Chemoprevention of skin cancer using low HLB surfactant nanoemulsion of 5-fluorouracil: a preliminary study

Abstract

Oral delivery of 5-fluorouracil (5-FU) is difficult due to its serious adverse effects and extremely low bioavailability. Therefore, the aim of present investigation was to develop and evaluate low HLB surfactant nanoemulsion of 5-FU for topical chemoprevention of skin cancer. Low HLB surfactant nanoemulsions were prepared by oil phase titration method. Thermodynamically stable nanoemulsions were characterized in terms of droplet size distribution, zeta potential, viscosity and refractive index. Selected formulations and control were subjected to in vitro skin permeation studies through rat skin using Franz diffusion cells. Optimized formulation F9 was subjected to stability and in vitro cytotoxic studies on melanoma cell lines. Enhancement ratio was found to be 22.33 in formulation F9 compared with control and other formulations. The values of steady state flux and permeability coefficient for formulation F9 were found to be 206.40?±?14.56?µg?cm^?2?h^?1 and 2.064?×?10^?2?±?0.050?×?10^?2?cm?h^?1, respectively. Optimized formulation F9 was found to be physical stable. In vitro cytotoxicity studies on SK-MEL-5 cancer cells indicated that 5-FU in optimized nanoemulsion is much more efficacious than free 5-FU. From these results, it can be concluded that the developed nanoemulsion might be a promising vehicle for chemoprevention of skin cancer.     

Omega 3 fatty acid-enriched nanoemulsion of thiocolchicoside for transdermal delivery: formulation,characterization and absorption studies

Abstract

Thiocolchicoside (TCC) is an effective therapeutic agent against the orthopaedic, traumatic and rheumatologic disorders but it suffer from the drawback of poor bioavailability due to extensive first pass metabolism and low permeability via the oral route. The aim of the present study was to evaluate the potential of nanoemulsion (NE) for bioavailability enhancement of TCC through the transdermal route. The NEs were developed using Linseed: sefsol in 1:1 ratio as the oil phase, span 80, Transcutol P and distilled water as surfactant, co-surfactant and aqueous phase. Furthermore, selected formulations were subjected to physical stability and consequently evaluated for in vitro permeation using porcine skin. The optimized formulation had small average globule diameter of 117?nm with polydispersity index of 0.285. The globules were spherical in shape as observed by transmission electron microscopy. The in vitro skin permeation profile of optimized NE was compared with aqueous solution of TCC. Significant increase in permeability parameters were observed in NEs formulation (p?<?0.05) as compared to aqueous solution of TCC. The steady-state flux (J_ss) and permeability coefficient (K_p) for optimized NE formulation (C1) were found to be 30.63?±?4.18?µg/cm²/h and 15.21?×?10^?3?±?2.81cm²/h, respectively. The results of enhanced permeation through transdermal route suggest that water-in-oil NEs which are compatible with the lipophilic sebum environment of the hair follicle facilitate the transport of TCC, and such transport might be predominantly transfollicular in nature. Overall, these results suggested that water-in-oil NEs are good carriers for transdermal delivery of TCC.     

Optimization and evaluation of pluronic lecithin organogels as a transdermal delivery vehicle for sinomenine

The purpose of the present study was to prepare and optimize sinomenine (SIN) pluronic lecithin organogels system (PLO), and to evaluate the permeability of the optimized PLO in vitro and in vivo. Box–Behnken design was used to optimize the PLO and the optimized formulation was pluronic F127 of 19.61%, lecithin of 3.60% and SIN of 1.27%. The formulation was evaluated its skin permeation and drug deposition both in vitro and in vivo compared with gel. Permeation and deposition studies of PLO were carried out with Franz diffusion cells in vitro and with microdialysis in vivo. In vitro studies, permeation rate (J_ss) of SIN from PLO was 146.55?±?2.93?μg/cm²/h, significantly higher than that of gel (120.39?μg/cm²/h) and the amount of SIN deposited in skin from the PLO was 10.08?±?0.86?μg/cm², significantly larger than that from gel (6.01?±?0.04?μg/cm²). In vivo skin microdialysis studies showed that the maximum concentration (C_max) of SIN from PLO in “permeation study” and “drug-deposition study” were 150.27?±?20.85?μg/ml and 67.95?μg/ml, respectively, both significantly higher than that of SIN from gel (29.66 and 6.73?μg/ml). The results recommend that PLO can be used as an advantageous transdermal delivery vehicle to enhance the permeation and skin deposition of SIN.     

