Box-Behnken Design for Assessing the Efficiency of Aflatoxin M1 Detoxification in Milk Using Lactobacillus rhamnosus and Saccharomyces cerevisiae.

Milk contaminated with aflatoxin can lead to liver cancer. Aflatoxin B1 (AFB1), a serious animal feed contaminant, is transformed into Aflatoxin M1 (AFM1) and secreted in milk. In this study, a biological method using probiotic bacteria, Lactobacillus rhamnosus (L. rhamnosus) in combination with Saccharomyces cerevisiae (S. cerevisiae), was used to assess their antiaflatoxigenic effect in animal milk. A Box-Behnken design was used to establish the optimal ratio of L. rhamnosus and S. cerevisiae, incubation time, and temperature for efficient AFM1 detoxification from milk. To achieve this, the primary, interaction, and quadratic effects of the chosen factors were investigated. To investigate the quadratic response surfaces, a second-order polynomial model was built using a three-factor, three-level Box-Behnken design. The quantity of AFM1 was detected by the ELISA technique. The results of these experiments obtained an optimum condition in AFM1 detoxification of the three tested factors in order to maximize their effect on AFM1 detoxification in milk. The model was tested in three highly contaminated milk samples to assure the efficacy of the model. AFM1 detoxification was up to 98.4% in contaminated milk samples. These promising results provide a safe, low-cost, and low-time-consuming solution to get rid of the problem of milk contamination with AFM1.

Design and dermatokinetic appraisal of lornoxicam-loaded ultrafine self-nanoemulsion hydrogel for the management of inflammation: In vitro and in vivo studies.

The present study aimed to evaluate the impact of ultrafine nanoemulsions on the transdermal delivery of lornoxicam (LOR) for management of the inflammation. The transdermal administration of LORNE could increase the efficacy of LOR with a reduction in side effects. Merging the beneficial properties of ultrafine nanoemulsions and their components (penetration enhancers) can lead to good solubilization, a small droplet size, and more effective LOR carriers. Therefore, this study aims to develop and evaluate the potential use of ultrafine nanoemulsions of LOR (LORNE) to elucidate their skin targeting for the treatment of inflammation. Based on solubility and pseudo ternary phase diagram tests, ultrafine LORNE composed of Labrafil M 2125 CS, Cremophor RH40, and Transcutol HP to deliver LOR was developed and characterized for its physicochemical properties, emulsification, and in vitro release. The selected LORNE was incorporated into carbopol gel (LORNE-Gel) and examined for ex vivo skin permeation, retention, dermatokinetics, anti-inflammatory efficacy, and skin irritation. The selected LORNE12-Gel could improve skin permeation, retention, and dermatokinetic results significantly (p < 0.05) with enhanced CSkin max and AUC0-48h compared to LOR-Gel. Moreover, LORNE12-Gel showed a remarkable anti-inflammatory effect compared to LOR-Gel after topical application. No signs of skin irritation were observed following treatment, indicating the safety of LORNE12-Gel. Thus, this study demonstrated that LOR-loaded LORNE12-Gel could be promising as an efficient transdermal nanocarrier for an anti-inflammatory alternative.

Design and Optimization of Lornoxicam Dispersible Tablets Using Quality by Design (QbD) Approach.

The present study aims to design and optimize the lornoxicam dispersible tablet (LXDT) formulation using the Quality by design (QbD) approach. A randomized Box-Behnken experimental design was used to characterize the effect of the critical factors, such as filler (MCC/Mannitol) ratio, mixing time, and disintegrant concentration, and assessed for their impacts on the critical quality attributes (responses), including dispersibility time, friability, dissolution efficiency, and content uniformity, respectively. The drug-excipients interaction of the formulation was investigated using FTIR and DSC, respectively. The accelerated stability study at 40 °C/75% relative humidity was performed. FTIR revealed an absence of any significant chemical interaction in solid state. DSC thermogram suggested that LX endothermic peak was slightly decreased due to the dilution effect. LXDT formulations exhibited acceptable friability (0.2 to 0.9%). The dissolution efficiency of LXDT formulations ranged from 72.21 to 93.63%. The overall study showed that the optimum level of independent factors was found to be 3:1 MCC/Mannitol, 11 min mixing time, and 6.23% disintegrant concentration. Accelerated stability studies showed the compendial acceptable hardness, friability, and disintegration times. The application of QbD approach can help in the detailed understanding of the effect of CMAs and CPPs on the CQAs on LXDT final product.

