[Scientific production on the applicability of phenytoin in wound healing]

Histological evaluation of wound healing by topical phenytoin application on extraction socket: an in vivo study in albino Wistar rats

Objective: To investigate the effects of topical phenytoin application on wound healing of extraction socket of albino Wistar rats. Materials and methods: Thirty-six albino Wistar rats were randomly divided into Group A (control), B (1% phenytoin mucoadhesive paste), and C (mucoadhesive paste without phenytoin). All animals were anesthetized followed by first molar extraction. Group A did not receive any agent, whereas, Group B and C received daily application of their respective pastes. Four animals from each group were sacrificed on day 7, 14, and 21 and analyzed histologically. Results: No significant difference was found in blood vessel count among the groups. Statistical increase in percentage of fibroblast in Group B was found as compared with other groups at day 7, whereas, no significant difference was found among groups at day 14. Day 21 showed significant decrease in percentage of fibroblasts in Group B (p-value < 0.001) as compared with Group A and C. Increase in percentage of bone trabeculae in Group B was observed on day 7, 14, and 21 with a significant difference (p-value < 0.05) as compared to Group A and C. Conclusion: Topical application of phenytoin promoted fibroblast proliferation and bone trabeculae formation during healing of extraction socket in rats.

Topical phenytoin administration accelerates the healing of acetic acid-induced colitis in rats: evaluation of transforming growth factor-beta, platelet-derived growth factor, and vascular endothelial growth factor

Ulcerative colitis (UC), limited to the colon's innermost lining, has become a global health problem. Immunomodulatory and monoclonal antibodies are used to treat UC despite their side effects and limitations. Phenytoin is used to heal wounds owing to its effects on growth factors, collagen, and extracellular matrix synthesis. This study aimed to evaluate the effect of topical phenytoin administration in UC. Phenytoin was administered in two doses during the treatment. Eighty male Wistar rats (230-280 g) were divided randomly into ten groups of sham, control, hydrocortisone, phenytoin 1%, and 3% groups in 6- or 12-day treatment protocols. The UC model was induced by the administration of acetic acid 4% into the colon. Animals were killed on the 7th and 13th postoperative days. The main outcome measures included body weight loss, microscopic score, and ulcer index measured using specific criteria. Growth factors were measured by western blotting. Results illustrated that body weight loss was reversed in the treatment groups. Ulcer index had decreased on 6- and 12-day treatment protocols. Microscopic scores in 6-day enema treatment significantly decreased compared to the control groups. Transforming growth factor-beta (TGFβ) significantly increased in a time-dependent manner and platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) significantly increased in a time- and dose-dependent manner in phenytoin 1% and 3% in the 6- and 12-day protocols. Phenytoin dose- and time-dependently reversed weight loss. In addition, histopathological parameters included microscopic scores, and the ulcer index was decreased through the induction of growth factors TGFβ, PDGF, and VEGF and consequently accelerated ulcer healing.

Interference of Lactiplantibacillus plantarum with Pseudomonas aeruginosa on the infected burns in Wistar rats

Burns are the most prevalent type of trauma in the world, and they have a high fatality rate. For cutaneous wound healing, modern and natural therapies, particularly probiotic supplements, have lately been considered. The goal of this study was to see how Lactiplantibacillus plantarum affected wound healing as well as the antibacterial activity of probiotic lactobacilli against Pseudomonas aeruginosa. The glass slide method was used to assess anti-adhesion activity, and the HPLC method was used to quantify anti-adhesion chemicals in cell-free supernatant (CFS). MDR P. aeruginosa was administered subcutaneously directly on the burn after induction of second-degree wounds. Three groups of animals were created. Every day, the supernatants were sprayed for therapy, and the wound healing was monitored. Lactobacilli bacteria had good anti-adhesion effects on P. aeruginosa, according to our findings, and HPLC research revealed that their inhibitory effect could be attributable to four main organic acids: lactic acid, acetic acid, citric acid, and succinic acid. When the effect of treatments on fibroblastic cells was examined, it was discovered that the group treated with L. plantarum supernatants had the most fibroblastic cells when compared to the non-treated group. Furthermore, the bacteria increased the number of fibroblastic cells, re-epithelialization in the wound area, and the thickness of the epidermis and dermis layers. Lactobacilli bacteria's antimicrobial activity against MDR P. aeruginosa was determined by prevents infection. These findings revealed that L. plantarum can treat a P. aeruginosa infection in a second-degree burn and can significantly reduce inflammation.