Design, development and evaluation of novel nanoemulsion formulations for transdermal potential of celecoxib

The aim of the present study was to investigate the potential of nanoemulsion formulations for transdermal delivery of celecoxib (CXB). The in vitro skin permeation profile of optimized formulations was compared with CXB gel and nanoemulsion gel. Significant increase in the steady state flux (Jss), permeability coefficient (Kp) and enhancement ratio (Er) was observed in nanoemulsion formulations T1 and T2 (p < 0.05). The highest value of these permeability parameters was obtained in formulation T2, which consisted of 2% (m/m) of CXB, 10% (m/m) of oil phase (Sefsol 218 and Triacetin), 50% (m/m) of surfactant mixture (Tween-80 and Transcutol-P) and 40% (m/m) water. The anti-inflammatory effects of formulation T2 showed a significant increase (p < 0.05) in inhibition after 24 h compared to CXB gel and nanoemulsion gel on carrageenan-induced paw edema in rats. These results suggested that nanoemulsions are potential vehicles for improved transdermal delivery of CXB.     

Preparation and in vivo evaluation of indomethacin loaded true nanoemulsions

Indomethacin, a potent nonsteroidal anti-inflammatory drug, has been used in the treatment of various kinds of pains, inflammation and arthritis. However, oral administration of indomethacin produces serious gastrointestinal adverse effects. Therefore the aim of the present investigation was to evaluate the anti-inflammatory effects, skin irritation, activation energy and histopathology of indomethacin from transdermally applied true nanoemulsion. The anti-inflammatory effects of true nanoemulsions were compared with marketed Indobene^® gel on carrageenan-induced paw edema in rats. Skin irritation tests were performed on Wistar rats for 14 days. The % inhibition value after 12 h application was significant for optimized formulation F6 (83) as compared to marketed Indobene^® gel (P<0.01). Results of skin irritation test indicated that developed true nanoemulsion is safe for human use. The significant decrease in activation energy (1.396 kcal/mol) for indomethacin across rat skin indicated that the stratum corneum lipid bilayers were significantly disrupted (P<0.05). From these results it was concluded that the developed nanoemulsion have great potential for transdermal application of indomethacin.     

Topical delivery of aceclofenac as nanoemulsion comprising excipients having optimum emulsification capabilities: preparation,characterization and in vivo evaluation

Objective: The aim of the present study was to investigate the potential of a nanoemulsion for topical delivery of aceclofenac using different excipients having optimum emulsifying ability rather than their solubilizing capacity.

Methods: The oil-in-water nanoemulsions were prepared by screening the excipients from the nanoemulsion region of pseudoternary phase diagram. The prepared nanoemulsions were subjected to different thermodynamic stability tests. The nanoemulsion formulations that passed thermodynamic stability tests were characterized for viscosity, droplet size, transmission electron microscopy, refractive index and in vitro skin permeation. The in vitro skin permeation profile of optimized nanoemulsion formulation (NE31, containing 23.85% Polyoxy-35-castor oil, 7.95% PEG 400 and 13.6% Triacetin) was compared with that of nanoemulsion gel (NG31) and marketed gel formulation (HIFENAC GEL (HIG)). In vivo anti-inflammatory efficacy studies were also carried out for NE31, NG31 and HIG.

Results: The significant (p < 0.001) increase in in vitro permeability and in vivo anti-inflammatory efficacy of the NG31 formulation was observed as compared with HIG formulation.