Formulation and in vitro and in vivo evaluation of surfactant-stabilized mucoadhesive nanogels for vaginal delivery of fluconazole.

Surfactant-stabilized mucoadhesive nanogels (NGs) for vaginal delivery of fluconazole (FLZ) were studied and evaluated in this work. FLZ-NG formulations were prepared using two different types of mucoadhesive polymers, Carbopol 934 (Ca934) and Pluronic F-127 (PF127). A rheology study revealed a non-Newtonian pseudoplastic flow behavior (shear thinning) in the prepared NGs. The viscosity of Ca934 NG (0.47 Pa s) was much lower compared to the PF127 NG (6.10 Pa s). The rheology study results correlated well with the in vitro FLZ release profile from the NG formulations. A pH study (pH = 3.90-4.90) revealed that the formulations were physiologically suitable for vaginal application, to avoid the irritation of the vaginal mucosa. Finally, in vitro and in vivo antimicrobial tests were performed. FLZ incorporated into the Ca934 gel had the strongest antimicrobial effect, with a mean inhibition zone of 24 ± 1.6 mm. Based on these results, it was concluded that the mucoadhesive NG incorporating FLZ resulted in a sustained release and enhanced antimicrobial effect, which would enhance and prolong the therapeutic effects of vaginally delivered FLZ.

The Development of Self-nanoemulsifying Liquisolid Tablets to Improve the Dissolution of Simvastatin.

The aim of this work was to develop self-nanoemulsifying liquisolid tablets (SNELT) to enhance the dissolution profile of poorly water-soluble simvastatin. SNELT present a unique technique of incorporating self-nanoemulsifying drug delivery systems (SNEDDS) into tablets. Optimized SNEDDS containing different oils, Cremophor® RH 40 (surfactant) and Transcutol® HP (co-surfactant), at different ratios, were used as liquid vehicles and loaded on carrier material, microcrystalline cellulose (MCC), and coating material, Cab-o-sil® H-5 (nanosize colloidal silicon dioxide) powders at different loading factors (L f ) and fixed excipient ratio (R = 20). The effect of using different carrier materials, granulated mannitol, crystalline mannitol, and maltodextrin with MCC at different ratios, and different coating materials, Aeroperl® 300 (granulated silicon dioxide) at different excipient ratios (R), was also emphasized. Liquisolid powders with acceptable flowability, compressibility, and tablet weight were compressed into tablets. Results revealed that powders with L f = 0.2 possessed the most preferable properties to be tableted. SNELT with MCC and Cab-o-sil® H-5 were able to generate nanoemulsions and to enhance the cumulative percent of drug dissolved at 60 min significantly to reach up to 90%. Furthermore, using carrier material (granulated mannitol/MCC at ratio 3:1) enabled SNELT to disperse into nanoemulsion (Z-average = 25.7 nm) and improved the dissolution profile significantly to reach 99% at 60 min. Cab-o-sil® H-5 proved to be a better coating material compared to Aeroperl® 300. In conclusion, developed SNELT were promising in enhancing in vitro dissolution of simvastatin and excipients highly affect SNELT's performance.

Effect of Trigonella foenum-graecum L. on Metabolic Activity of CYP2D6 and CYP3A4.

BACKGROUND: The present study investigated the effect of fenugreek seeds powder and its alcoholic extract on metabolic activity of drug-metabolizing enzymes CYP2D6 and CYP3A4. MATERIALS AND METHODS: Dextromethorphan (DEX) was used as a probe for measuring metabolic activity, based on its CYP2D6- and CYP3A4-mediated metabolism to dextrorphan (DOR) and 3-methoxymorphinan (3-MM), respectively. For the in vitro investigations, DEX (25µM) was incubated with human liver microsomes and NADPH and tested with and without the fenugreek extract. For the in vivo study, phase I, 6 subjects received a single dose of DEX (30 mg); in phase II, after washout period, the fenugreek seeds powder was administered for 1 week and DEX was administered with its last dose. RESULTS: In vitro, fenugreek extract inhibits CYP2D6-mediated O-demethylation of DEX. Higher concentrations (50 and 100µg/ml) of extract inhibit CYP2D6 and CYP3A4 activity. In vivo results indicated that fenugreek does not significantly inhibit CYP2D6 and CYP3A4 metabolic activity. There was no significant change in the levels of DEX metabolites (DOR 12% and 3-MM 9%) excreted in urine and their urine metabolic ratios (P values: 0.257 and 0.333 DEX/DOR and DEX/3-MM, respectively). CONCLUSION: In vitro and in vivo observations suggested that fenugreek may not have substantial effect on the metabolic activity of CYP2D6 and CYP3A4.