Update of Topical Interventions for Healing Diabetic Ulcers-A Systematic Review

There are a variety of dressings for wound healing. For this reason, research can assist in the choice and proper use of the intervention. This current view of the effectiveness of dressing on diabetic foot ulcers (DFUs) in patients with type 2 diabetes mellitus. This study is a systematic review of clinical trials selected in 4 databases: PubMed, Scopus, Web of Science, and Cochrane. Studies without language restriction, published between 2009 and 2020, were included. The search resulted in the identification of 5651 articles, of which 58 met all inclusion criteria. Among these, 2 biomaterials (D-acellular dermal matrix and keratinocyte) and phenytoin were highlighted for achieving healing rates of 100% and 95.82% ± 2.22%, respectively. The literature presents several alternatives with different actions, cure rates, reduction rates, and varied cost benefits. The growth in the use of biomaterials for the treatment of DFU can be seen in this study.

Crown Ether Nanovesicles (Crownsomes) Repositioned Phenytoin for Healing of Corneal Ulcers

Drug repositioning is an important drug development strategy as it saves the time and efforts exerted in drug discovery. Since reepithelization of the cornea is a critical problem, we envisioned that the anticonvulsant phenytoin sodium can promote reepithelization of corneal ulcers as it was repurposed for skin wound healing. Herein, our aim is to develop novel crown ether-based nanovesicles "Crownsomes" of phenytoin sodium for ocular delivery with minimal drug-induced irritation and enhanced efficacy owing to "host-guest" properties of crown ethers. Crownsomes were successfully fabricated using span-60 and 18-crown-6 and their size, morphology, polydispersity index, ζ potential, drug loading efficiency, conductivity, and drug release were characterized. Crownsomes exhibited favorable properties such as formation of spherical nanovesicles of 280 ± 18 nm and -26.10 ± 1.21 mV surface charges. Crownsomes depicted a high entrapment efficiency (77 ± 5%) with enhanced and controlled-release pattern of phenytoin sodium. The optimum crownsomes formulation ameliorated ex vivo corneal drug permeability (1.78-fold than drug suspension) through the corneal calcium extraction ability of 18-crown-6. In vivo study was conducted utilizing an alkali-induced corneal injury rabbit model. Clinical and histopathological examination confirmed that crownsomes exhibited better biocompatibility and minimal irritation due to complex formation and drug shielding. Further, they enhanced corneal healing, indicating their effectiveness as a novel drug delivery system for ocular diseases.

Effects of phenytoin spray in prevention of fistula formation following cleft palate repair

BACKGROUND

The effectiveness of topical phenytoin has been reported for the treatment of oral biopsy ulcers, chemotherapy-induced oral mucositis, and chronic periodontitis. This study aimed to investigate the effects of topical phenytoin 2% on the prevention of fistula formation after cleft palate repair.

METHOD

This randomized clinical trial studied patients with nonsyndromic cleft palate who were referred to a tertiary center and underwent cleft palate repair from March 2010 to February 2015. Patients in the phenytoin group received phenytoin spray 2% for 8 weeks and were compared with an age- and sex-matched control group.

RESULTS

A total of 160 patients in two phenytoin and control groups (n = 80 for each group) were recruited to the study. The mean ages of patients in the phenytoin and control groups were 11.42 ± 1.30 and 11.08 ± 1.25 months, respectively. The results showed that six patients (7.5%) in the phenytoin group and 15 patients (18.8%) in the control group formed fistulas during the 6-month follow-up period. There was a significant difference in fistula formation between the phenytoin and control groups (p = 0.035). Furthermore, fistula size was significantly smaller in the phenytoin group compared with the control group (p < 0.001).

CONCLUSION

More frequent use of phenytoin spray can be considered, although there is insufficient information on the long-term side-effects of the chosen drug.

Evidências científicas sobre as úlceras de pernas como sequela da hanseníase

Resumo Objetivo Investigar as evidências científicas sobre as úlceras de pernas como sequela da hanseníase. Métodos Revisão Integrativa da Literatura (RIL). Para identificação do tema e questão de pesquisa, utilizou-se a estratégia PICo, na sequencia procedeu-se a busca nas bases de dados: Index to Nursing and Allied Health Literature (Cinahl), Literatura Latino-americana e do Caribe em Ciências da Saúde (Lilacs), Banco de dados em Enfermagem (BDENF), EMBASE (Elsevier), PUBMED (National Library of Medicine), SCOPUS (Elsevier), Web of Science (Clarivate Analytics), selecionados os descritores específicos para cada uma delas e elaboradas as respectivas estratégias de busca. Os idiomas considerados foram: inglês, português e espanhol. O período da RIL foi indeterminado. Para a seleção dos estudos, utilizou-se a ferramenta Ryyan que permitiu dois dos autores independentemente incluir, excluir, ou ficar indeciso, as discordâncias foram solucionadas por um terceiro. Os artigos selecionados foram classificados de acordo com a Agency for Healthcare Research and Quality (AHRQ). E para a interpretação dos resultados os artigos foram agrupados por semelhança e categorizados da seguinte maneira: autor, ano país, nível de evidência, objetivos e resultados, conclusão e recomendação. Resultados Identificou-se 415 estudos e 10 foram incluídos na revisão. O resultado principal obtido foi o tratamento tópico da úlcera, as vulnerabilidades e os determinantes que assolam os acometidos pela hanseníase não foram estudados. Conclusão Não há fortes evidências sobre as terapias para o tratamento de úlceras de pernas decorrentes da hanseníase que apoiem a diminuição de sequelas incapacitantes ocasionadas pela doença perpetuando o estigma e a desigualdade social.

