International consensus recommendations on face transplantation: A 2-step Delphi study.

Face transplantation is a viable reconstructive approach for severe craniofacial defects. Despite the evolution witnessed in the field, ethical aspects, clinical and psychosocial implications, public perception, and economic sustainability remain the subject of debate and unanswered questions. Furthermore, poor data reporting and sharing, the absence of standardized metrics for outcome evaluation, and the lack of consensus definitions of success and failure have hampered the development of a "transplantation culture" on a global scale. We completed a 2-round online modified Delphi process with 35 international face transplant stakeholders, including surgeons, clinicians, psychologists, psychiatrists, ethicists, policymakers, and researchers, with a representation of 10 of the 19 face transplant teams that had already performed the procedure and 73% of face transplants. Themes addressed included patient assessment and selection, indications, social support networks, clinical framework, surgical considerations, data on patient progress and outcomes, definitions of success and failure, public image and perception, and financial sustainability. The presented recommendations are the product of a shared commitment of face transplant teams to foster the development of face transplantation and are aimed at providing a gold standard of practice and policy.

Achieving the next level in cleft speech intervention: A protocol of a randomized sham-controlled trial to provide guidelines for a personalized approach in children with cleft palate.

BACKGROUND: Compensatory cleft speech disorders can severely impact speech understandability and speech acceptability. Speech intervention is necessary to eliminate these disorders. There is, however, currently no consensus on the most effective speech therapy approach to eliminate the different subtypes of compensatory cleft speech disorders. AIMS: To compare the immediate, short- and long-term effects of three well-defined speech intervention approaches (i.e., a motor-phonetic approach, a linguistic-phonological approach and a combined phonetic-phonological approach) on the speech and health-related quality of life (HRQoL) in Belgian Dutch-speaking children with cleft palate with or without cleft lip (CP±L) and different subtypes of compensatory speech disorders (i.e., anterior oral cleft speech characteristics (CSCs), posterior oral CSCs or non-oral CSCs). Besides, the perceived acceptability of these three speech intervention approaches will be investigated from the perspectives of caregivers and children with a CP±L. METHODS & PROCEDURES: A two-centre longitudinal randomized sham-controlled trial was used. Children were randomly assigned to one of the three intervention programmes and received 10 h of speech intervention divided over 2 weeks. Block randomization was used, stratified by age and gender. Primary outcome measures included perceptual speech outcomes. Secondary outcome measures included patient-reported outcomes. OUTCOMES & RESULTS: The results of this trial will provide speech-language pathologists evidence-based guidelines to better tailor intervention approaches to the specific needs of a child with a defined compensatory speech disorder. WHAT THIS PAPER ADDS: What is already known on this subject Speech therapy approaches to address cleft palate speech disorders are broadly divided into two categories: motor-phonetic interventions and linguistic-phonological interventions. Some limited evidence demonstrated the positive effects of these approaches in eliminating compensatory cleft speech disorders. Different studies have reported inter-individual variation, suggesting that one child may benefit more from a particular intervention approach than the other child. Perhaps this variation can be attributed to the specific subtype of compensatory speech disorder (i.e., anterior oral CSC, posterior oral CSC or non-oral CSC). What this paper adds to existing knowledge This paper describes a randomized sham-controlled trial that compared the immediate, short- and long-term effects of three well-defined speech intervention approaches (i.e., a motor-phonetic approach, a linguistic-phonological approach and a combined phonetic-phonological approach) on the speech and HRQoL in Belgian Dutch-speaking children with CP±L and different subtypes of compensatory cleft speech disorders (i.e., anterior oral CSCs, posterior oral CSCs or non-oral CSCs) measured by perceptual and psychosocial outcome measures. Besides, the experienced acceptability of these three speech intervention approaches were investigated from the perspectives of caregivers and children. What are the potential or actual clinical implications of this work? This project provides evidence-based knowledge on patient-tailored cleft speech intervention considering both scientific evidence and the perspectives of caregivers and children. The results aid SLPs in better tailoring intervention approaches to the needs of a child with a specific type of compensatory cleft speech disorder.

Facial Allograft Donation: An Interpretative Phenomenological Analysis of the Experiences of Family Members.

