Evaluation of dermal irritation and skin sensitization due to vitacoxib

Preparing a novel baicalin-loaded microemulsion-based gel for transdermal delivery and testing its anti-gout effect

We previously demonstrated that baicalin had efficacy against gouty arthritis (GA) by oral administration. In this paper, a novel baicalin-loaded microemulsion-based gel (B-MEG) was prepared and assessed for the transdermal delivery of baicalin against GA. The preparation method and transdermal capability of B-MEG was screened and optimized using the central composite design, Franz diffusion cell experiments, and the split-split plot design. Skin irritation tests were performed in guinea pigs. The anti-gout effects were evaluated using mice. The optimized B-MEG comprised of 50 % pH 7.4 phosphate buffered saline, 4.48 % ethyl oleate, 31.64 % tween 80, 13.88 % glycerin, 2 % borneol, 0.5 % clove oil and 0.5 % xanthan gum, with a baicalin content of (10.42 ± 0.08) mg/g and particle size of (15.71 ± 0.41) nm. After 12 h, the cumulative amount of baicalin permeated from B-MEG was (672.14 ± 44.11) μg·cm-2. No significant skin irritation was observed following B-MEG application. Compared to the model group, B-MEG groups significantly decreased the rate of auricular swelling (P < 0.01) and number of twists observed in mice (P < 0.01); and also reduced the rate of paw swelling (P < 0.01) and inflammatory cell infiltration in a mouse model of GA. In conclusion, B-MEG represents a promising transdermal carrier for baicalin delivery and can be used as a potential therapy for GA.

Fabrication and in vitro characterization of curcumin film-forming topical spray: An integrated approach for enhanced patient comfort and efficacy

Background

Curcumin, known for its anti-inflammatory properties, was selected for the developing consumer friendly film forming spray that offers precise delivery of curcumin and and improves patient adherence.

Methods

An optimized film-forming solution was prepared by dissolving curcumin (1%), Eudragit RLPO (5%), propylene glycol (1%), and camphor (0.5%) in ethanol: acetone (20:80) as the solvent. The solution was filled in a spray container which contained 70% solutions and 30% petroleum gas. In-vitro characterization was performed.

Results

Potential anti-inflammatory phytoconstituents were extracted from the PubChem database and prepared as ligands, along with receptor molecules (nsp10-nsp16), for molecular docking using Autodock Vina. The docking study showed the lowest binding energy of -8.2 kcal/mol indicates better binding affinities. The optimized formulation consisted of ethanol:acetone (20:80) as the solvent, Eudragit RLPO (5%) as the polymer, propylene glycol (1%) as the plasticizer, and camphor oil (0.5%) as the penetration enhancer. The optimized formulation exhibited pH of 5.8 ± 0.01, low viscosity, low film formation time (19.54 ± 0.78 sec), high drug content (8.243 ± 0.43 mg/mL), and extended ex vivo drug permeation (85.08 ± 0.09%) for nine hours. Consequently, the formulation was incorporated into a container using 30% liquefied petroleum gas, delivering 0.293 ± 0.08 mL per actuation, containing 1.53 ± 0.07 mg of the drug. The film-forming spray exhibited higher cumulative drug permeation (83.94 ± 0.34%) than the marketed cream formulation and pure drug solution after 9 h, with an enhancement ratio of 14. Notably, the film-forming spray exhibited no skin irritation and remained stable for over three months.

Conclusions

The developed curcumin film-forming system is promising as a carrier for wound management because of its convenient administration and transport attributes. Further in vivo studies are required to validate its efficacy in wound management.

Effect of glycerol and dibutyl phthalate on modified natural rubber latex based drug delivery systems

The work highlights the impact of the incorporation of two pharmaceutical plasticizers viz.; glycerol (GLY; hydrophilic) and dibutyl phthalate (DBP; hydrophobic) on the controlled drug release features of a deproteinised natural rubber latex (DNRL) -based matrix. The effects of the plasticizers on the mechanical properties, glass transition temperature (T_g), water absorption behaviour and porosity of DNRL have been initially investigated. The plasticized membranes have been found to show a hemolysis percentage (HP) of <5 %; confirming its compatibility with human blood. The potential of the modified DNRL membranes to function as drug carriers have been examined with metformin hydrochloride (MET) as a model drug.

