are rare when MTS is worn as directed in the prescribing information. MTS should be discontinued if ACD is suspected.

Properties of pressure-sensitive adhesive tapes with soft adhesives to human skin and their mechanism

BACKGROUND/PURPOSE

The use of soft adhesives in the manufacture of pressure-sensitive adhesive tapes has recently increased. The dermal peeling force of adhesive tapes with soft adhesives was studied.

METHODS

Four kinds of adhesive tapes with adhesives of different softness were made, by adding varying amounts of isopropyl myristate as a softener. The tapes were applied on the flexor side of the forearm of six healthy male volunteers. The dermal peeling force, the amount of stripped corneocytes, the level of pain when the tapes were removed and the degree of penetration of adhesives into the sulcus cutis (skin furrows) were evaluated at 1 and 24 h after application of the tapes. Furthermore, a skin model panel (a sulcus cutis and crista cutis model panel) and a crista cutis model panel were constructed from a general stainless-steel panel, and the peeling force of the tapes against the model panels was measured.

RESULTS AND CONCLUSION

As the softness of adhesives increased, the peeling force against a general stainless-steel panel with a flat surface decreased, although the peeling force against human skin did not significantly change. The amount of stripped corneocytes on the removed tapes and the level of pain when the tapes were removed decreased with the increase in softness of the adhesives. These results suggest that adhesive tapes with soft adhesives that contain isopropyl myristate as a softener are suitable for the skin. Furthermore, the degree of penetration of adhesive into the sulcus cutis increased as the softness of adhesives increased. Upon evaluation of the peeling force against the model panels, as the softness of adhesives increased, there was a slight decrease in the peeling force against the skin model panel, while there was a remarkable decrease in the peeling force against the crista cutis model panel. These results suggest that the lack of change in the dermal peeling force as the softness of adhesives increased was caused by penetration of soft adhesive into the sulcus cutis, and that the decrease in the amount of stripped corneocytes was caused by a decrease in the peeling force against the crista cutis, which consists of corneocytes mainly removed by the tapes.

Skin Irritation in Transdermal Drug Delivery Systems: A Strategy for its Reduction

PURPOSE

Active pharmaceutical ingredients (API) in transdermal drug delivery systems (TDS) often causes skin irritation such as erythema and edema. We have studied a possible approach for the reduction of skin irritation by patch formulations that control the rates of skin permeation and elimination of API.

METHODS

Loxoprofen (LX-base) was used to induce the skin irritation. The redness value (Deltaa) was evaluated as a measure of erythema by Chroma Meter. The in vitro skin permeation and release profiles were also investigated by using a side-by-side diffusion cell.

RESULTS

The redness values were not correlated either with the cumulative amount of API permeated or the concentration of LX-base in the skin, but well correlated with the elimination rate of LX-base from the skin after the removal of the formulation. The formulation with gradual decrease of permeation rate during application accelerated the elimination rate after application, and resulted in the reduction of the skin irritation.

CONCLUSIONS

The skin pharmacokinetics of API, not only permeation during application but also release after the patch removal, was found to be a significant factor for skin irritation. To minimize the skin irritation, it's also important to eliminate the residual API in the skin promptly after application.

Use of adhesive surgical tape with the absorbable continuous subcuticular suture

BACKGROUND

The absorbable continuous subcuticular suture is frequently used to close surgical incisions where the aim is healing by primary intention. A form of adhesive surgical tape is commonly also placed over the wound but this combination closure seems to have its development based on anecdotal, rather than experimental evidence. The present study reviews the scientific literature on the development of sutureless wound closure and presents the current evidence for the use of combination wound closure.

METHODS

Review was undertaken of the medical literature using the PubMed Internet database and cross-referencing major -articles on the subject. The following combinations of key words were searched: skin closure, wound closure, suture technique, sutureless, adhesive tape, op-site, staples, subcuticular suture, complication, infection and scars.

RESULTS

Taped closure alone has advantages of lower wound infection rates and greater wound tensile strength, but disadvantages of epidermal reaction, skin edge inversion, doubtful safety and time required for meticulous surgical technique. The use of the continuous absorbable subcuticular suture allows accurate skin edge approximation, which increases the safety margin. The combination closure has a slightly superior cosmetic result to sutureless techniques but no study has been performed to compare the results of combination subcuticular suture and tape, with tape or subcuticular suture alone.

CONCLUSIONS

There is no evidence in the scientific literature to justify or support the practice of closing a surgical wound with both subcuticular suture and adhesive surgical tape.

Influence of patch-test application tape on reactions to sodium dodecyl sulfate

There remains much room for improvement in the accuracy of the patch test procedure. There has been a lack of knowledge regarding the possible relationship between the intensity of test reactions and the quality of the tape used to apply patch tests. Using different brands of tape, patches coated with 2 mg/cm2 sodium dodecyl sulfate (SLS) were applied for 24 h to the backs of 10 volunteers. The tape specimens varied in terms of manufacture, elasticity, adhesive strength, and water permeability. The intensity of patch test reactions, evaluated visually and objectively with both the high resolution laser Doppler perfusion imaging technique (HR-LDPI) and transepidermal water loss measurements (TEWL), varied significantly with the different brands of tape. Observed variations in the intensity of reactions to the patch tests could not be explained by any of the 4 tape parameters investigated. In order to attain optimal test quality in the future, both the tape and patches used in the testing system should be standardized and clearly labelled.