Conclusion: It can be concluded that the selection of surfactant and cosurfactant on the basis of their emulsification capabilities other than the solubilizing capacity of drug is an important criterion for the formulation of nanoemulsion.     

Olive oil and clove oil-based nanoemulsion for topical delivery of terbinafine hydrochloride: in vitro and ex vivo evaluation

In this article, formulation studies for terbinafine hydrochloride nanoemulsions, prepared by high-energy ultrasonication technique, are described. Pseudo-ternary phase diagram was constructed in order to find out the optimal ratios of oil and surfactant/co-solvent mixture for nanoemulsion production. Clove and olive oils were selected as oil phase. Based on the droplet size evaluation, maximum nanoemulsion region were determined for formulation development. Further characterization included polydispersity index (PDI), zeta potential, Fourier transform infrared (FT-IR) spectroscopy, morphology, pH, viscosity, refractive index, ex vivo skin permeation, skin irritation, and histopathological examination. Droplet sizes of optimized formulations were in colloidal range. PDI values below 0.35 indicated considerably homogeneous nanoemulsions. Zeta potential values were from 13.2 to 18.1 mV indicating good stability, which was also confirmed by dispersion stability studies. Ex vivo permeation studies revealed almost total skin permeation of terbinafine hydrochloride from the nanoemulsions (96–98%) in 6 hours whereas commercial product reached only 57% permeation at the same time. Maximum drug amounts were seen in epidermis and dermis layers. Skin irritation and histopathological examination demonstrated dermatologically safe formulations. In conclusion, olive oil and clove oil-based nanoemulsion systems have potential to serve as promising carriers for topical terbinafine hydrochloride delivery.     

Formulation,in vitro,and in vivo evaluation of matrix-type transdermal patches containing olanzapine

Transdermal patches of olanzapine were aimed to be prepared to overcome the side effects by oral application. The strategy was formulation of eudragit-based polymeric films to prepare transdermal patches by using nonionic (span-20), anionic (sodium lauryl sulfate), cationic surfactant (benzalkonium chloride), and vegetable oil (olive oil) as permeation enhancers. The patches were subjected to physicochemical, in vitro release and ex vivo permeation studies. On the basis of in vitro release performance, ERL 100:ERS 100 in the ratio of 3:2 was selected for incorporation of permeation enhancers. The permeation studies showed that formulation containing 10% span 20 (OD3) exhibited greatest cumulative amount of drug permeated (19.02?±?0.21?mg) in 72?h, so OD3 was concluded as optimized formulation and assessed for pharmacokinetic, pharmacodynamic, and skin irritation potential. In vivo studies of optimized olanzapine patch in rabbit model revealed prolongation of action with F_rel 116.09% during 72-h study period. Neuroleptic efficacy of transdermal patch was comparable to oral formulation during rotarod and grip test in Wistar albino rats with no skin irritation. Thus, developed formulation of olanzapine is expected to improve the patient compliance, form better dosage regimen, and provide maintenance therapy to psychotic patients.     

Proniosomal transdermal therapeutic system of losartan potassium: development and pharmacokinetic evaluation

The purpose of the current study was to investigate the feasibility of proniosomes as transdermal drug delivery system for losartan potassium. Different preparations of proniosomes were fabricated using different nonionic surfactants, such as Span 20, Span 40, Span 60, Span 80, Tween 20, Tween 40, and Tween 80. Different formulae were prepared and coded as PNG-1 (proniosomal gel-1) to PNG-7. The best in vitro skin permeation profile was obtained with proniosomal formulation PNG-2 in 24?h. The permeability parameters such as flux, permeability coefficient, and enhancement ratio were significant for PNG-2 compared with other formulations (P?<?0.05). This optimized PNG-2 was fabricated in the form of transdermal patch using HPMC gel as a suitable base. Proniosomal transdermal therapeutic system (PNP-H) was found to be the optimized one as it gave better release of drug and better permeation in a steady-state manner over a desired period of time, that is, 24?h through rat skin. In vivo pharmacokinetic study of PNP-H showed a significant increase in bioavailability (1.93 times) compared with oral formulation of losartan potassium. The formulation appeared to be stable when stored at room temperature (30?±?2°C) and at refrigeration temperature (4?±?2°C) for 45 days.     