Facial allograft transplantation can be regarded as a particular and complex type of donation because of its perceptibility and the importance of the face as an identity characteristic. As research on this topic is currently lacking, the objective of this study is to explore the experiences of the family members of the donor in facial allograft donation. In-depth, semi-structured interviews were conducted separately with the donor's family members and analyzed using interpretative phenomenological analysis. Six themes were identified: (1) Contrasting facial donation to that of more commonly donated organs; (2) Consenting to facial donation; (3) Expectations towards the recipient of the facial graft; (4) Expectations and consequences of restoration of the donor's face; (5) Relationship with the medical team during the process; and (6) Media attention. The findings of our study help to better support donor families through the facial donation process and to improve facial transplantation procedures.

Clinical applications of the chimeric anterolateral thigh (ALT) flap in head and neck reconstruction.

BACKGROUND: Surgical site infection (SSI) is a common complication following head and neck surgery. Dead space at the excision site can increase the risk of infection, abscess formation, and mortality. Herein, we evaluated the performance of the chimeric anterolateral thigh (ALT) flap in addressing these concerns. METHODS: Patients who underwent oncologic head and neck reconstruction between October 2016 and November 2021 were divided in two groups: a normal ALT flap and a chimeric dead space filling (DSF) ALT-vastus lateralis flap group. We evaluated the postoperative outcomes. RESULTS: Twenty-five patients treated with normal ALT flaps (34.7%) and 47 with DSF ALT flap group (65.2%) were included. Only one ALT per case was necessary. Most of the cases involved tongue (31.9%) and lower gingival reconstruction (27.8%). The time to harvest the DSF ALT flap was 134.3 min when compared to the normal ALT flap (116.2 min, p < .001). Vascular occlusion, flap loss, partial necrosis, and fat necrosis were not observed among the different groups. CONCLUSION: The DSF process can be used as a preventive measure for SSI or vessel exposure due to radiation-induced skin damage. This flap allows same-site reconstruction if the primary tumor recurs by using the pedicle of the chimeric flap for reattachment of another free flap.

Use of Dental Impression Silicone to Fabricate Simple Surgical Guides in Mandibular Reconstruction∗.

BACKGROUND: Several recent reports have described the development and use of three-dimensional (3D) printed surgical osteotomy guides. However, these methods: are usually costly. Here, we introduce a novel method of manufacturing surgical guides built from inexpensive, easy-to-use, and sterilizable dental impression silicone. METHODS: Mandibular and fibular models were prepared using a 3D printer for 10 patients undergoing free fibula flap transfer after mandibular resection. During preoperative simulation surgery, Protesil labor, a dental silicone, was molded to the same size as the fibular models to act as surgical guides. RESULTS: The authors compared pre- and post-operative bone angles and bone lengths for all cases using simulation surgery models and postoperative 3D computed tomography. Mean bone angle difference was 2.6° and mean bone length difference was 1.7 mm. Cost of the dental silicone was approximately US$5/patient. CONCLUSIONS: In our series this method allowed the surgeon to perform an accurate osteotomy, inexpensively and time-efficiently.

Surgical treatment of pressure injuries in children: A multicentre experience.

Pressure injuries (PI) are infrequent in paediatric patients, prevalence estimates ranging from 1.4% to 8.2%, and reaching values as high as 43.1% in critical care areas. They can be associated with congenital neurological or metabolic disorders that cause reduced mobility or require the need for medical devices. In children, most pressure injuries heal spontaneously. However, a small percentage of ulcers that is refractory to conservative management or is too severe at presentation (Stage 3 or 4) will be candidates for surgery. We retrospectively reviewed the clinical history of paediatric patients affected by pressure injuries from four European Plastic Surgery Centres. Information was collected from clinical and radiology records, and laboratory reports. An accurate search of the literature revealed only two articles reporting on the surgical treatment of pressure injuries in children. After debridement, we performed surgical coverage of the pressure injuries. We report here our experience with 18 children aged 1-17 years, affected by pressure injury Stages 3 and 4. They were successfully treated with pedicled (17 patients) or free flaps (1 patient). The injuries involved the sacrum (6/18 patients), lower limb (3/18 patients), thoracic spine (2/18 patients), ischium (3/18 patients, bilateral in one patient), temporal area (3/18 patients), hypogastrium (1/18 patients) and were associated to medical devices in three cases. Flaps were followed for a minimum of 19 months and up to 13 years. Only two patients developed true recurrences that were treated again surgically. Pressure injuries are infrequent in children and rarely need surgical treatment. Pedicled flaps have a high success rate. Recurrences, contrary to what is reported in the literature, were rare.