Effects of fenugreek, garden cress, and black seed on theophylline pharmacokinetics in beagle dogs.

CONTEXT: Herb-drug interactions are a serious problem especially for drugs with a narrow therapeutic index, taking into consideration that herbal medicines are commonly used in various parts of the world. OBJECTIVE: The present study investigates the effect of fenugreek, garden cress, and black seed on the pharmacokinetics of theophylline in beagle dogs. MATERIALS AND METHODS: Beagle dogs received theophylline (200 mg) orally and blood samples were withdrawn at different time intervals (0.33, 0.66, 1.0, 1.5, 2, 3, 4, 6, 8, 12, 24, and 30 h). After a suitable washout period, each herb was given orally at doses of 25, 7.5, and 2.5 g, twice daily for 7 d. On the eighth day, theophylline was re-administrated orally and blood samples were collected. Plasma concentrations of theophylline were determined using HPLC and pharmacokinetic parameters were calculated using a non-compartmental analysis. RESULTS: Treatment with fenugreek (25 g, orally) lead to a decrease in Cmax and AUC0-t of theophylline of about 28% (p < 0.05) and 22% (p < 0.05), respectively, with no significant changes in T1/2λ compared with the baseline values. Garden cress caused a decrease in Cmax to a lesser extent and delayed Tmax of theophylline (2.10 ± 0.24 h versus 3.40 ± 0.74 h), while AUC0-∞ increased by 37.44%. No significant effect was observed for the black seed treatment on theophylline disposition as measured by Cmax, Tmax, AUC0-∞, and CL/F. DISCUSSION AND CONCLUSION: The concurrent use of fenugreek or garden cress alters theophylline pharmacokinetic behavior in an animal model. This could represent a modulation in cytochrome P450 activity, which is responsible for theophylline metabolism in beagle dogs. Further confirmation of these results in humans will warrant changes in theophylline dosing before the co-administration of such herbs.

Effect of Curcuma longa on CYP2D6- and CYP3A4-mediated metabolism of dextromethorphan in human liver microsomes and healthy human subjects.

Effect of Curcuma longa rhizome powder and its ethanolic extract on CYP2D6 and CYP3A4 metabolic activity was investigated in vitro using human liver microsomes and clinically in healthy human subjects. Dextromethorphan (DEX) was used as common probe for CYP2D6 and CYP3A4 enzymes. Metabolic activity of CYP2D6 and CYP3A4 was evaluated through in vitro study; where microsomes were incubated with NADPH in presence and absence of Curcuma extract. In clinical study phase-I, six healthy human subjects received a single dose (30 mg) of DEX syrup, and in phase-II DEX syrup was administered with Curcuma powder. The enzyme CYP2D6 and CYP3A4 mediated O- and N-demethylation of dextromethorphan into dextrorphan (DOR) and 3-methoxymorphinan (3-MM), respectively. Curcuma extract significantly inhibited the formation of DOR and 3-MM, in a dose-dependent and linear fashion. The 100 µg/ml dose of curcuma extract produced highest inhibition, which was about 70 % for DOR and 80 % for 3-MM. Curcuma significantly increases the urine metabolic ratio of DEX/DOR but the change in DEX/3-MM ratio was statistically insignificant. Present findings suggested that curcuma significantly inhibits the activity of CYP2D6 in in vitro as well as in vivo; which indicates that curcuma has potential to interact with CYP2D6 substrates.

Effects of Nigella sativa, Lepidium sativum and Trigonella foenum-graecum on sildenafil disposition in beagle dogs.