Euphorbia neriifolia (Indian Spurge Tree): A Plant of Multiple Biological and Pharmacological Activities

Although India has a well-established and growing economy surrounding synthetic drug chemistry with an antibiotic base, a large part of the population, especially in forested villages and tribal belts, is relying solely on plant-derived drugs. This is due to a lower number of side effects, low chances of resistance development against pathogenic microorganisms, as well as the diversity and affordability of such drugs. In the Indian subcontinents, Euphorbia neriifolia Linn. (EN) is one of the valuable plants from the big family of Euphorbiaceae, which is usually found in rocky and hilly areas. E. neriifolia was found to be useful in curing tumors, abdominal swelling, bronchial infection, hydrophobia, earache, cough and cold, asthma, leprosy, gonorrhea, spleen enlargement, leucoderma, snake bites, scorpion stings, and causing appetite improvement, etc. Different in vitro and in vivo experimental studies were performed to determine the antioxidant, anti-diabetic, immunomodulatory, anti-inflammatory, anti-arthritic, wound healing, anti-atherosclerosis, radioprotective, anti-anxiety, anti-convulsant, anti-psychotic, anti-thrombotic, dermal irritation, hemolytic, analgesic, anti-fertility, diuretic, anti-microbial, anti-diarrheal, and anti-carcinogenic activities of the various parts of EN. Several bioactive compounds, such as euphol, nerifoliol, taraxerol, euphonerins A–G, lectin, etc., were isolated from E. neriifolia and need to be investigated further for various biological activities (cardiovascular and neuronal diseases). In the pharmaceutical sector, E. neriifolia was selected for the development of new drugs due to its broad pharmacological activities. Therefore, in the present review, distribution, classification, morphological and microscopical description, phytochemical investigation, pharmacological activities, medicinal uses, harmful effects, and their treatment were evaluated, especially against different lifestyle-related diseases.

Wound Healing and Anti-Inflammatory Effects of a Newly Developed Ointment Containing Jujube Leaves Extract

Ziziphus jujuba Mill. (jujube) is a well-known medicinal plant with pronounced wound healing properties. The present study aimed to establish the chemical composition of the lyophilized ethanolic extract from Romanian Ziziphus jujuba leaves and to evaluate the healing and anti-inflammatory properties of a newly developed lipophilic ointment containing 10% dried jujube leaves extract. The ultra-High-Performance Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry method was used, and 47 compounds were detected, among them the novel epicatechin and caffeic acid. The extract contains significant amounts of rutin (29.836 mg/g), quercetin (15.180 mg/g) and chlorogenic acid (350.96 µg/g). The lipophilic ointment has a slightly tolerable pH, between 5.41-5.42, and proved to be non-toxic in acute dermal irritation tests on New Zealand albino rabbits and after repeated administration on Wistar rats. The ointment also has a healing activity comparable to Cicatrizin (a pharmaceutical marketed product) on Wistar rats and a moderate anti-inflammatory action compared to the control group, but statistically insignificant compared to indomethacin in the rat-induced inflammation test by intraplantar administration of kaolin. The healing and anti-inflammatory properties of the tested ointment are due to phenolic acids and flavonoids content, less because of minor components as apocynin, scopoletin, and isofraxidin.

A combination of linalool and linalyl acetate synergistically alleviates imiquimod-induced psoriasis-like skin inflammation in BALB/c mice

Introduction: Psoriasis is a chronic inflammatory skin disorder characterized by keratinocyte hyperproliferation and differentiation with increased immune cell infiltration. The anti-psoriatic effect of lavender oil has been reported. However, its phytoconstituents, linalool (L) and linalyl acetate (LA), showed a distinctive affinity with psoriasis targets.

Objectives: This investigation was aimed to determine the combined effect of L and LA in ameliorating psoriasis-like skin inflammation and its safety in long-term topical uses.

Methods: The combined effect of L and LA was compared with their individual effects. The anti-psoriatic activity was performed using imiquimod (IMQ)-induced psoriasis in BALB/c mice and evaluated to reduce PASI and CosCam scores and Th-1 and Th-17 cell-specific cytokine levels. The acute and repeated dose dermal toxicities were investigated as per the OECD guidelines.

Results: L and LA combination (LLA) in the 1:1 w/w ratio at 2% concentration showed a synergistic effect. The combination showed 76.31% and 71.29% recovery in PASI and CosCam Scores; however, L2% and LA2% showed 64.28% and 47.61% recovery in PASI and 64.75 and 56.76% recovery in CosCam scores, respectively. It showed >90% and >100% recovery in Th-17 and Th-1 cell-specific cytokines, respectively, and restored epidermal hyperplasia and parakeratosis toward normal compared with psoriatic mice. A marked reduction in NF-κB, cck6, and the IL-17 expression was also observed in the LLA-treated group. This combination was safe in a therapeutically effective dose for 28 days as no significant changes were observed in organ and body weights, liver and kidney parameters, and differential leukocyte counts.

