Dermal Irritation Research Articles

Wound healing activity of herbal ointment containing ethanol leaves extracts of Memecylon species collected from a part of the Eastern Ghats Regions

The study aimed to investigate the wound healing potentiality of a herbal ointment containing the ethanol leaves extract of Memecylon lushingtonii Gamble and Memecylon malabaricum Cogn. Single extracts and combined extracts were formulated into an ointment by using paraffin wax, lanolin, and petroleum jelly. A simple ointment base was used as control and overall compared with the marketed herbal ointment. Initially, dermal index and dermal irritation tests were performed for the extracts separately in rabbits. Then, all the formulations were applied once daily on the Wistar albino rats by excision wound creation. On the 20th day, ointment containing combined extracts showed satisfactory increases in wound contraction (3.14 ± 9.34*** mm2, p < 0.001) when compared with the marketed sample (standard, 6.39 ± 3.18*** mm2, p < 0.001) and control sample (97.72 ± 8.51*** mm2). Thereafter, percent wound closure also revealed a similar trend to the earlier result, where the control sample resulted in 33%, and the combined extract formulation showed 98% as compared to the standard (99%). Thereafter, a significant reduction in epithelialization period resulted from extracts in combination (13.28 ± 0.23**; significant: p < 0.01) than control (21.35 ± 0.14), but the value was a little less than that of standard (15.12 ± 0.20**; significant: p < 0.01 when compared with the control). Overall, the result concluded that the ointment of combined extracts showed satisfactory wound healing due to the presence of many bioactive compounds in the plant extracts especially polyphenolic compounds.

Formulation of Face Serum Combining Pedada Leaf Extract (Sonneratia caseolaris L.) and Kencur Rhizome Extract (Kaempferia galanga L.) As an Antioxidant Cosmetic Preparation

Plants containing natural bioactive compounds with antioxidant activity have the potential to be utilized and formulated into cosmetic products. Pedada (Sonneratia caseolaris L.) leaves, a type of mangrove plant and aromatic ginger (Kaempferia galanga L.) rhizomes are two plants known for their high antioxidant activity. This study aimed to formulate facial serum using a combination of pedada leaves and aromatic ginger rhizome extracts and to evaluate the antioxidant activity of the formulations. The extraction of pedada leaves and aromatic ginger rhizomes was performed using the maceration method with 96% ethanol. Antioxidant activity was determined using the DPPH method. The facial serum was formulated with combinations of pedada leaves and aromatic ginger rhizomes in ratios of 1:1 (F1), 2:1 (F2), and 3:1 (F3). The serum formulations were evaluated for organoleptic properties, homogeneity, pH, viscosity, spreadability, stability, and irritation potential. The results indicated that the IC50 values of pedada leaves and aromatic ginger rhizome extracts were 10.78 ppm and 634.41 ppm, respectively. The best combination was a 3:1 ratio, which yielded an IC50 value of 15.74 ppm. The most effective serum formulation was F2, with an IC50 value of 394.98 ppm. The pH values of serums F0, F2, and F3 were 6.23, 5.72, and 5.43, respectively, and the stability test at 5°C, 28°C, and 40°C for three months showed pH values ranging from 4.5 to 6.5. The viscosity values of serums F0, F2, and F3 were 655, 1810, and 2776 cps, respectively. Acute dermal irritation tests on rabbits indicated that serum formulations F2 and F3 showed no adverse responses

Formulation and evaluation of novel vesicular nanoethosomal patches for transdermal delivery of zidovudine: In vitro, ex vivo, and in vivo pharmacokinetic investigations