Ethosomes-based topical delivery system of antihistaminic drug for treatment of skin allergies

Abstract

Cetirizine is indicated for the treatment of allergic conditions such as insect bites and stings, atopic and contact dermatitis, eczema, urticaria. This investigation deals with development of a novel ethosome-based topical formulation of cetirizine dihydrochloride for effective delivery. The optimised formulation consisting of drug, phospholipon 90 G? and ethanol was characterised for drug content, entrapment efficiency, pH, vesicular size, spreadability and rheological behaviour. The ex vivo permeation studies through mice skin showed highest permeation flux (16.300?±?0.300?µg/h/cm²) and skin retention (20.686?±?0.517?µg/cm²) for cetirizine-loaded ethosomal vesicles as compared to conventional formulations. The in vivo pharmacodynamic evaluation of optimised formulation was assessed against oxazolone-induced atopic dermatitis (AD) in mice. The parameters evaluated were reduction in scratching score, erythema score, skin hyperplasia and dermal eosinophil count. Our results suggest that ethosomes are effective carriers for dermal delivery of antihistaminic drug, cetirizine, for the treatment of AD.     

Anti-aging formulation of rosmarinic acid-loaded ethosomes and liposomes

The study was aimed to evaluate the effectiveness of rosmarinic acid (RA) loaded ethosomes (ETHs) and liposomes (LPs) when subjected to the transdermal application. RA-loaded ETHs and LPs were prepared, optimised, and characterised. The ex vivo permeation studies of formulations using mouse abdominal skin were performed. Antioxidant activities and the inhibitory effects of formulations on collagenase and elastase enzymes were measured. Optimised ethosomal formulation (F3) was showed nanometric size range (138?±?1.11?nm) and greatest entrapment (55?±?1.80%), was selected for further transdermal permeation studies. Skin permeation profile of the nanoformulations analysed by HPLC revealed an enhanced permeation of ETHs. Transdermal flux of ETHs was found to be higher than RA solution and LPs. Enzyme inhibitions of ETHs were the significant difference found between ETHs and LPs (p?<?0.05). ETHs were found to be more effective and successful than LPs. Results suggest that ETHs are more effective than LPs for transdermal delivery of RA.     

Evaluation of progesterone permeability from supercritical fluid processed dispersion systems

Abstract

The aim of this study was to investigate the permeability of unique dispersion systems prepared by supercritical fluid (SCF) processing, to deliver bioidentical progesterone (PGN) across mouse skin. Semisolid dispersions of PGN were made up of either polyethylene glycol (PEG) 400/4000, Gelucire 44/14, d-α-tocopheryl PEG 1000 succinate (TPGS), tanscutol P or myritol 318. SCF dispersion systems were compared with various control formulations; a market cream, aqueous suspension, and three conventionally prepared dispersions comelted, cosolvent and physically mixed systems. The permeability coefficient in the absence or presence of a permeation enhancer was evaluated using ex vivo mouse skin. The permeation study results for the TPGS/myritol/transcutol P dispersion system prepared using supercritical carbon dioxide (SC-CO₂) had a two-fold improvement in transdermal permeation over 24?h compared to the control formulation, 245.7 and 126?µg?cm^?2, respectively (p value?<?0.05). In this study, the skin integrity and morphology was also investigated for changes due to the formulation constituents using histological examination and Fourier transform infrared spectroscopy. The particles from the gas-saturated suspension method and SC-CO₂ together with TPGS/myritol/transcutol P may offer potential advantages over the available cream on the market based on the vastly improved lag time and flux of PGN across the skin.     