Conclusion: This study proves the synergy between L and LA in a 1:1 w/w ratio at 2% in the treatment of psoriasis-like skin inflammation and provides strong scientific evidence for its safe topical use.

Evaluation of the dermal irritation and skin sensitization due to thiocolchicoside transdermal drug delivery system

The skin irritation and sensitization potential of the new transdermal patch of the Thiocolchicoside formulated with Dura 87-6908 was evaluated on the rabbits and guinea pig as per the standard guidelines of OECD. Skin irritation test was performed on the rabbits by applying the placebo patch for 72 hours and dermal reactions like edema, erythema were noted. No clinical signs or dermal reactions were observed in the rabbits. Sensitization potential was measure on the guinea pig and animal was challenged to transdermal therapeutic system of the Thiocolchicoside, negative control group while group exposed to CDNB produced the sensitization reactions. These findings proved that Thiocolchicoside does not produce any dermal toxicity, irritation and sensitization and hence it is safe for dermal use.

Pharmacokinetics, Tissue Distribution, Metabolism and Excretion of a Novel COX-2 Inhibitor, Vitacoxib, in Rats

The objectives of this study were to elucidate absorption, tissue distribution, excretion, and metabolism of vitacoxib, a novel selective cyclooxygenase-2 inhibitor, in Wistar rats. Vitacoxib was detected in most tissues within 15 min, suggesting that it was well distributed. Moreover, it could cross the intestinal barrier. Vitacoxib was mainly eliminated as two metabolites. Nine proposed metabolites of vitacoxib were found in the plasma, bile, urine, and feces of rats. Two main metabolites, 4-(4-chloro-1-(5-(methyl-sulfonyl) pyridin-2-yl)-1H-imidazol-5-yl) phenyl methanol (M1) and 4-(4-chloro-1-(5-(methyl-sulfonyl) pyridin-2-yl)-1H-imidazol-5-yl) benzoic acid (M2), were identified in rat feces and urine. Further, the authentic standards of M1 and M2 were synthesized to confirm their structures. The carboxylic acid derivative was the major metabolite of vitacoxib excreted in the urine and feces. Hydroxylation of the aromatic methyl group of vitacoxib and additional oxidation of the hydroxymethyl metabolite to a carboxylic acid metabolite were the proposed metabolic pathways. Vitacoxib displayed a high AUC_last (4895.73 ± 604.34 ng·h/ml), long half-life (4.25 ± 0.30 h), slow absorption (T_max, 5.00 ± 2.00 h), and wide tissue distribution in rats. Our findings provide significant information for the further development and investigation of vitacoxib as an effective nonsteroidal anti-inflammatory agent, and highly its potential for use future in a clinical setting.

The effect of combination of functional and nonfunctional acrylic polymers on transdermal patches of : in vitro permeation, in vivo evaluation using biochemical parameters, and stability studies

Background

A double-layer transdermal drug-in-adhesive patch of carvedilol was developed using functional and nonfunctional grades of acrylic adhesives, DURO-TAK® 387-2051, DURO-TAK® 387-2510, and DURO-TAK® 87-4098. The patch was designed to provide adequate permeation of the drug up to 2 days, with effective adhesion attributes. An optimized formulation was selected, the effect of the combination was studied and a 180° peel strength test was performed to evaluate adhesive properties. Further, the patch was assessed for in vivo studies on basis of biochemical parameters, skin irritation, and stability studies. The stability study was carried out on optimized fresh (S1) and 6 months old patches stored at room, and accelerated condition (40 ± 2 °C/75 ± 5% RH) using FTIR, DSC, and SEM techniques.

Result

It was studied that the steady-state flux (Jss) or permeation rate of the drug through excised rat skin has relied on the nature of acrylic and the combination of acrylic polymers. The TDDS containing –OH functional group DT 387-2510 with nonfunctional pressure-sensitive adhesives (PSAs) DT 87-4098, with Span 80 as penetration enhancer exhibited maximum flux (19.12 ± 0.64 μg/cm2/h) and form homogeneous and stable blends, controlling permeation of drug at a desired steady rate for 48 h. The data obtained from in vivo studies using biochemical parameters suggested that there were no statistical differences observed in results for the control and treated group while analyzing observations for serum creatinine, glucose test, sodium test, albumin, and potassium (p > 0.05). Also, the optimized formulation showed no sign of localized reactions and was confirmed by a skin histological study indicating the formulation was safe and compatible with the skin. A significant shift of peaks was not observed in FTIR spectra and DSC thermograms of the patches after the stability period.