Stages in the Development and Validation of a Belgian Dutch Outcome Tool for the Perceptual Evaluation of Speech in Patients With Cleft Palate.

OBJECTIVE: To develop and validate a Belgian Dutch outcome tool for the perceptual evaluation of speech in patients with cleft palate. SETTING: Cleft palate team in a tertiary university hospital. METHODS: The tool was based on the Cleft Audit Protocol for Speech-Augmented (John et al., 2006; Sell et al., 2009), with adaptations to some of the speech variables and the structured listening protocol. Following a preliminary listening experiment in phase 1, the tool was optimized. In the second phase, a listening experiment with 4 experienced listeners was set up to assess face validity, inter- and intrarater reliability and criterion validity. RESULTS: Results of phase 1 indicated good to very good inter- and intrarater reliability for the majority of the speech variables, good discriminant validity, and varying sensitivity and specificity based on a comparison with nasalance values and the Nasality Severity Index 2.0 (criterion validity). Results of phase 2 showed good to very good interrater reliability for 5 of the 14 variables and good intrarater reliability in 3 of the 4 experienced listeners. Sensitivity and specificity were sufficient, except the specificity of the hypernasality judgments in comparison with the nasalance values of the oral text. Overall, listeners positively judged the face validity of the tool. CONCLUSION: The 2-phase evaluation indicated varying validity and reliability results. Future studies will aim to optimize validity and reliability of the developed tool based on adaptations to the listening protocol, the addition of speech variables, and the inclusion of a more elaborate training.

Sustainable Cleft Care Through Education: The First Simulation-Based Comprehensive Workshop in the Middle East and North Africa Region.

OBJECTIVE: To describe the conduct of the first multidisciplinary simulation-based workshop in the Middle East/North Africa region and evaluate participant satisfaction. DESIGN: Cross-sectional survey-based evaluation. SETTING: Educational comprehensive multidisciplinary simulation-based cleft care workshop. PARTICIPANTS: Total of 93 workshop participants from over 20 countries. INTERVENTIONS: Three-day educational comprehensive multidisciplinary simulation-based cleft care workshop. MAIN OUTCOME MEASURES: Number of workshop participants, number of participants stratified by specialty, satisfaction with workshop, number of workshop staff, and number of workshop staff stratified by specialty. RESULTS: The workshop included 93 participants from over 20 countries. The response rate was 47.3%, and participants reported high satisfaction with all aspects of the workshop. All participants reported they would recommend it to colleagues (100.0%) and participate again (100.0%). No significant difference was detected based on participant specialty or years of experience. The majority were unaware of other cleft practitioners in their countries (68.2%). CONCLUSION: Multidisciplinary simulation-based cleft care workshops are well received by cleft practitioners in developing countries, serve as a platform for intellectual exchange, and are only possible through strong collaborations. Advocates of international cleft surgery education should translate these successes from the regional to the global arena in order to contribute to sustainable cleft care through education.

Intracranial complications of midline nasal dermoid cysts.

BACKGROUND: Nasal dermoid cysts are common tumors in children. Due to anomalies in embryologic development of the nasal complex, sometimes an intracranial extension exists. When these cysts become infected they can lead to meningitis, brain abscess and death. METHODS: We report the case of a 1.5-year-old girl admitted to the paediatric intensive care unit after infection of a nasal dermoid cyst. RESULTS: The infant had a spiking fever and epileptic seizures. She was stabilized, intubated and a CT scan showed a subcutaneous mass with an adjacent zone of encephalitis and brain abscess formation. Neurosurgical interventions were necessary to lower intracranial pressure and control infectious spread. After a hospital stay of 69 days the child could be discharged. Due to her young age, irreversible brain damage is expected. CONCLUSION: Nasal midline dermoid cysts are considered benign swellings. When an intracranial extension exists, infection can lead to deleterious complications. It is important for health care practitioners to be aware of this imminent risk. Suspicion of a nasal midline dermoid cyst should prompt a careful clinical work-up with an ultrasound followed by CT or MRI imaging. The treatment is complete excision to avoid disastrous complications and recurrences.

Oral habits in Children with Cleft (Lip and) Palate: A Pilot Study.