High-efficient nano-carrier gel systems for testosterone propionate skin delivery

Abstract

The purpose of the current investigation was to evaluate the skin delivery potential of the different nano-carrier gels including liposomal gel, ethosomal gel and microemulsion gel bearing testosterone propionate (TP) as a testosterone deficient therapy. The prepared nano-particles were characterized for their shape, particle size distribution and zeta potential. In vitro skin permeation and in vivo transdermal delivery of nano-carrier gels were studied with the Franz diffusion cells and confocal laser scanning microscopy (CLSM). The results showed that all of nano-particles were almost spherical with low polydispersity and nano-metric size range from 40 to 200?nm. TP ethosomal gel also provided an enhanced transdermal flux of 7.64?±?1.4?μg/cm²/h and a decreased lag time of 0.69?h across rat skin as compared with the other two formulations. The skin penetration efficiency of TP nano-carrier gels also revealed that TP ethosomal gel would enhanced penetration of rhodamine red (RR)-loaded formulation to the deeper layers of the skin (268?µm) than the liposomal gel (192?µm) and microemulsion gel (228?µm). This study demonstrated TP ethosomal gel is a promising nano-carrier for delivering TP through the skin.     

Novel non-ionic surfactant proniosomes for transdermal delivery of lacidipine: optimization using 23 factorial design and in vivo evaluation in rabbits

Abstract

Context: Proniosomes offer a versatile vesicle drug delivery concept with potential for delivery of drugs via transdermal route.

Objectives: To develop proniosomal gel using cremophor RH 40 as non-ionic surfactant containing the antihypertensive drug lacidipine for transdermal delivery so as to avoid its extensive first pass metabolism and to improve its permeation through the skin.

Materials and methods: Proniosomes containing 1% lacidipine were prepared by the coacervation phase separation method, characterized, and optimized using a 2³ full factorial design to define the optimum conditions to produce proniosomes with high entrapment efficiency, minimal vesicle size, and high-percentage release efficiency. The amount of cholesterol (X₁), the amount of soya lecithin (X₂), and the amount of cremophor RH 40 (X₃) were selected as three independent variables.

Results and discussion: The system F4 was found to fulfill the maximum requisite of an optimum system because it had minimum vesicle size, maximum EE, maximum release efficiency, and maximum desirability. The optimized system (F4) was then converted to proniosomal gel using carbopol 940 (1% w/w). In vitro permeation through excised rabbit skin study revealed higher flux (6.48?±?0.45) for lacidipine from the optimized proniosomal gel when compared with the corresponding emulgel (3.04?±?0.13) mg/cm²/h. The optimized formulation was evaluated for its bioavailability compared with commercial product. Statistical analysis revealed significant increase in AUC (0???α) 464.17?±?113.15?ng h/ml compared with 209.02?±?47.35?ng h/ml for commercial tablet. Skin irritancy and histopathological investigation of rat skin revealed its safety.

Conclusions: Cremophor RH 40 proniosomal gel could be considered as very promising nanocarriers for transdermal delivery of lacidipine.     

Texturing formulations for uranium skin decontamination

Abstract

Context: Since no specific treatment exists in case of cutaneous contamination by radionuclides such as uranium, a nanoemulsion comprising calixarene molecules, known for their good chelation properties, was previously designed. However, this fluid topical form may be not suitable for optimal application on the skin or wounds.

Objective: To develop a texturing pharmaceutical form for the treatment of wounded skins contaminated by uranium.

Materials and methods: The formulations consisted in oil-in-water (O/W) nanoemulsions, loaded with calixarene molecules. The external phase of the initial liquid nanoemulsion was modified with a combination of thermosensitive gelifying polymers: Poloxamer and HydroxyPropylMethylcellulose (HPMC) or methylcellulose (MC). These new formulations were characterized then tested by ex vivo experiments on Franz cells to prevent uranyl ions diffusion through excoriated pig ear skin explants.