Ethosomes are novel soft malleable nanovesicles composed mainly of phospholipids, ethanol (relatively high concentration), glycol, and water. They are used for enhanced drug delivery through the skin. These zidovudine (ZV) vesicles were formulated by cold technique using phospholipids, cholesterol, propylene glycol, and ethanol. The nanoethosomal dispersion was transformed to transethosomal patches using HPMC E15 and chitosan as polymers, a mixture of dichloromethane (DCM) and methanol (1:1 ratio) as solvent, triethyl citrate as plasticizer, and span 80 as permeation enhancer. The physical features of the prepared patches were found to be within acceptable limits. The in vitro study showed drug diffusion of 71.25 − 88.19% through the semipermeable egg membrane in 24 hours. The ex vivo study showed drug permeation of 78.35 − 91.45% through the goat ear membrane in 24 hours. The combination of HPMC and EP4 transdermal patch was determined to be the most effective formulation for transdermal drug administration with sustained drug release, outperforming all other formulations based on acceptable physicochemical parameters, in vitro and ex vivo evaluation studies. Compared with the other formulations, the EP4 formulation had superior penetration kinetics, as proven by its highest permeation co-efficient (2.56 mg/cm2/h), flux (0.494 mg/cm2/h), and enhancement ratio (2.43). Moreover, dermal irritation tests demonstrated that topical therapy did not cause any irritation, indicating its safety. The in vivo bioavailability studies revealed that the AUC showed good bioavailability, which was approximately 188.99 times greater than that of the marketed product. According to the in vitro–in vivo correlation, the ex vivo (in vitro) data can represent physiological conditions that are exact replicas of those found in vivo. Therefore, the ZV transdermal patches exhibit enhanced drug permeation and good bioavailability for better therapeutic outcomes.

Glycyrrhizic Acid-Loaded Poloxamer and HPMC-Based In Situ Forming Gel of Acacia Honey for Improved Wound Dressing: Formulation Optimization and Characterization for Wound Treatment.

The present study aims to formulate a stimuli-responsive in situ hydrogel system to codeliver acacia honey and glycyrrhizic acid for topical application that will aid in absorbing wound exudates, control microbial infestation, and produce angiogenic and antioxidant effects to accelerate wound healing. Therefore, both the natural active constituents were incorporated within an in situ hydrogel composed of poloxamer and hydroxypropyl methylcellulose (HPMC), where the concentrations of the polymers were optimized using Design-Expert software considering optimum values of the dependent variables, gelation temperature (34-37 °C), gelation time (<10 min), and the viscosity (2000-3500 cPs). The optimized formulation showed improved physicochemical properties such as mucoadhesiveness, porosity, swelling, and spreadability, which makes it suitable for wound application. Additionally, the in situ hydrogel exhibited potent in vitro and ex vivo antioxidant effects, in vitro antimicrobial activities, and ex ovo angiogenic effects. Furthermore, the optimized formulation was found to be nontoxic while tested in the HaCaT cell line and acute dermal irritation and corrosion study. The findings of the in vivo wound-healing studies in experimental animal models showed complete wound closure within 15 days of treatment and accelerated development of the extracellular matrix. In addition, the antioxidant, antimicrobial, angiogenic, and wound-healing properties of acacia honey and glycyrrhizic acid coloaded in situ hydrogel were also found to be promising when compared to the standard treatments. Overall, it can be concluded that the optimized stimuli-responsive in situ hydrogel containing two natural compounds could be an alternative to existing topical formulations for acute wounds.

Azelaic acid-based lyotropic liquid crystals gel for acne vulgaris: Formulation optimization, antimicrobial activity and dermatopharmacokinetic study