BACKGROUND/AIMS: This pilot study aimed to evaluate the occurrence of oral habits and non-nutritive sucking habits in children with cleft (lip and) palate (CL/P) between 0-12 years, compared to peers without CL/P. METHODS: Children with CL/P (mean age 6.0 years, SD 2.80) were recruited from the Ghent University Hospital and compared to gender- and age-matched children without CL/P (mean age 5.8 years, SD 3.09). A self-report questionnaire was developed and given to the caregivers. To compare the occurrence of oral habits and non-nutritive sucking habits in children with and without CL/P, χ2 tests or Fisher's exact tests were used. RESULTS: The present study revealed a significantly lower occurrence of non-nutritive sucking habits in children with CL/P. These children showed significantly less pacifier sucking; no significant difference was found regarding thumb or finger sucking nor regarding sucking on other objects. Additionally, the results showed that the occurrence of snoring was statistically significantly higher in children with CL/P. CONCLUSION: Children with CL/P show less non-nutritive sucking habits, but more snoring compared to a control group without CL/P. Although further research regarding the oral habits in children with CL/P is necessary, cleft teams should give attention to the occurrence of oral habits.

Recurrent Mutations in the Basic Domain of TWIST2 Cause Ablepharon Macrostomia and Barber-Say Syndromes.

Ablepharon macrostomia syndrome (AMS) and Barber-Say syndrome (BSS) are rare congenital ectodermal dysplasias characterized by similar clinical features. To establish the genetic basis of AMS and BSS, we performed extensive clinical phenotyping, whole exome and candidate gene sequencing, and functional validations. We identified a recurrent de novo mutation in TWIST2 in seven independent AMS-affected families, as well as another recurrent de novo mutation affecting the same amino acid in ten independent BSS-affected families. Moreover, a genotype-phenotype correlation was observed, because the two syndromes differed based solely upon the nature of the substituting amino acid: a lysine at TWIST2 residue 75 resulted in AMS, whereas a glutamine or alanine yielded BSS. TWIST2 encodes a basic helix-loop-helix transcription factor that regulates the development of mesenchymal tissues. All identified mutations fell in the basic domain of TWIST2 and altered the DNA-binding pattern of Flag-TWIST2 in HeLa cells. Comparison of wild-type and mutant TWIST2 expressed in zebrafish identified abnormal developmental phenotypes and widespread transcriptome changes. Our results suggest that autosomal-dominant TWIST2 mutations cause AMS or BSS by inducing protean effects on the transcription factor's DNA binding.

Facing a New Face: An Interpretative Phenomenological Analysis of the Experiences of a Blind Face Transplant Patient and His Partner.

Increasing evidence points to good functional, aesthetic, and psychosocial outcomes after face transplantation. However, research investigating how patients and their families subjectively experience the transplantation process is lacking thus far. This study aims to investigate the personal experiences of a blind face transplant patient and his partner. In-depth interviews exploring different experiences were conducted with both partners separately 20 months after face transplantation. The interviews were analyzed using interpretative phenomenological analysis. Seven themes were identified in both interviews: coping with the facial trauma, motivation for the face transplantation, outcomes of the face transplantation, acceptance of the new face, gratitude toward the donor family, relation to the medical team, and dealing with the media. Two further themes were only mentioned by the patient (coping with complications and coping with blindness) and one theme only by the partner (loss of choices). The results of this study increase our understanding of the transplantation process as experienced by a face transplant recipient and his partner. They may help to better inform professionals to optimize transplantation procedures or supportive interventions.

Post Surgical Pyoderma Gangrenosum in flap surgery: diagnostic clues and treatment recommendations.

BACKGROUND: Post Surgical Pyoderma Gangrenosum (PSPG) is a neutrophilic dermatosis causing aseptic necrotic ulcerations within surgical sites. It is often misdiagnosed as infection or ischemia and worsened by the inappropriate treatment. Therefore diagnostic clues must be identified and awareness for PSPG raised. METHODS: We present two cases of PSPG after flap surgery and a review of the literature. RESULTS: Seventeen cases of PSPG after flap surgery were found. Fever, pain and redness are the most common initial symptoms. In 63%, lesions were on the flap and the adjacent skin. In 63%, the donor site is also involved. Time to diagnosis was nine days to four years. Frequent debridement (89%) and administration of antibiotics (74%) illustrate the misdiagnosis of infection or ischemia. PSPG in flap surgery seems to be less associated with underlying diseases, than other forms of Pyoderma Gangrenosum. Corticoids are the most commonly used treatment. Of the 19 cases, 10 experienced partial or total flap loss. CONCLUSION: PSPG must be included in the differential diagnosis of postoperative wound problems. Recognizing the diagnostic clues can lead to early diagnosis and treatment with systemic immunotherapy. Associated diseases should be investigated and additional surgery can only be successful when associated with immunotherapy.