Results: Despite strong changes in rheological properties, the physico-chemical characteristics of the new nanoemulsions, such as the size and the zeta potential as well as macroscopic aspect were preserved. In addition, on wounded skin, diffusion of uranyl ions, measured by ICP-MS, was limited to less than 5% for both HPMC and MC nanoemulsions.

Conclusions: These results demonstrated that a hybrid formulation of nanoemulsion in hydrogel is efficient to treat uranium skin contamination.     

Nanoemulsion gel-based topical delivery of an antifungal drug: in vitro activity and in vivo evaluation

Abstract

Objective: In this study, attempt has been focused to prepare a nanoemulsion (NE) gel for topical delivery of amphotericin B (AmB) for enhanced as well as sustained skin permeation, in vitro antifungal activity and in vivo toxicity assessment.

Materials and methods: A series of NE were prepared using sefsol-218 oil, Tween 80 and Transcutol-P by slow spontaneous titration method. Carbopol gel (0.5%?w/w) was prepared containing 0.1%?w/w AmB. Furthermore, NE gel (AmB-NE gel) was characterized for size, charge, pH, rheological behavior, drug release profile, skin permeability, hemolytic studies and ex vivo rat skin interaction with rat skin using differential scanning calorimeter. The drug permeability and skin irritation ability were examined with confocal laser scanning microscopy and Draize test, respectively. The in vitro antifungal activity was investigated against three fungal strains using the well agar diffusion method. Histopathological assessment was performed in rats to investigate their toxicological potential.

Results and discussion: The AmB-NE gel (18.09?±?0.6?µg/cm²/h) and NE (15.74?±?0.4?µg/cm²/h) demonstrated the highest skin percutaneous permeation flux rate as compared to drug solution (4.59?±?0.01?µg/cm²/h) suggesting better alternative to painful and nephrotoxic intravenous administration. Hemolytic and histopathological results revealed safe delivery of the drug. Based on combined results, NE and AmB-NE gel could be considered as an efficient, stable and safe carrier for enhanced and sustained topical delivery for AmB in local skin fungal infection.

Conclusion: Topical delivery of AmB is suitable delivery system in NE gel carrier for skin fungal infection.     

Transfersomes: A Novel Vesicular Carrier for Enhanced Transdermal Delivery of Sertraline: Development,Characterization, and Performance Evaluation

The aim of the present study was to investigate transfersomes as a transdermal delivery system for the poorly soluble drug, sertraline, in order to overcome the troubles associated with its oral delivery. Different transfersomal formulations were prepared with non-ionic surfactant (span 80), soya lecithin, and carbopol 940 by the rotary evaporation sonication method. The prepared formulations were characterized for light microscopy, particle size analysis, drug entrapment, turbidity, drug content, rheological studies, in vitro release, ex vivo permeation, and stability studies. The optimized formulation was evaluated for in vivo studies using the modified forced swim model test. FTIR studies showed compatibility of the drug with excipients. The result revealed that sertraline in all of the formulations was successfully entrapped with uniform drug content. Transfersomal gel containing 1.6% of the drug and 20% of span 80 was concluded to be the optimized formulation (EL-SP4), as it showed maximum drug entrapment (90.4±0.15%) and cumulative percent drug release(73.8%). The ex vivo permeation profile of EL-SP4 was compared with the transfersomal suspension, control gel, and drug solution. The transfersomal gel showed a significantly higher (p<0.05) cumulative amount of drug permeation and flux along with lower lag time than the drug solution and drug gel. It also owed to better applicability due to the higher viscosity imparted by the gel rather than the transfersomal suspension, and no skin irritation was observed. The modified forced swim test in mice revealed that the transfersomal gel had better antidepressant activity as compared to the control gel. Thus, the study substantiated that the transfersomal gel can be used as a feasible alternative to the conventional formulations of sertraline with advanced permeation characteristics for transdermal application.     