The present study was conducted to investigate the effects of some commonly used herbs namely Nigella sativa, Lepidium sativum and Trigonella foenum-graecum on the pharmacokinetics of sildenafil in beagle dogs. The study design involved four treatments in a non-balanced crossover design. Sildenafil was given one tablet 100 mg orally to each dog and blood samples were obtained. After a suitable washout period, animals were commenced on a specific herb treatment for 1 week. Blood samples were withdrawn at different time intervals and sildenafil was analyzed by HPLC method. Oral administration of Nigella sativa resulted in reduction of AUC0-∞, C max and t 1/2 as compared to the control. Treatment of Lepidium sativum resulted in a significant reduction in the C max and AUC. There were no significant differences between the rests of the pharmacokinetic parameters relative to those of the control. For Trigonella foenum-graecum, the effects were similar to those obtained in case of Lepidium sativum. It was concluded that concurrent use of investigated herbs alters the pharmacokinetics of sildenafil. Co-administration of investigated herbs should be cautious since their concomitant use might result in decrease in sildenafil bioavailability.

Evaluation of skin permeation and analgesic activity effects of carbopol lornoxicam topical gels containing penetration enhancer.

The current study was designed to develop a topical gel formulation for improved skin penetration of lornoxicam (LOR) for enhancement of its analgesic activity. Moreover, the effect of different penetration enhancers on LOR was studied. The LOR gel formulations were prepared by using hydroxylpropyl methylcellulose (HPMC) and carbopol. The carbopol gels in presence of propylene glycol (PG) and ethanol were developed. The formulated gels were characterized for pH, viscosity, and LOR release using Franz diffusion cells. Also, in vitro skin permeation of LOR was conducted. The effect of hydroxypropyl ß-cyclodextrin (HP ß-CD), beta-cyclodextrin (ß-CD), Tween 80, and oleic acid on LOR permeation was evaluated. The optimized LOR gel formulation (LORF8) showed the highest flux (14.31 µg/cm(2)/h) with ER of 18.34 when compared to LORF3. Incorporation of PG and HP ß-CD in gel formulation (LORF8) enhanced the permeation of LOR significantly. It was observed that LORF3 and LORF8 show similar analgesic activity compared to marketed LOR injection (Xefo). This work shows that LOR can be formulated into carbopol gel in presence of PG and HP ß-CD and may be promising in enhancing permeation.

Effect of Garden Cress Seeds Powder and Its Alcoholic Extract on the Metabolic Activity of CYP2D6 and CYP3A4.

The powder and alcoholic extract of dried seeds of garden cress were investigated for their effect on metabolic activity of CYP2D6 and CYP3A4 enzymes. In vitro and clinical studies were conducted on human liver microsomes and healthy human subjects, respectively. Dextromethorphan was used as a common marker for measuring metabolic activity of CYP2D6 and CYP3A4 enzymes. In in vitro studies, microsomes were incubated with NADPH in presence and absence of different concentrations of seeds extract. Clinical investigations were performed in two phases. In phase I, six healthy female volunteers were administered a single dose of dextromethorphan and in phase II volunteers were treated with seeds powder for seven days and dextromethorphan was administered with last dose. The O-demethylated and N-demethylated metabolites of dextromethorphan were measured as dextrorphan (DOR) and 3-methoxymorphinan (3-MM), respectively. Observations suggested that garden cress inhibits the formation of DOR and 3-MM metabolites. This inhibition of metabolite level was attributed to the inhibition of CYP2D6 and CYP3A4 activity. Garden cress decreases the level of DOR and 3-MM in urine and significantly increases the urinary metabolic ratio of DEX/DOR and DEX/3-MM. The findings suggested that garden cress seeds powder and ethanolic extract have the potential to interact with CYP2D6 and CYP3A4 substrates.

Pharmacokinetic interaction studies of fenugreek with CYP3A substrates cyclosporine and carbamazepine.

The present study investigated the effect of fenugreek seed powder on disposition of CYP3A substrates, cyclosporine and carbamazepine. Rabbits were treated with fenugreek seed powder (300 mg/kg p.o.) for 8 days and on 8th day the single dose of cyclosporine (30 mg/kg, p.o.) and carbamazepine (40 mg/kg, p.o.) were administered to the corresponding group after 1 h of fenugreek administration. Blood samples were drawn at several time points and analyzed by using UPLC-MS (cyclosporine) and HPLC (carbamazepine). Pharmacokinetic parameters were calculated by using PK Solver. The present investigation reveals that there was no statistically significant difference between pre- and post-treated pharmacokinetic parameters such as AUC(o-t), AUC(o-∞), C(max), T(max), T(1/2), K(el), MRT(o-∞) , V(z/F), and Cl/F for cyclosporine and carbamazepine. Two tailed "P" values for all these pharmacokinetic parameters were more than 0.05, indicating insignificant impact of fenugreek treatment on the disposition of cyclosporine and carbamazepine. Further, fenugreek may also not have any significant effect on the functionality of P-glycoprotein as cyclosporine is a substrate to P-glycoprotein. The outcomes of present study suggested that fenugreek may not likely to interfere cyclosporine and carbamazepine pharmacokinetics, when co-administered with these drugs.