Barber-Say syndrome and Ablepharon-Macrostomia syndrome: An overview.

Barber-Say syndrome (BSS) and Ablepharon-Macrostomia syndrome (AMS) are congenital malformation syndromes caused by heterozygous mutations in TWIST2. Here we provide a critical review of all patients published with these syndromes. We excluded several earlier reports due to misdiagnosis or insufficient data for reliable confirmation of the diagnosis. There remain 16 reliably diagnosed individuals with BSS and 16 with AMS. Major facial characteristics present in both entities, albeit often in differing frequencies, are excessive facial creases, hypertelorism, underdevelopment of the anterior part of the eyelids (anterior lamella), ectropion, broad nasal ridge and tip, thick and flaring alae nasi, protruding maxilla, wide mouth, thin upper vermillion, and attached ear lobes. In BSS a remarkable extension of the columella on the philtrum can be seen, and in both the medial parts of the cheeks bulge towards the corners of the mouth (cheek pads). Scalp hair is sparse in AMS only, but sparse eyebrows and eyelashes occur in both entities, and general hypertrichosis occurs in BSS. We compare these characteristics with those in Setleis syndrome which can also be caused by TWIST2 mutations. The resemblance between the three syndromes is considerable, and likely differences seem larger than they actually are due to insufficiently complete evaluation for all characteristics of the three entities in the past. It is likely that with time it can be concluded that BSS. AMS and Setleis syndrome form a continuum. © 2016 Wiley Periodicals, Inc.

Facial transplantation in a blind patient: psychologic, marital, and family outcomes at 15 months follow-up.

BACKGROUND: Quality of life has frequently been reported to improve after vascularized composite allotransplantation of the face. However, psychosocial functioning of the partner or of particular patient groups such as blind patients are until now less well investigated. OBJECTIVE: The aim of this study is to investigate psychologic, marital, and family functioning of a blind 54-year-old patient, Mr. A, and his partner after facial transplantation. METHODS: Depressive and anxiety symptoms, hopelessness, personality, coping, resilience, illness cognitions, marital support, dyadic adjustment, family functioning, and quality of life of Mr. A and his partner were assessed before and after facial transplantation and at 15 months follow-up. Reliable change index (RCI) was further calculated to evaluate the magnitude of change. RESULTS: Most psychologic, marital, and family scores of both Mr. A and his partner were within a normative and healthy range before and after transplant and at 15 months follow-up. Resilience (RCI: 3.6), affective responsiveness (RCI: -3.6), and disease benefits (RCI: 2.6) of Mr. A further improved at 15 months follow-up whereas the physical quality of life (RCI: -14.8) strongly decreased. Only marital support (RCI: -2.1) and depth (RCI: -2.0) of the partner decreased at 15 months. CONCLUSIONS: The results of this study point to positive psychosocial outcomes in a blind patient after facial transplantation. Further, they may underscore the importance of good psychosocial functioning before transplantation of both partners and of their involvement in psychologic and psychiatric treatment. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

The influence of the acyl chain on the transdermal penetration-enhancing effect of synthetic phytoceramides.

BACKGROUND/AIMS: The skin has become very attractive as a route for drug administration. Optimization of topical drug formulations by the addition of penetration enhancers may facilitate the passage of drugs through the stratum corneum. METHODS: In this paper, the skin penetration effect of phytosphingosine and 9 derived phytoceramides (PCERs) on 3 transdermal model drugs (i.e. caffeine, testosterone, ibuprofen) was investigated via Franz diffusion cell experiments using split-thickness human skin. Azone was included as a positive control. RESULTS: The main finding in our study was that the PCERs exerted a compound-dependent penetration-enhancing effect. Some of the investigated PCERs exhibited a penetration-enhancing ratio of more than 2 (mean ± SE): for caffeine PCER1 (2.48 ± 0.44), PCER2 (2.75 ± 0.74), PCER3 (2.62 ± 0.93) and PCER6 (2.70 ± 0.45) and for testosterone PCER1 (2.08 ± 0.56), PCER2 (2.56 ± 0.13), PCER3 (3.48), PCER4 (2.53), PCER5 (2.04 ± 0.14), PCER6 (2.05 ± 0.48) and PCER10 (4.84 ± 0.79), but none of them had an influence on ibuprofen. CONCLUSION: The investigated PCERs exhibited a penetration-enhancing effect on caffeine and testosterone but not on ibuprofen.