Topical Application of Teucrium polium Can Improve Wound Healing in Diabetic Rats

Diabetic foot ulcer is one of the major complications among diabetic patients. Several studies have shown that the extract of Teucrium polium (T. polium) is effective in the treatment of diabetic and non-diabetic wounds, as well as burn wounds. The aim of current study was to assess the wound healing activity of T. polium extract ointment in diabetic rats. Sixty-four male Wistar rats were induced diabetes with alloxan injection (125 mg/kg) and surgical wound induced. The rats were divided into 8 groups of eight rats each: control group, eucerin group, phenytoin group, 2%, 3%, 4%, 5% and 10% T. polium groups. The ointment was dressed on the wound twice a day. The process of wound healing was screened by macroscopy and digitalization on days 14 and 21 and until complete wound healing. There was no infection in the wounds of rats in any groups. The process of wounds healing of the 2%, 3%, 4%, 5%, and 10% T. polium ointments, with phenytoin ointment and base ointment (eucerin) on day 14 and 21, showed that the significant difference between the treatment groups with 4% (P = 0.003), 5% (P = 0.001), 10% (P = 0.001) T. polium ointment and phenytoin ointment group (P = 0.001) compared to eucerin group. The results of this study showed that T. polium extract ointment with a 10% ointment accelerates the wound healing process in diabetic rats and is comparable to the phenytoin group.

The impact of topical phenytoin loaded nanostructured lipid carriers in diabetic foot ulceration

OBJECTIVE

The aim of this study is to develop, and characterize nanostructured lipid carriers (NLCs) of phenytoin (PHT) in order to improve its entrapment efficiency and sustained release to improve the healing process.

METHODS

Twenty-seven patients with neuropathic diabetic foot ulceration (DFU) were enrolled in this study. Patients were comparable regarding size, grading of ulcer and control of diabetes with no major deformity. All patients were managed by weekly sharp debridement if indicated and offloaded with cast shoes. They were equally divided into three groups: PHT-NLC-hydrogel (0.5%w/v), phenytoin hydrogel (0.5%w/v) and blank hydrogel groups. Changes in wound area were monitored over 2 months.

RESULTS

Baseline wound area of PHT-NLC, PHT and blank hydrogels were 5.50 ± 3.66, 3.94 ± 1.86 and 5.36 ± 2.14 cm², respectively. Ulcers treated with PHT-NLC hydrogel showed smaller wound area compared to control groups (ρ < 0.05). The overall reduction in ulcer size were 95.82 ± 2.22% for PHT-NLC-hydrogel in comparison to 47.10 ± 4.23% and -34.91 ± 28.33% for PHT and blank-hydrogel (ρ < 0.001), respectively.

CONCLUSION

PHT-NLC hydrogel speeds up the healing process of the DFU without adverse effects when compared to the positive and negative control hydrogels. Moreover, the study can open a window for topical application of NLCs loaded with PHT in the treatment of numerous dermatological disorders that resist conventional treatment.

KEY MESSAGE

The delivery of drug molecules and their localization into the skin is the main purpose of the topical dosage forms. In this manuscript, the impact of topical phenytoin loaded nanostructured lipid carrier in improving wound healing in patients with neuropathic diabetic foot ulceration was investigated. Phenytoin loaded nanostructured lipid carrier dressing was found to be more effective than phenytoin hydrogel at the same concentration in healing of neuropathic diabetic foot ulcer.

Topical phenytoin nanostructured lipid carriers: design and development

Phenytoin (PHT) is an antiepileptic drug that was reported to exhibit high wound healing activity. Nevertheless, its limited solubility, bioavailability, and inefficient distribution during topical administration limit its use. Therefore, this study aims to develop, characterize nanostructured lipid carriers (NLCs), and evaluate their potential in topical delivery of PHT to improve the drug entrapment efficiency and sustained release. The NLCs were prepared by hot homogenization followed by ultra sonication method using 2³ factorial design. NLC formulations were characterized regarding their particle size (PS), zeta potential (ZP), entrapment efficiency percent (%EE), surface morphology, physicochemical stability, and in vitro release studies. The optimized NLC (F7) was further incorporated in 1%w/v carbopol gel and then characterized for appearance, pH, viscosity, stability, and in vitro drug release. The prepared NLCs were spherical in shape and possessed an average PS of 121.4-258.2 nm, ZP of (-15.4)-(-32.2) mV, and 55.24-88.80 %EE. Solid-state characterization revealed that the drug is dispersed in an amorphous state with hydrogen bond interaction between the drug and the NLC components. NLC formulations were found to be stable at 25 °C for six months. The stored F7-hydrogel showed insignificant changes in viscosity and drug content (p>.05) up to six months at 25 °C that pave a way for industrial fabrication of efficient PHT products. In vitro release studies showed a sustained release from NLC up to 48 h at pH 7.4 following non-Fickian Higuchi kinetics model. These promising findings encourage the potential use of phenytoin loaded lipid nanoparticles for future topical application.