Conclusion

The investigation reveals that the drug-in-adhesive patch of carvedilol, by a combination of functional and nonfunctional PSAs, provides a good and effective option for controlled delivery of carvedilol. From our findings, it has been concluded that drug in the adhesive patch has been able to provide satisfactory adhesion, drug uniformity, drug permeation, marked positive biochemical results, and good stability.

Nanobioremediation: A sustainable approach towards the degradation of sodium dodecyl sulfate in the environment and simulated conditions

Nanotechnology has gained huge importance in the field of environmental clean-up today. Due to their remarkable and unique properties, it has shown potential application for the remediation of several pesticides and textile dyes. Recently it has shown positive results for the remediation of sodium dodecyl sulfate (SDS). One of the highly exploited surfactants in detergent preparation is anionic surfactants. The SDS selected for the present study is an example of anionic linear alkyl sulfate. It is utilized extensively in industrial washing, which results in the high effluent level of this contaminant and ubiquitously toxic to the environment. The present review is based on the research depicting the adverse effects of SDS in general and possible strategies to minimizing its effects by bacterial degradation which are capable of exploiting the SDS as an only source of carbon. Moreover, it has also highlighted that how nanotechnology can play a role in the remediation of such recalcitrant pesticides.

Permeation, stability and acute dermal irritation of miroestrol and deoxymiroestrol from Pueraria candollei var. mirifica crude extract loaded transdermal gels

In this study, permeation behaviors and chemical stability of miroestrol and deoxymiroestrol from Pueraria candollei var. mirifica (PM), Thai traditional medicine, crude extract containing transdermal gels were firstly evaluated. Three different PM extract containing gels were formulated, including hydroalcoholic and microemulsion gels using carbomer, and silicone gel using silicone elastomer. In vitro permeation through porcine ear skin demonstrated that the flux and 24 h cumulative permeation of miroestrol and deoxymiroestrol were in the order of hydroalcoholic > silicone > microemulsion gels. Hydroalcoholic gel provided the highest partition coefficient from gel onto skin, and thus the skin permeability coefficient. After 24 h permeation, no miroestrol and deoxymiroestrol remained deposited in the skin. Accelerated study using heating-cooling revealed insignificant difference between the remaining percentages of miroestrol and deoxymiroestrol in aqueous and non-aqueous based gels. Long-term stability study showed that miroestrol contents remained constant for 90 d and 30 d under 5 ± 3 °C and 30 ± 2 °C, 75 ± 5%RH, respectively; whereas the percentage of deoxymiroestrol decreased significantly after 30 d storage, irrespective of storage conditions. Acute dermal irritation test on New Zealand White rabbits showed that PM hydroalcoholic gels were non-irritant, with no signs of erythema or oedema.[Figure: see text].

Optimization of the extraction conditions and dermal toxicity of oil body fused with acidic fibroblast growth factor (OLAF)

INTRODUCTION

Oil body (OB), a subcellular organelle that stores oil in plant seeds, is considered a new transdermal drug delivery system. With the increasing understanding of the OB and its main protein (oleosin), numerous studies have been conducted on OB as "carrier" for the expression of exogenous proteins. In our previous study, oil body fused with aFGF (OLAF) was obtained using a plant oil body expression system that had been preliminarily proven to be effective in accelerating the healing of skin wounds. However, no dermal toxicological information on OLAF is available.

OBJECTIVE

To ensure the dermal safety of OLAF, a series of tests (the acute dermal toxicity test, 21-day repeat dermal toxicity test, dermal irritation test and skin sensitisation test) were conducted after optimising the extraction protocol of OLAF.