Modulation of CYP2D6 and CYP3A4 metabolic activities by Ferula asafetida resin.

Present study investigated the potential effects of Ferula asafetida resin on metabolic activities of human drug metabolizing enzymes: CYP2D6 and CYP3A4. Dextromethorphan (DEX) was used as a marker to assess metabolic activities of these enzymes, based on its CYP2D6 and CYP3A4 mediated metabolism to dextrorphan (DOR) and 3-methoxymorphinan (3-MM), respectively. In vitro study was conducted by incubating DEX with human liver microsomes and NADPH in the presence or absence of Asafetida alcoholic extract. For clinical study, healthy human volunteers received a single dose of DEX alone (phase-I) and repeated the same dose after a washout period and four-day Asafetida treatment (phase-II). Asafetida showed a concentration dependent inhibition on DOR formation (in vitro) and a 33% increase in DEX/DOR urinary metabolic ratio in clinical study. For CYP3A4, formation of 3-MM in microsomes was increased at low Asafetida concentrations (10, 25 and 50 µg/ml) but slightly inhibited at the concentration of 100 µg/ml. On the other hand, in vivo observations revealed that Asafetida significantly increased DEX/3-MM urinary metabolic ratio. The findings of this study suggest that Asafetida may have a significant effect on CYP3A4 metabolic activity. Therefore, using Ferula asafetida with CYP3A4 drug substrates should be cautioned especially those with narrow therapeutic index such as cyclosporine, tacrolimus and carbamazepine.

Lepidium sativum but not Nigella sativa affects carbamazepine disposition in an animal model.

Efficacy and safety profile of a drug may be affected when concomitantly used with herbal medicines. The present study was conducted to investigate the effects of some commonly used herbal products viz. Nigella sativa (Black seed) and Lepidium sativum (Garden cress) on the pharmacokinetics of carbamazepine (CBZ), a narrow therapeutic index drug, in an animal model. In a control group, five rabbits received 40 mg/kg of CBZ orally and blood samples were withdrawn at different time intervals (0, 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 and 24 hrs) from a marginal ear vein. After a suitable washout period, an aqueous saline suspension of Nigella sativa (200 mg/kg) or Lepidium sativum (150 mg/kg) was given orally for eight days to the rabbits. On day eight, CBZ (40 mg/kg) was re-administrated orally and blood samples were collected using the same sampling scheme. Drug levels in plasma were determined by liquid chromatography and pharmacokinetic parameters were calculated using non-compartmental analysis. No significant difference was observed in the maximum concentration (Cmax), area under concentration curve (AUC), half-life (T1/2), clearance (Cl/F) and volume of distribution (Vz/F) of CBZ following Nigella sativa treatment. Whereas, increased Cmax, absorption rate measured by the time to Cmax (Tmax), and prolongation of the terminal elimination half-life (T1/2) were observed after the co-administration with Lepidium sativum. Findings of the present study suggest that concurrent use of Lepidium sativum alters the pharmacokinetics of CBZ in an animal model. Further confirmation of these results in humans will warrant changes in CBZ dose and/or frequency before co-administration with these herbal medicines.

Effects of Lepidium sativum, Nigella sativa and Trigonella foenum-graceum on phenytoin pharmacokinetics in beagle dogs.

The present work was designed to evaluate the effect of some commonly used herbs viz. garden cress (Lepidium sativum), black seed (Nigella sativa) and fenugreek (Trigonella foenum-graceum) on the disposition of phenytoin after oral administration in a dog model. Phenytoin was given orally at a dose of 50 mg, and blood samples were obtained for the determination of drug's pharmacokinetic parameters. After a suitable washout period, animals were commenced on a specific herb treatment for one week. Garden cress treatment caused a modest increase in maximum observed concentration (Cmax ) and terminal half-life (T1/2λ ) of phenytoin with a reduction in clearance by 33%. The effect of black seed therapy was more drastic on drug elimination and to a lesser extent on its volume of distribution at steady state (Vss ) with a consequent reduction in systemic exposure measured by area under the curve (AUC0-∞ ) by about 87%. The effect of fenugreek therapy resembled, albeit to a lesser extent, that of black seed with a significant reduction in AUC0-∞ by ~72%. In addition, there was a 73% increase in Vss . Our findings suggest that the phenytoin disposition can be significantly altered by the concurrent consumption of tested herbal products.