The proposed study aimed to develop a topical gel containing azelaic acid (AZA)-based lyotropic liquid crystals (LLCs) for the treatment of acne vulgaris. AZA-based LLCs were optimized by varying Poloxamer-407 and polyvinyl alcohol concentration using a central composite design, which showed that both independent variables had a significant effect on the formulation. The highest desirable trial of AZA-based LLCs (Batch-7) containing 300 mg poloxamer-407 and 100 mg polyvinyl alcohol depicted the particle size, zeta potential, and entrapment efficiency of 184.2 nm, −16.1 mV, and 79.96 %, respectively. TEM images confirmed the globular vesicles of LLCs, and ATR-FTIR and DSC results confirmed the compatibility of formulation excipients. In vitro, the release of AZA, AZA-based LLCs, AZA-based LLC gel, and marketed gel showed a release of 23.29, 95.24, 91.07 and 59.88 %, respectively, after 24 h in phosphate buffer pH 6.8. Ex vivo release of AZA-based LLC gel displayed an 86.56 % release after 24 h. The antimicrobial activity of AZA-based LLC gel exhibited a comparable efficacy with marketed gel against Cutibacterium acnes, Staphylococcus epidermis and Staphylococcus aureus. The acute dermal irritation study indicated excellent safety and skin compatibility of AZA-based LLC gel without any erythema and edema. The dermatopharmacokinetic study displayed an enhanced drug retention for AZA-based LLC gel (146.121 ± 21.13 µg/cm2) than marketed gel (58.58 ± 15.95 µg/cm2) in the dermal layer, which would improve its therapeutic effect. These outcomes proved that AZA-based LLC gel has the potential to enhance skin penetration and retention for effective management of acne vulgaris.

Incorporation of Ceragenins into Medical Adhesives and Adhesive Scar Tape to Prevent Microbial Colonization Common in Healthcare-Associated Infections.

Background/Objectives: Healthcare-associated infections involving surgical sites, skin trauma, and devices penetrating the skin are a frequent source of increased expense, hospitalization periods, and adverse outcomes. Medical adhesives are often employed to help protect compromised skin from infection and to secure medical devices, but adhesives can become contaminated by pathogens, exposing wounds, surgical sites, and medical devices to colonization. We aimed to incorporate ceragenins, a class of antimicrobial agents, into silicone- and polyacrylate-based adhesives with the goal of reducing adhesive contamination and subsequent infections. Methods: Three adhesives were developed and evaluated for the release of ceragenins, antimicrobial efficacy, adhesive strength, and dermal irritation. Results: Elution profiles over two weeks showed a high initial release followed by steady, long-term release. Standard microbial challenges of the adhesives by methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, or Candida albicans demonstrated microbial reduction for 6 to 68 days. Lap shear adhesive strength was not reduced for polyacrylate adhesives containing ceragenins, and no dermal irritation was observed in an in vivo model. Conclusions: Ceragenin-containing adhesive materials appear well suited for prevention of bacterial and fungal infections associated with medical devices and bandages.

Dermal toxicity studies of 1,2-benzisothiazolin-3-one (CAS number: 2634-33-5) in Sprague-Dawley rats

Biocides are used as preservatives in various household products, and 1,2-benzisothiazolin-3-one (BIT) is one of the popular chemicals. Therefore, BIT is highly likely to be exposed to human skin, necessitating dermal toxicity evaluation. In this study, we aimed to investigate dermal toxicity, eyes and skin irritation, and skin sensitization of BIT. All studies were conducted according to the Organisation for Economic Co-operation and Development testing guidelines. In acute dermal toxicity using rats, no treatment-related responses were observed at the highest dose (2000 mg/kg). A 28-day repeated dermal toxicity study at 1, 4, and 12 mg/kg/day showed transient local skin irritation lesions, including erythema, exfoliation, and crust formation. Based on no systemic effects, the no observed adverse effect level (NOAEL) of BIT of the 28-day repeated dermal toxicity study was determined to be 12 mg/kg/day. Eye and skin irritation tests showed that BIT is a strong irritant and corrosive to the eyes and a mild irritant to the skin. However, BIT showed no skin sensitization reactions in a local lymph node assay. These dermal toxicity studies can provide valuable information for the risk assessment of BIT.