MATERIALS AND METHODS

To improve the extraction rate of OLAF, response surface methodology (RSM) was first employed to optimise the extraction conditions. Then, Wistar rats were exposed to OLAF (400 mg·kg^-1 body weight) in two different ways (6 hours/time for 24 hours and 1 time/day for 21 days) to evaluate the acute dermal toxicity and 21-day repeated dermal toxicity of OLAF. In the acute dermal toxicity test, clinical observations were conducted to evaluate the toxicity, behaviour, and health of the animals for 14 consecutive days. Similarly, the clinical signs, body weight, haematological and biochemical parameters, histopathological changes and other indicators were also detected during the 21 days administration. For the dermal irritation test, single and multiple doses of OLAF (125 mg·kg^-1 body weight) were administered to albino rabbits for 14 days (1 time/day). The irritation reaction on the skin of each albino rabbit was recorded and scored. Meanwhile, skin sensitisation to OLAF was conducted using guinea pigs for a period of 28 days.

RESULTS

Suitable extraction conditions for OLAF (PBS concentration 0.01, pH of PBS 8.6, solid-liquid ratio 1:385 g·mL^-1) were obtained using RSM. Under these conditions, the extraction rate and particle size of OLAF were 7.29% and 1290 nm, respectively. In the tests of acute dermal toxicity and 21-day repeated dermal toxicity, no mortality or significant differences were observed in terms of clinical signs, body weight, haematological parameters, biochemical parameters and anatomopathological analysis. With respect to the dermal irritation test and skin sensitisation test, no differences in erythema, oedema or other abnormalities were observed between treatment and control groups on gross and histopathological examinations.

CONCLUSIONS

The results of this study suggest that OLAF does not cause obvious toxicity, skin sensitisation or irritation in animals.

Acute Wound Healing Potential of Marine Worm, Diopatra claparedii Grube, 1878 Aqueous Extract on Sprague Dawley Rats

Diopatra claparedii which is colloquially known as Ruat Sarung can be found along the west coast of Peninsular Malaysia. The species has a unique ability to regenerate anterior and posterior segments upon self-amputation or injury, thus having potential as a wound healing promoter. In this study, the wound healing potential of D. claparedii aqueous extract on acute wound model in rats was revealed for the first time. Various concentrations (0.1%, 0.5%, and 1.0% w/w) of D. claparedii ointment were formulated and tested on Sprague Dawley rats through topical application on full-thickness skin wounds for 14 days. The wound healing effects were investigated via behaviour observation, wound contraction, and histopathological analysis. Quality assessment was performed via skin irritation test, microbial contamination test (MCT), and heavy metal detection. The study also included test for antibacterial activities and detection of bioactive compounds in D. claparedii. One percent of D. claparedii ointment showed rapid wound healing potential with good soothing effects and more collagen deposition in comparison to the commercial wound healing ointments such as acriflavine (0.1% w/v) and traditional ointment gamat (sea cucumber extract) (15.0% w/v). No local skin irritation, microbial contamination, and insignificant concentration of heavy metals were observed, which indicate its safe application. Moreover, the aqueous extract of D. claparedii exhibited antibacterial activities against Escherichia coli and Pseudomonas aeruginosa with minimum inhibitory concentration (MIC) value at 0.4 g/ml. ¹H NMR analysis of the aqueous extract of D. claparedii revealed some metabolites that might be responsible for its wound healing properties such as amino acids, halogenated aromatics, organic acids, vitamins, and others. Altogether, these results suggested that the aqueous extract of D. claparedii could be utilised as an alternative natural wound healing promoter.

New Delivery Route of Gambogic Acid Via Skin for Topical Targeted Therapy of Cutaneous Melanoma and Reduction of Systemic Toxicity

Cutaneous melanoma is the deadliest form of skin cancer, and gambogic acid (GA) exhibits potent anti-melanoma activity. However, clinical application of GA via intravenous injection and oral administration is limited by systemic toxicity and rapid metabolism in the blood. Here, we developed a new, topical route of GA delivery for anti-melanoma activity and reduction of systemic toxicity. The results indicated that the barrier of the stratum corneum (SC) and low diffusion of GA in the hydrophilic viable skin (epidermis and dermis) limited the GA penetration through intact skin. The combination of azone (AZ) and propylene glycol (PG) showed obvious synergistic effects on skin penetration by GA via improving the permeability of the SC and greatly increasing the skin accumulation of GA, thereby forming a high drug concentration in the skin and achieving a topical targeted treatment of melanoma. In addition, GA (AZ-PG) achieved the same anti-melanoma effect via topical delivery as via intravenous injection. Intravenous injection and oral administration of GA induced remarkable pathological changes in various organs in mice, whereas GA was not toxic to various organs or to the skin via topical delivery. These findings indicated that topical administration of GA is an alternative route for melanoma treatment.