Formulation of nanoemulsion: a comparison between phase inversion composition method and high-pressure homogenization method

Abstract

There is lot of confusion in the literatures regarding the method of production of nanoemulsion. According to some authors, only the methods using high energy like high-pressure microfluidizer or high-frequency ultra-sonic devices can produce actual nanoemulsions. In contrast to this concept, one research group reported for the first time the preparation of nanoemulsion by a low-energy method. Later on many authors reported about the low-energy emulsification method. The purpose of this work is to formulate, evaluate and compare nanoemulsions prepared using high-energy as well as low-energy method. Nanoemulsions formulated were based on the phase inversion composition technique (low energy method) and were selected from the ternary phase diagram based on the criterion of their being a minimum concentration of S_mix used in the formulation. For high-pressure homogenization method (high energy method) Design-Expert software was used, and the desirability function was probed to acquire an optimized formulation. No significant difference (p?>?0.05) was observed in the globule size of formulations made by each method, but the value of poly-dispersibility index between the two methods was found to be extremely significant (p?<?0.001). A very significant difference (p?<?0.001) was observed in the drug release from formulations made by each method. More than 60% of the drug was released from all the formulations in the initial 2?h of the dissolution study.     

Effect of high-pressure homogenization on formulation of TPGS loaded nanoemulsion of rutin – pharmacodynamic and antioxidant studies

Abstract

Polyphenolic bioflavonoid, Rutin possesses wide range of pharmacological activities. However, it shows poor bioavailability when administered orally. The aim of this study was to formulate and compare the potential of nanoemulsions for the solubility enhancement of rutin (RU) by using different techniques. RU-loaded nanoemulsions were prepared by spontaneous emulsification method and high-pressure homogenization (HPH) technique using sefsol 218 and tocopheryl polyethylene glycol 1000 succinate (TPGS) (1:1), solutol HS15 andtranscutol P as oil phase, surfactant and co-surfactant, respectively. The prepared formulations were compared for various parameters like droplet size, percentage transmittance, zeta potential, viscosity, refractive index and in vitro release. The HPH nanoemulsions showed smaller droplet size and increased in vitro release when compared to nanoemulsions prepared by spontaneous emulsification method. The optimized formulation showed spherical globules with average globule diameter of 18?nm and zeta potential of ?41?mV. Cumulative percentage drug released obtained for RU, PF6 (spontaneous emulsification formulation F6) and HF6 (HPH formulation F6) were 41.5?±?0.04%, 49.5?±?0.06% and 94.8?±?0.03%, respectively, after 6?h. The permeability of RU from HF6 was found to be ≈4.6 times higher than RU suspension during ex vivo everted gut sac studies. Antioxidant activity was determined by using DPPH assay and reducing power assay method. Results showed a high scavenging efficiency toward DPPH radicals by HF6. Anti-inflammatory effect of RU as determined by carrageenan-induced rat paw edema method was found to be higher (75.2?±?4.8%) when compared to RU suspension (46.56?±?3.5%). It can be inferred that TPGS-loaded nanoemulsion of RU serve as an effective tool in increasing solubility and permeability of RU.     

氧化苦参碱凝胶体外经皮渗透及大鼠药动学研究

目的 研究氧化苦参碱凝胶的体外经皮渗透影响因素,并对其在大鼠体内的药动学进行研究。方法 采用Valia-Chien 双室扩散池,以大鼠离体皮肤为渗透屏障,HPLC测定氧化苦参碱浓度,以药物累积渗透量为指标,对药物及渗透促进剂的浓度进行筛选。结果 氧化苦参碱经皮凝胶的最优处方12 h累积渗透量为(18.094±1.253)mg·cm^-2,大鼠静注与经皮给药的血浆药动学研究表明,经皮给药的AUC_(0-t)是注射给药的1.9倍(P<0.01)。结论 氧化苦参碱凝胶的经皮吸收能力良好,能长时间持续释放药物,有望成为新的给药剂型。