Highly sensitive and selective rGO-LaFeO3 nanocomposite based formaldehyde sensors towards air quality monitoring

Formaldehyde (HCHO), a ubiquitous volatile organic compound and recognized human carcinogen, is extensively used in industrial applications such as resin and adhesive production. Even minimal exposure to HCHO can induce serious health effects, including respiratory distress and dermal irritation. Thus, the advancement of highly sensitive and selective sensors for HCHO detection is imperative for safeguarding environmental and indoor air quality. Herein, we report the development of a very sensitive, highly selective, and stable HCHO sensor based on reduced graphene oxide (rGO) and lanthanum ferrite (LaFeO3). LaFeO3 and rGO-LaFeO3 nanocomposites with different compositions were synthesized through an affordable and straightforward sol-gel process. Among them, the LFGO(50:1) sensor demonstrated the highest response and selectivity towards HCHO, with a detection limit (theoretically) as low as 19 ppb (1.5 fold). Notably, it exhibited approximately 15-fold p-type response to 1 ppm of HCHO, while operating at 260 °C. The sensor also showed quick response and recovery times of around 1.5 s and 36 s, respectively while having negligible response to other VOCs, including ethanol, methanol, and NH3. A synergistic effect of rGO and LaFeO3 is attributed to this improved sensing behavior. rGO offers a large surface area that facilitates the adsorption of HCHO molecules, while LaFeO3 acts as a catalyst for the oxidation of HCHO. The sensor also showed good selectivity, stability, and reproducibility, making the material a promising candidate for practical applications towards environment monitoring, indoor air quality control, and industrial safety.

Evaluation of Dermal Irritation with the Dextroamphetamine Transdermal System (d-ATS) in Healthy Adults and Patients with ADHD

Evaluation of Dermal Irritation with the Dextroamphetamine Transdermal System (d-ATS) in Healthy Adults and Patients with ADHD

Acute toxicity of antiparasitic selamectin-based drug

The purpose of the research is to evaluate some toxicological parameters of antiparasitic selamectin-based drug.Materials and methods. The study drug is a solution for external use, 1 mL of which contains the active component selamectin (120 mg), as well as additives. The experiments used a total of 66 white outbred male rats, 42 white outbred male mice and 3 guinea pigs. The parameters of acute oral toxicity (in mice and rats), acute dermal toxicity (in rats), and dermal and mucous membrane irritation (in rats and guinea pigs) of antiparasitic selamectin-based drug were evaluated. LD50 was calculated and the irritation of the drug was evaluated using established procedures in toxicology.Results and discussion. The maximum tolerated dose of the selamectin-based drug was 2550 mg/kg in the mice and 4250 mg/kg in the rats. The absolutely lethal dose for the mice and the rats was 6800 and 8500 mg/kg, respectively. It was established that the drug belonged to hazard class 3 (moderately hazardous substances) when administered intragastrically to the animals: LD50 for the mice was 4816.7 mg/kg, and LD50 for the rats was 6091.7 mg/kg. In determining acute dermal toxicity in the rats, the drug was classified as hazard class 4 (low-hazardous substances): LD50 more than 8500 mg/kg. The drug irritant effect on the skin of the rats at doses of 4250, 6375 and 8500 mg/kg was not established. The drug had a mild effect on the mucous membrane of the eyes of the guinea pigs with its recovery to normal within 24 hours.

Reliability and relevance of the ES®-RHE model for in vitro skin irritation test application

IntroductionIn vitro methods have been widely used to assess adverse effects. Reconstructed Human Epidermis (RHE) poses as a fascinating test system employed to assess the dermal irritation hazard potential of chemicals. Although several RHE models are reported in the OECD Test Guideline No. 439, the OECD Document No. 220 encourages the scientific community to develop and validate new RHE test systems due to its relevance for socio-economic advancement. MethodsFollowing the criteria documented in the OECD No. 220, a blind study for skin irritation (OECD 439) was conducted employing the Minimum List of Reference Chemicals for Determination of Reproducibility and Predictive Capacity using ES®-RHE. Structural and functional characteristics were assessed alongside the prediction model. ResultsThe model has shown reproducibility of optical density and barrier function, similarly to internationally validated methods. Furthermore, it shows the cell layers' development and differentiation ability due to Cytokeratin14, Cytokeratin10, and filaggrin expression. The prediction model resulted in sensitivity, specificity and accuracy rates of 100, 70, and 77 %, respectively. ConclusionsThe ES®-RHE demonstrated reliability and relevance, with similar structural and functional characteristics comparable to internationally validated models, in addition to the accepted predictive capacity according to OECD required minimum criteria, thus confirming the suitability of the national ES®-RHE in the hazard prediction of dermal irritation based on OECD Test Guideline No. 439.