Non-Linear Mixed-Effects Pharmacokinetic Modeling of the Novel COX-2 Selective Inhibitor Vitacoxib in Cats

The objective of this study was to develop a non-linear mixed-effects (NLME) model to describe the disposition kinetics of vitacoxib in cats following intravenous (I.V) and oral (P.O) (single and multiple) dosing. Data from six consecutive studies with 16 healthy neutered domestic short hair cats were pooled together to build a pharmacokinetic (PK) model using NLME. Population PK parameters were estimated using the stochastic approximation expectation maximization (SAEM) algorithm implemented in Monolix 2019R2. A two-compartment mammillary disposition model with simultaneous zero- and first-order absorption best described the PK of vitacoxib in plasma after oral dosing. The systemic CL of vitacoxib was found to be low (110 ml/h), with a steady-state volume of distribution (VSS) of 3.42 L in cats. Results from the automated covariate search in Monolix 2019R2 showed that bodyweight had a significant effect on the central volume of distribution of vitacoxib. Lastly, using Monte Carlo simulations, we investigated the time course of several dosages of vitacoxib from 0.01 to 8 mg/kg. Using this simulation set, we found a range of reasonable dosages that produce therapeutic plasma concentrations of vitacoxib for 24 h or more in cats.

Advances in selecting appropriate non-rodent species for regulatory toxicology research: Policy, ethical, and experimental considerations

In vivo animal studies are required by regulatory agencies to investigate drug safety before clinical trials. In this review, we summarize the process of selecting a relevant non-rodent species for preclinical studies. The dog is the primary, default non-rodent used in toxicology studies with multiple scientific advantages, including adequate background data and availability. Rabbit has many regulatory advantages as the first non-rodent for the evaluation of reproductive and developmental as well as local toxicity. Recently, minipigs have increasingly replaced dogs and rabbits in toxicology studies due to ethical and scientific advantages including similarity to humans and breeding habits. When these species are not relevant, nonhuman primates (NHPs) can be used as the available animal models, especially in toxicology studies investigating biotherapeutics. Particularly, based on the phylogenetic relationships, the use of New-World marmosets can be considered before Old-World monkeys, especially cynomolgus with robust historical data. Importantly, the use of NHPs should be justified in terms of scientific benefits considering target affinity, expression pattern, and pharmacological cross-reactivity. Strict standards are required for the use of animals. Therefore, this review is helpful for the selection of appropriate non-rodent in regulatory toxicology studies by providing sufficient regulatory, ethical, and scientific data for each species.

Pharmacokinetics of three formulations of vitacoxib in horses

The pharmacokinetic properties of three formulations of vitacoxib were investigated in horses. To describe plasma concentrations and characterize the pharmacokinetics, 6 healthy adult Chinese Mongolian horses were administered a single dose of 0.1 mg/kg bodyweight intravenous (i.v.), oral paste, or oral tablet vitacoxib in a 3-way, randomized, parallel design. Blood samples were collected prior to and at various times up to 72 hr postadministration. Plasma vitacoxib concentrations were quantified using UPLC-MS/MS, and pharmacokinetic parameters were calculated using noncompartmental analysis. No complications resulting from the vitacoxib administration were noted on subsequent administrations, and all procedures were tolerated well by the horses throughout the study. The elimination half-life (T_1/2λz ) was 4.24 ± 1.98 hr (i.v.), 8.77 ± 0.91 hr (oral paste), and 8.12 ± 4.24 hr (oral tablet), respectively. Maximum plasma concentration (C_max ) was 28.61 ± 9.29 ng/ml (oral paste) and 19.64 ± 9.26 ng/ml (oral tablet), respectively. Area under the concentration-versus-time curve (AUC_last ) was 336 ± 229 ng hr/ml (i.v.), 221 ± 94 ng hr/ml (oral paste), and 203 ± 139 ng hr/ml, respectively. The results showed statistically significant differences between the 2 oral vitacoxib groups in T_max value. T_1/2λz (hr), AUC_last (ng hr/ml), and MRT (hr) were significantly different between i.v. and oral groups. The longer half-life observed following oral administration was consistent with the flip-flop phenomenon.