Long-Term Multifunctional Outcome and Risks of Face Vascularized Composite Allotransplantation.

Vascularized composite allotransplantation (VCA) to reconstruct complex centrally located facial defects and to restore vital functions in a 1-staged procedure has worldwide gained acceptance. Continuous long-term multidisciplinary follow-up of face transplant patients is mandatory for surveillance of the complications associated with the immunosuppressive regime and for functional assessment of the graft. In December 2011, our multidisciplinary team performed a digitally planned face transplant at the Ghent University Hospital, Belgium on a 55-year-old man with a large central facial defect after a high-energy ballistic injury. The patient was closely followed to assess functional recovery, immunosuppressive complications, overall well-being, and quality of life. Three years postoperatively, the patient and his family are very satisfied with the overall outcome, and social reintegration in the community is successful. Motor and sensory functions have recovered near normal. Infectious and medical complications have been serious but successfully managed. Immunosuppressive maintenance therapy consists of corticoids, tacrolimus, and mycophenolate mofetil in minimal doses. Epithetic reconstruction of both eyes gave a tremendous improvement on the overall aesthetic outcome. Despite serious complications during the first 12 months, multifunctional outcome in the first face transplant in Belgium (#19 worldwide) is successful. This should be attributed to the continuous and long-term multidisciplinary team approach. As only few reports of other face transplant patients on long-term follow-up are available, more data need to be collected and reported to further outweigh the risk benefit ratio of this life changing surgery.

Technical recommendations for penile replantation based on lessons learned from penile reconstruction.

Penile amputation is an exceptional surgical emergency. Immediate replantation yields a high success and low complication rate. We report a case of a self-inflicted penile amputation treated with successful microsurgical replantation. Postoperative edema caused minor skin slough and temporary venous congestion was treated with medicinal leech therapy. Follow-up at 18 months showed normal subjective sensation; voiding and erectile function were present. Surgical management and technique refinements are discussed, based on a review of the literature and on our experience in penile reconstruction.

Barber-Say syndrome in a father and daughter.

We report on a father to daughter transmission of Barber-Say syndrome (BSS), a rare, congenital disorder characterized by severe generalized hypertrichosis, macrostomia, ocular telecanthus, bulbous nose and atrophic skin. These two cases further support the autosomal dominant inheritance. Both presented with the typical BSS symptoms but the phenotypic expression in the father was milder. Treatment is challenging for both patients and doctors, requiring a multidisciplinary approach.

A new discriminative criterion for the development of Franz diffusion tests for transdermal pharmaceuticals.

PURPOSE: In vitro skin/membrane permeation profiling of topical pharmaceuticals is an important overall quality attribute in the evaluation of product consistency and it is also used for IVIVR (in vitro - in vivo relationship) purposes in product development and change control. Franz diffusion cell (FDC) experiments are emerging as a generally accepted methodology in this field, where the choice of operational conditions requires a data-supported justification towards the discriminating power of the test. A response function is therefore proposed to objectively quantify the discriminating power. METHODS: We evaluated the usefulness of the proposed response function by studying one of the operational conditions, i.e. the influence of receptor medium composition, on the FDC in vitro penetration behaviour of the model compound testosterone formulated in four different topical preparations, using both artificial membranes and dermatomed human skin. RESULTS: From the obtained cumulative amount of testosterone in the receptor fluid versus time curves, the permeability coefficient Kp of testosterone from each formulation was calculated. The evaluation of the discriminating power of the different media was performed using our new objective response function based upon an equal spread criterion of normalised Kp values. CONCLUSION: We demonstrated significant differences in discriminating power between the different media used, with the overall best results obtained with hydroxypropyl-beta-cyclodextrine (HPBCD) containing media. The proposed new criterion was found to be useful for the rational design of an in vitro diffusion test for transdermal pharmaceuticals.