Using cephalopod-inspired chemistry to extend long-wavelength ultraviolet and visible light protection of mineral sunscreens.

The emergence of new human and environmental-related toxicity data associated with some common UV filters has catalysed growing interest in the inclusion of boosters and stabilizing ingredients in sunscreens. One approach is to incorporate alternative materials inspired by or mimetic of systems in biology, which offer a notable evolutionary advantage of multifunctionality and stability with increased biocompatibility. We describe the use of a natural product, Xanthochrome® (INCI: Ammonium Xanthommatin), in a series of studies designed to not only assess its safety with marine systems but also its formulation compatibility and function in water-in-oil mineral sunscreens. Xanthochrome is the synthetic form of the naturally occurring chromophore xanthommatin (XA) present in cephalopod skin, which doubles as a photostable antioxidant; however, it has never been explored in combination with mineral UV filters in finished formulations. Given the recent controversies associated with the environmental toxicological effects of some chemicals used in sunscreens, the safety of XA with coral cuttings was first validated at concentrations 5× above those used in our formulations. Next, a particle-based delivery of XA was designed and incorporated into a zinc oxide (ZnO)-based water-in-oil sunscreen, where the SPF, critical wavelength, and visible light (VL) blocking potential were measured. We observed no adverse effects of XA at 100 mg/L when tested with coral cuttings, demonstrating its safety at concentrations exceeding those used in our sunscreens. When formulated with ZnO-based sunscreens, the inclusion of XA increased the total UV absorbance profile by 28% and the total blocking potential of VL by 45%. The formulations also elicited no dermal irritation or sensitization in a human insult repeat patch test (N = 100 subjects). XA is differentiated as a photostable, water-soluble compound that is a VL booster proven safe for skin and coral cuttings. To the best of our knowledge, there are no other boosters that can be classified as such, despite a growing body of literature highlighting the need in the industry.

Evaluation of dermal and ocular safety of natural products based on Murraya paniculata, Eucalyptus sp. and Indigofera suffruticosa Mill. in New Zealand rabbits

This study was conducted to evaluate the acute dermal and ocular irritant potential of three natural products obtained from medicinal plants Murraya paniculata (PNI), Eucalyptus sp. (PNII), and Indigofera suffruticosa Mill. (PNIII) for topical use in veterinary medicine. For the assessment of acute dermal and ocular irritability, methodologies from the Organization for Economic Cooperation and Development (OECD) were employed through guidelines 404 and 405, respectively, using New Zealand albino rabbits. The evaluated products showed no signs or symptoms of irritation/corrosion on the skin and eyes, exhibiting dermal and ocular irritation indices within the range of classification of non-irritating substances, according to the OECD Harmonized Integrated Classification System.

Acute dermal irritation and skin sensitization study of mesoporous antibacterial bioactive glass microsphere impregnated surgical cotton gauze dressing material on rabbits and guinea pigs

Acute dermal irritation and skin sensitization study of mesoporous antibacterial bioactive glass microsphere impregnated surgical cotton gauze dressing material on rabbits and guinea pigs

Therapeutic potential of limonene-based syringic acid nanoemulsion: Enhanced ex-vivo cutaneous deposition and clinical anti-psoriatic efficacy