Development and Investigation of Vitamin C-Enriched Adapalene-Loaded Transfersome Gel: a Collegial Approach for the Treatment of Acne Vulgaris

Adapalene-loaded transfersome gel containing vitamin C as a combination therapy for the management of acne vulgaris was developed in the present study. The transfersome was prepared by reverse-phase evaporation, and the effect of various process parameters were investigated by the Design of Experiment (DOE) approach and optimized based on the particle size (PS), polydispersity index (PDI), zeta potential (ZP), and entrapment efficiency (EE). The selected tranfersomes were further evaluated for their thermal behavior and morphology by transmission electron microscopy and turbidity measurements and incorporated into a gel with/without vitamin C. The gel was evaluated and compared with the marketed product (Adiff gel) for various physicochemical parameters, and in vivo studies in testosterone-induced rat models of acne. The prepared transfersomes had PS in the range of 280 to 400 nm, PDI values of 0.416 to 0.8, ZP of - 38 to - 20 mV, and % EE of 32 to 70%. DSC studies confirmed a positive interaction of the components in the transfersome. Surface morphology confirmed that the vesicles were spherical, unilamellar, and discrete. A relative deformability study showed higher elasticity of the transfersomes compared with Adiff aqs gel. Ascorbyl-6-palmitate in adapalene-loaded transfersome gel containing vitamin C (ADVTG) was found to have a good antioxidant free radical-scavenging activity. An in vitro drug release study showed that the sustained release of the transfersomal formulations was attributed to the flexibility of the vesicles by which penetration was increased. ADVTG was found to be promising in treating acne compared with the marketed product. Graphical Abstract.

Development of MART for the Rapid Production of Nanostructured Lipid Carriers Loaded with All-Trans Retinoic Acid for Dermal Delivery

All-trans retinoic acid (ATRA) has been regarded as a wonder drug for many dermatological complications; however, its application is limited due to the extreme irritation, and toxicity seen once it has sufficiently concentrated into the bloodstream from the skin. Thus, the present study was aimed to increase the entrapment of ATRA and minimize its transdermal permeation. ATRA incorporated within nanostructured lipid carriers (NLCs) were produced by a green and facile thin lipid-film based microwave-assisted rapid technique (MART). The optimization was carried out using the response surface methodology (RSM)-driven artificial neural network (ANN) coupled with genetic algorithm (GA). The liquid lipid and surfactants were seen to play a very crucial role culminating in the particle size (< 70 nm), zeta potential (< - 32 mV), and entrapment of ATRA (> 98%). ANN-GA-optimized NLCs required a minimal quantity of the surfactants, formed within 2 min and were stable for 1 year at different storage conditions. The optimized NLC-loaded creams showed a skin retention (ex vivo) to an extent of 87.42% with no detectable drug in the receptor fluid (24 h) in comparison to the marketed cream which released 47.32% (12 h) of ATRA. The results were in good correlation with the in vivo skin deposition studies. The NLCs were biocompatible and non-skin irritant based on the primary irritation index. In conclusion, the NLCs were seen to have a very high potential in overcoming the drawbacks of ATRA for dermal delivery and could be produced conveniently by the MART.

Pharmacokinetics of vitacoxib in rabbits after intravenous and oral administration

This study describes the pharmacokinetics of vitacoxib in healthy rabbits following administration of 10 mg/kg intravenous (i.v.) and 10 mg/kg oral. Twelve New Zealand white rabbits were randomly allocated to two equally sized treatment groups. Blood samples were collected at predetermined times from 0 to 36 hr after treatment. Plasma drug concentrations were determined using UPLC-MS/MS. Pharmacokinetic analysis was completed using noncompartmental methods via WinNonlin^™ 6.4 software. The mean concentration area under curve (AUC_last ) for vitacoxib was determined to be 11.0 ± 4.37 μg hr/ml for i.v. administration and 2.82 ± 0.98 μg hr/ml for oral administration. The elimination half-life (T_1/2λz ) was 6.30 ± 2.44 and 6.30 ± 1.19 hr for the i.v. and oral route, respectively. The C_max (maximum plasma concentration) and T_max (time to reach the observed maximum (peak) concentration at steady-state) following oral application were 189 ± 83.1 ng/ml and 6.58 ± 3.41 hr, respectively. Mean residence time (MRT_last ) following i.v. injection was 6.91 ± 3.22 and 11.7 ± 2.12 hr after oral administration. The mean bioavailability of oral administration was calculated to be 25.6%. No adverse effects were observed in any rabbit. Further studies characterizing the pharmacodynamics of vitacoxib are required to develop a formulation of vitacoxib for rabbits.