Phenytoin: 80 years young, from epilepsy to breast cancer, a remarkable molecule with multiple modes of action

In 1908 phenytoin (5,5-diphenylhydantoin) was first synthesized as a barbiturate derivative in Germany by professor Heinrich Biltz (1865-1943) and subsequently resynthesized by an American chemist of the pharmaceutical company Parke-Davis in 1923 in Detroit. Screening phenytoin did not reveal comparable sedative side effects as barbiturates and, thus, Parke-Davis discarded this compound as a useful drug. In 1936, phenytoin's anticonvulsive properties were identified via a new animal model for convulsive disorders, developed by Putnam and Merritt, who also evaluated its clinical value in a number of patients in the period 1937-1940. For many diseases, mechanism of action of phenytoin remains obscure. The voltage-gated sodium channel was and is generally regarded as the main target to explain phenytoin's activity as an anticonvulsant and an anti-arrhythmic drug. This target, however, does not explain many of the other clinical properties of phenytoin. We will explore a number of original articles on phenytoin published in its 80 years history and give extra attention to the various hypothesis and experiments done to elucidate its mechanisms of action. Phenytoin has been explored in over 100 different disorders; the last two promising indications tested in the clinic are breast cancer and optic neuritis. Most probably, there are multiple targets active for these various disorders, and the insight into which targets are relevant is still very incomplete. It is remarkable that many pharmacological studies tested one dose only, mostly 50 or 100 μM, doses which most probably are higher than the non-plasma bound phenytoin plasma levels obtained during treatment.

Phenytoin silver: a new nanocompound for promoting dermal wound healing via comprehensive pharmacological action

Phenytoin, an antiepileptic drug, has been widely used for wound healing. Inspired by previous studies, phenytoin silver (PnAg), a sparingly soluble silver nanocompound, was synthesized which exhibited good therapeutic efficacy in tissue repair with low toxicity (LD50 >5 g/kg). In vivo studies showed that PnAg could accelerate dermal wound healing and strong inflammation control in Sprague-Dawley rats (SD rat) and Bama minipigs. Due to its low solubility, PnAg led to low toxicity and blood enrichment in animals. Furthermore, PnAg could upregulate the promoter activity of Jak, Stat3, and Stat3 downstream proteins. Therefore, PnAg may serve as an effective therapeutic compound for wound healing through regulating the gp130/Jak/Stat3 signaling pathway.

Re-evaluation of the first phenytoin paste healing effects on oral biopsy ulcers

BACKGROUND

Until now, several formulations of topical phenytoin have been used to promote wound healing.

AIM

This study was aimed at re-evaluating the effects of a newly formulated phenytoin mucoadhesive paste on wound healing after oral biopsy.

SUBJECTS AND METHODS

In a double-blind clinical trial, 35 consecutive patients with oral lichenoid or lichen planus lesions were randomized into two groups. After incisional biopsy, patients applied simple, or 1% phenytoin paste at least three times a day (after each meal), for 4 days. They were evaluated every other day for size of wound closure, severity of pain, and diameter of the inflammatory halo. This study was approved by Medical Ethics committee of Shahid Beheshti University of Medical Sciences, Tehran, Iran. Statistical analysis was performed using Mann-Whitney U test and Ordinal Logistic Regression.

RESULTS

Of 35 patients, 17 (10 [10/17, 59%]) men, 7 (7/17, 41%) women, mean age: 40 (4.11) were in phenytoin group, and 18 (9 [9/9, 50%]) men, 9 (9/9, 50%) women, mean age: 43.1 (5.15) were in placebo group. There were no significant differences between both study groups in terms of age and sex (male/female ratio) (P = 0.76, P = 0.88). As all biopsies were done by means of punch number 8, the incisions were of 10 mm length. After second and third appointments, it was observed that patients in the treatment group showed quicker wound closure and less pain compared to control group significantly (P < 0.05). Although not significant, patients treated with phenytoin paste had smaller inflammatory halo than controls.

CONCLUSION

Applying 1% phenytoin mucoadhesive paste on oral biopsy incisions resulted in accelerated wound healing and decrease in pain.