Percutaneous absorption and antibacterial activities of lipid nanocarriers loaded with dual drugs for acne treatment.

The aim of this study was to develop lipid nanocarriers that combine tretinoin and tetracycline for the efficient topical delivery to treat acne vulgaris. Two different nanocarriers, nanoemulsions (NEs) and nanostructured lipid carriers (NLCs), were prepared, and we examined their average size, zeta potential, drug encapsulation percentage, and drug permeation via the skin. The antibacterial activities of the nanosystems against Staphylococcus aureus, Pseudomonas aeruginosa, and Propionibacterium acnes were evaluated by an agar diffusion assay and the amount of total protein. A ca. 200-nm particle size was achieved with the prepared nanoparticles. The size increased when incorporating a cationic surfactant. Dual-drug loading did not largely affect the size of negatively charged nanoparticles, but significantly reduced the particle size of positively charged nanocarriers. NEs and NLCs exhibited high entrapment of tretinoin which ranged 60-100%. Tetracycline mainly resided in the aqueous phase, with ca. 10% of molecules located at the particulate interface. An in vitro skin permeation study showed that NLCs enhanced tetracycline flux by about 2-times over the control solution. Tretinoin permeation was generally unaffected after nanoparticulate encapsulation. There was no significant difference in tretinoin delivery before or after tetracycline incorporation, while tetracycline permeation significantly decreased by 2-fold in the dual-drug system. Nanoparticulate loading mostly maintained the antibacterial activity of tetracycline. Negatively charged NEs and NLCs even strengthened the antibacterial ability against S. aureus compared to the control solution. This is the first report examining skin permeation and antibacterial activities of dual-drug nanocarriers for acne treatment.

Formulation design and evaluation of quantum dot-loaded nanostructured lipid carriers for integrating bioimaging and anticancer therapy.

AIM: The authors studied the bioimaging and delivery of drug-entrapped, nanostructured lipid carriers with quantum dots (QDs), called QDNLCs, for integrating imaging and therapy. MATERIALS & METHODS: Nanostructured lipid carriers consisting of QDs, including lipophilic QDs, carboxyl-function QDs or PEG QDs were prepared. Application of the nanocarriers was evaluated by cytotoxicity, cell migration, cellular uptake, in vivo real-time tumor monitoring and drug accumulation in tumors. RESULTS: All QDNLCs exhibited a size of 245 nm with camptothecin encapsulation of >99%. Cytotoxicity of the nanoparticles against melanoma cells was superior to that of free camptothecin. Carboxylic acid-conjugated QDNLCs (C-QDNLCs) showed the highest cell internalization and in vivo fluorescence labeling compared with the other carriers. Real-time bioimaging demonstrated that C-QDNLCs maintained signaling in tumors for at least 24 h. The camptothecin accumulation in melanomas increased by 6.4-fold after incorporation into C-QDNLCs. CONCLUSION: For the first time, nanostructured lipid carriers were coordinated with QDs and an anticancer drug to provide efficient tumor imaging and drug delivery. Original submitted 1 May 2012; Revised submitted 30 August 2012; Published online 5 February 2013.

Maximizing dermal targeting and minimizing transdermal penetration by magnolol/honokiol methoxylation.