Pharmacokinetics of the novel COX-2 selective inhibitor vitacoxib in cats: The effects of feeding and dose

The purpose of this study was to determine the pharmacokinetics and dose-scaling model of vitacoxib in either fed or fasted cats following either oral or intravenous administration. The concentration of the drug was quantified by UPLC-MS/MS on plasma samples. Relevant parameters were described using noncompartmental analysis (WinNonlin 6.4 software). Vitacoxib is relatively slowly absorbed and eliminated after oral administration (2 mg/kg body weight), with a T_max of approximately 4.7 hr. The feeding state of the cat was a statistically significant covariate for both area under the concentration versus time curve (AUC) and mean absorption time (MAT_fed ). The absolute bioavailability (F) of vitacoxib (2 mg/kg body weight) after oral administration (fed) was 72.5%, which is higher than that in fasted cats (F = 50.6%). Following intravenous administration (2 mg/kg body weight), Vd (ml/kg) was 1,264.34 ± 343.63 ml/kg and Cl (ml kg^-1  hr^-1 ) was 95.22 ± 23.53 ml kg^-1  hr^-1 . Plasma concentrations scaled linearly with dose, with C_max (ng/ml) of 352.30 ± 63.42, 750.26 ± 435.54, and 936.97 ± 231.27 ng/ml after doses of 1, 2, and 4 mg/kg body weight, respectively. No significant undesirable behavioral effects were noted throughout the duration of the study.

Mutagenicity and teratogenicity studies of vitacoxib in rats and mice

Vitacoxib is a new drug candidate for treatment of inflammation, pain and fever as selective cyclooxygenase-2 inhibitors. In the current study, the mice sperm abnormality, mammalian erythrocyte micronucleus and in vivo chromosome aberration, and teratogenicity in SD rats were evaluated. Vitacoxib did not cause an increase in the frequency of structural chromosome aberrations, nor did it produce an increase in the number of micro nucleated polychromatic erythrocytes at dose of 1250–5000 mg/kg body weight (BW). There were no toxicological signs observed in teratogenicity test in female SD rats at dose of 200–5000 mg/kg BW. Based on these results of these studies, vitacoxib does not appear to be observed mutagenicity and teratogenicity.

Evaluation of pharmacokinetic properties of vitacoxib in fasted and fed horses

The pharmacokinetic properties of vitacoxib have not been established completely; current dosage recommendations are based on clinical experiences. The primary objective of this study was to describe plasma concentrations and characterize the pharmacokinetics of vitacoxib formulation following oral administrations in horses. Also, the effect of the state of stomach contents on the absorption of vitacoxib was investigated in fed/fasted horses. Blood samples were collected prior to and at various times up to 72 hr post-administration. Drug concentrations were measured using ultra high-performance liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were calculated using Non-Compartmental Analysis Model 200 in WinNonlin™ software. No complications resulting from the vitacoxib administration were noted. All procedures were tolerated well by the horses throughout the study. C_max was 17.5 ± 9.36 ng/ml (fasted) and 9.47 ± 3.53 ng/ml (fed) following oral administrations. AUC_last was 173.7 ± 137.9 ng hr/ml (fasted) and 113.2 ± 70.8 ng h/ml (fed). No significant differences in pharmacokinetic parameters were noted and the results from the pharmacokinetic analysis were similar between the studies, regardless of precision of dosage and fasted and fed conditions. The study extends previous studies describing the pharmacokinetics of vitacoxib following p.o. administration to the horses. Further studies investigating the pharmacokinetics/pharmacodynamics of vitacoxib are necessary to establish adequate therapeutic protocols (optimal dosage and frequency of administration) in horses.

Safety assessment of vitacoxib: 180-day chronic oral toxicity studies

Vitacoxib, a selective COX-2 inhibitor, is approved for the relief of pain and inflammation associated with orthopedic surgery and osteoarthritis in dogs. In the current study, a chronic toxicity research was performed to evaluate the safety of vitacoxib in male and female rats for long-term. Vitacoxib was dosed orally to groups of rats for 180 days at 1.2, 6, 30 mg/kg bw/day by gavage. The chronic study oral administration of vitacoxib did not show observational or toxicological effects on the body or organ weights, food consumption, hematology and biochemistry at dose 6 mg/kg bw. However, vitacoxib (30 mg/kg) showed minor alterations to histopathology of liver, kidney and stomach related to treatment. These results provide further indication that vitacoxib is safe and well-tolerated in rats after 180 days of daily oral administration at 6 mg/kg bw and the NOAEL for both sexes was 6 mg/kg bw for 180 consecutive days.