Nanoemulsions have carved their position in topical delivery owing to their peculiar features of forming a uniform film on the skin and conquering stratum corneum barrier and hence fostering dermal penetration and retention. The present work developed syringic acid nanoemulsion (SA-NE) by spontaneous emulsification as an anti-psoriatic remedy via the dermal route. SA-NE were prepared with either lauroglycol90, limonene or their combination (oil phase) and tween80 (surfactant) with variable concentrations. The physicochemical characteristics of SA-NE were assessed together with Ex-vivo skin deposition and dermal toxicity. The effectiveness of optimal formula in psoriatic animal model and psoriatic patients was investigated using PASI scoring and dermoscope examination. Results showed that, SA-NE containing mixture of lauroglycol 90, limonene and 10 % tween80 (F5), was selected as the optimal formula presenting stable nanoemulsion for 2-month period, showing droplet size of 177.6 ± 13.23 nm, polydispersity index of 0.16 ± 0.06, zeta potential of −21.23 ± 0.41 mV. High SA% in different skin strata and no dermal irritation was noticed with limonene-based SA-NE also it showed high in-vitro anti- inflammatory potential compared to the blank and control formulations. A preclinical study demonstrated that limonene-based SA-NE is effective in alleviating psoriasis-like skin lesions against imiquimod-induced psoriasis in rats. Clinically, promising anti-psoriatic potential was asserted as all patients receiving F5 experienced better clinical improvement and response to therapy, achieving ≥ 50 % reduction in PASI scores versus only 35 % responders in the Dermovate® cream group. Collectively, the practical feasibility of limonene-based SA-NE topical delivery can boost curative functionality in the treatment of psoriatic lesions.

Bis-(2-Chloroisopropyl) ether.

Bis-(2-Chloroisopropyl) ether (BCIPE) was used as a solvent for fats, greases, paint, varnish removers, and in spotting and cleaning solutions. However, BCIPE has not been commercially manufactured or used for numerous years. In experimental animal studies, BCIPE is moderately toxic following acute oral, dermal, and inhalation routes of exposure. BCIPE is a severe eye irritant but not a dermal irritant or dermal sensitizer. BCIPE was not genotoxic or mutagenic in in vitro and in vivo assays; it was not toxic in a 3-generation reproductive dietary study in rats. Short-term, repeated inhalation and oral exposure in rats produced increased liver and kidney weights and congestion; dermal exposure in rabbits did not produce any observable adverse effects. BCIPE did not produce a statistically significant increase in tumors in two different 2-year dietary studies in mice and rats. In mice, technical grade BCIPE produced increased incidences of alveolar/bronchiolar adenomas in females, hepatocellular carcinomas in males, and a low incidence of forestomach hyperplasia (in both sexes at the high-dose). Further investigation with technical grade BCIPE concluded that these effects were species- and dose-specific with limited, if any, relevance to humans. The NOAEL of 400 ppm (15 mg/kg/day) from the 2-year dietary study in female rats was considered the point of departure for the health-based WEEL derivation. After adjustment for duration of exposure, interindividual variability, and intraindividual variability, an 8-h time-weighted average (TWA) WEEL value of 3 ppm (21 mg/m3) was derived. This exposure limit is expected to provide a significant margin of safety against any potential adverse health effects in workers.

ASSESSMENT OF DERMAL IRRITATION OF LAO NHA QUE COCONUT OIL IN EXPERIMENTAL ANIMALS

Lao Nha Que virgin coconut oil (LNQ VCO) is a natural product inteneded to treat some skin diseases such as burns, atopic dermatitis, and xerosis.... To provide information on its local irritation, this study was carried out to evaluate the dermal irritation of LNQ VCO. 0.5 ml of VCO was applied on the skin in one side of the spine while 0.5 ml of distilled water was applied on the other side. After 4-hour exposure period, the residual LNQ VCO was removed and the skin reactions for erythema and oedema was described and scored at 1 hour, 24 hours, 48 hours and 72 hours after removing the patches. The results showed that the erythema appeard on the LNQ VCO-applied skin in two out of three rabbits and recovered up to 72h. The primary irritation index was calculated to catogorize the skin irritation of LNQ VCO. The primary irritation index of LNQ VCO was 0.78. Thus, LNQ VCO might cause slight irritation on the rabbit’s skin.