Magnolol and honokiol, predominant active compounds in the family Magnoliaceae, are known to exhibit strong anti-inflammatory activities against dermal disorders. We attempted to modify the structures of magnolol and honokiol by methoxylation to optimize the skin delivery ability. Absorption of these permeants into and through the skin was performed at both an infinite dose and saturated solubility. Superoxide anion and elastase released from human neutrophils were the biomarkers used to examine anti-inflammatory potencies of these permeants. The safety of the permeants was evaluated by keratinocyte viability and in vivo bioengineering techniques. Topical magnolol and honokiol at an infinite dose (7.5 mM) showed skin accumulations of 0.22 and 0.16 nmol/mg, respectively. Methoxylation significantly enhanced their skin absorption. Deposition amounts of dimethylmagnolol and dimethylhonokiol were respectively 15- and 7-fold greater than those of magnolol and honokiol. Contrary to the skin accumulation results, the transdermal penetration across skin decreased following methoxylation. No transdermal delivery occurred for dimethylhonokiol. Skin uptake of 4'-O-methylhonokiol was 2-fold higher than that of 2-O-methylhonokiol, although they are isomers. Methoxylated permeants demonstrated selective absorption into follicles, which showed 3-5-fold higher follicular amounts compared to magnolol and honokiol. The relative order of anti-inflammatory activities was honokiol>2-O-methylmagnolol>dimethylhonokiol>magnolol. The other compounds exhibited negligible or negative responses in activated neutrophils. Magnolol and honokiol induced slight but significant keratinocyte cytotoxicity and stratum corneum disruption. Daily administration of methoxylated permeants, especially dimethylhonokiol, produced no skin irritation for up to 7 days. Methoxylated magnolol and honokiol can be efficient and safe candidates for treating inflammatory skin disorders.

Risk assessment of excess drug and sunscreen absorption via skin with ablative fractional laser resurfacing : optimization of the applied dose for postoperative care.

The ablative fractional laser is a new modality used for surgical resurfacing. It is expected that laser treatment can generally deliver drugs into and across the skin, which is toxicologically relevant. The aim of this study was to establish skin absorption characteristics of antibiotics, sunscreens, and macromolecules via laser-treated skin and during postoperative periods. Nude mice were employed as the animal model. The skin received a single irradiation of a fractional CO2 laser, using fluences of 4-10 mJ with spot densities of 100-400 spots/cm(2). In vitro skin permeation using Franz cells was performed. Levels of skin water loss and erythema were evaluated, and histological examinations with staining by hematoxylin and eosin, cyclooxygenase-2, and claudin-1 were carried out. Significant signs of erythema, edema, and scaling of the skin treated with the fractional laser were evident. Inflammatory infiltration and a reduction in tight junctions were also observed. Laser treatment at 6 mJ increased tetracycline and tretinoin fluxes by 70- and 9-fold, respectively. A higher fluence resulted in a greater tetracycline flux, but lower skin deposition. On the other hand, tretinoin skin deposition increased following an increase in the laser fluence. The fractional laser exhibited a negligible effect on modulating oxybenzone absorption. Dextrans with molecular weights of 4 and 10 kDa showed increased fluxes from 0.05 to 11.05 and 38.54 µg/cm(2)/h, respectively. The optimized drug dose for skin treated with the fractional laser was 1/70-1/60 of the regular dose. The skin histology and drug absorption had recovered to a normal status within 2-3 days. Our findings provide the first report on risk assessment of excessive skin absorption after fractional laser resurfacing.

Camptothecin-Loaded Liposomes with α-Melanocyte-Stimulating Hormone Enhance Cytotoxicity Toward and Cellular Uptake by Melanomas: An Application of Nanomedicine on Natural Product.

In this study, we attempted to develop functional liposomes loaded with camptothecin and attached to α-melanocyte-stimulating hormone (α-MSH) to target melanoma cells. The liposomes were mainly composed of phosphatidylcholine, cholesterol, and stearylamine, and were characterized by the vesicle size, zeta potential, camptothecin encapsulation efficiency, and release behavior. Results revealed that α-MSH liposomes possessed an average size of approximately 250 nm with a surface charge of 60 mV. Camptothecin was successfully entrapped by the targeted liposomes with an encapsulation percentage of nearly 95%. The liposomes provided sustained and controlled camptothecin release. Non-targeted liposomes with the drug exerted superior cytotoxicity against melanomas compared to the free control. Cell viability was reduced from 48% to 32% compared to conventional liposomes. Peptide ligand conjugation further promoted cytotoxicity to 18% viability, which was a 2.7-fold decrease versus the free control. According to the images of fluorescence microscopy, α-MSH liposomes exhibited greater cell endocytosis than did non-targeted liposomes and the free control. α-MSH liposomes were predominantly internalized in the cytoplasm. These findings demonstrate that α-MSH liposomes could enhance the anti-melanoma activity of camptothecin owing to their targeting ability and controlled drug delivery.