Assessment of the feed additive consisting of Patent Blue V for all non-food-producing animal species for the renewal of its authorisation (Versele-Laga NV).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of Patent Blue V as a sensory feed additive for non-food-producing animals. The additive is already authorised for use with non-food-producing animals. The applicant has not provided evidence that the additive currently on the market complies with the existing conditions of authorisation. The FEEDAP Panel cannot conclude whether the additive remains safe for the target species due to the non-compliance with the specifications and the lack of adequate data on the potential aneugenicity of the additive. In the absence of data, the FEEDAP Panel cannot conclude on the potential of the additive to be a dermal and eye irritant nor a dermal and respiratory sensitiser. Since the potential genotoxicity of the additive was not ruled out, the exposure to the additive of the unprotected users should be minimised. The Panel retains that the previously made conclusion on the efficacy remains valid.

Safety and efficacy of a feed additive consisting of inactivated selenised yeast (Saccharomyces cerevisiaeCCTCC M 2022402) for all animal species (Phytobiotics Futterzusatzstoffe GmbH).

Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of the selenised yeast (inactivated) Saccharomyces cerevisiae CCTCC M 2022402 (Plexomin® Se 3000, available in two forms: 'granules' and 'micro') as a nutritional feed additive for all animal species. Based on a tolerance-efficacy trial, the FEEDAP Panel concluded that the additive is safe for chickens for fattening at proposed conditions of use and this conclusion can be extrapolated to all animal species. In the absence of deposition data in all animal species and products, the FEEDAP Panel cannot conclude on the safety for the consumer. Plexomin® Se 3000 (granules) is dust-free; therefore, the exposure through inhalation is unlikely. Plexomin® Se 3000 (micro) presents a risk by inhalation. Both forms of the additive (granules and micro) are considered as respiratory sensitisers. Due to the lack of data, no conclusions can be drawn on the dermal and eye irritation potential of Plexomin® Se 3000 (granules). Plexomin® Se 3000 (micro) is not irritant to the skin and the eyes. No conclusions can be drawn on the potential of both forms of the additive to be dermal sensitisers. The use of the additive in animal nutrition is considered safe for the environment. The additive is an efficacious source of selenium in feedingstuffs for all animal species.

Development of PU foam dressings loaded with extract of Plectranthus amboinicus for burn wound healing

Objective To develop Plectranthus amboinicus extract loaded Polyurethane foam dressing for burn wound healing. Significance Plectranthus amboinicus is traditionally used as an anti-inflammatory and wound-healing agent. Its incorporation in a PU foam dressing will offer the dual benefits of foam dressing as well as the healing potential of P. amboinicus. Methods PU foam dressings were prepared and loaded with P. ambionicus leaf extract (PAE). The dressings were prepared with varying concentrations (0.5–2%) of extract along with Toluene diisocyanate, polypropylene glycol (PPG), and liquid paraffin. The dressings were characterized by Scanning Electron Microscopy and evaluated for Moisture Vapor Transmission Rate, absorption rate, porosity, and mechanical strength followed by in vivo burn wound-healing studies in comparison to a marketed dressing. Results The MVTR was found to be optimum in formulations FD2-FD4 with values ranging from 2068.06 ± 0.99 to 2095.00 ± 0.25 g/m2/day. Absorption rate was found to be between 1.27 ± 0.01, 1.31 ± 0.00, and 1.30 ± 0.02 g/cm2 for formulations FD2-FD4. Formulations FD1, FD2, FD3, FD4 showed better porosity when compared to other formulations. Formulation FD4 was further characterized by micro-CT and a porosity of 46.32% was obtained. Tensile strength measurement indicated that the selected formulations were flexible enough to withstand regular handling during dressing changes. Acute dermal irritation performed on rabbits showed no irritation, erythema, eschar, and edema. In vivo wound-healing studies performed on albino wistar rats showed that the FD4 formulation has better wound healing property. Conclusion Plectranthus ambionicus-loaded PU foam dressing demonstrated promising burn wound-healing potential