Transcutaneous immunization via rapidly dissolvable microneedles protects against hand-foot-and-mouth disease caused by enterovirus 71.

Recent large outbreaks of hand-foot-and-mouth disease (HFMD) have seriously affected the health of young children. Enterovirus 71 (EV71) is the main causative agent of HFMD. Herein, for the first time, rapidly dissolvable microneedles (MNs) loaded with EV71 virus-like particles (VLPs) were evaluated whether they could induce robust immune responses that confer protection against EV71 infection. The characteristics of prepared MNs including hygroscopy, mechanical strength, insertion capacity, dissolution profile, skin irritation and storage stability were comprehensively assessed. EV71 VLPs remained morphologically stable during fabrication. The MNs made of sodium hyaluronate maintained their insertion ability for at least 3h even at a high relative humidity of 75%. With the aid of spring-operated applicator, EV71 MNs (approximately 500µm length) could be readily penetrated into the mouse skin in vivo, and then rapidly dissolved to release encapsulated antigen within 2min. Additionally, MNs induced slight erythema that disappeared within a few hours. More importantly, mouse immunization and virus challenge studies demonstrated that MNs immunization induced high level of antibody responses conferring full protection against lethal EV71 virus challenge that were comparable to conventional intramuscular injection, but with only 1/10th of the delivered antigen (dose sparing). Consequently, our rapidly dissolving MNs may present as an effective and promising transcutaneous immunization device for HFMD prophylaxis among children.

Development and validation of an UFLC-MS/MS method for enantioselectivity determination of d,l-thero-methylphenidate, d,l-thero-ethylphenidate and d,l-thero-ritalinic acid in rat plasma and its application to pharmacokinetic study.

A chiral UFLC-MS/MS method was established and validated for quantifying d-threo-methylphenidate (d-threo-MPH), l-threo-methylphenidate (l-threo-MPH), d-threo-ethylphenidate (d-threo-EPH), l-threo-ethylphenidate (l-threo-EPH) and d,l-threo-ritalinic acid (d,l-threo-RA) in rat plasma over the linearity range of 1-500ng/mL. Chiral separation was performed on an Astec Chirobiotic V2 column (5µm, 250×2.1mm) with isocratic elution using methanol containing 0.003% ammonium acetate (w/v) and 0.003% trifluoroacetic acid (v/v) at a flow of 0.3mL/min. All analytes and IS were extracted from rat plasma by a one-step liquid-liquid extraction (LLE) method. The intra- and inter-run accuracies were within 85-115%, and the intra- and inter-run precision were <10% for all analytes. Extraction recoveries were 55-62% for d-threo-MPH, 54-60% for l-threo-MPH, 55-60% for d-threo-EPH, 53-57% for l-threo-EPH and 25-30% for d,l-threo-RA. The validated UFLC-MS/MS method successfully applied to the pharmacokinetic interaction study of oral d-threo-MPH and l-threo-MPH (alone or in combination) in female Sprague Dawley rats. The EPH was not detected in rat plasma following oral administrated MPH without EtOH. As far as it is known to the authors, this study is the first one step liquid-liquid extraction method to extract and UFLC-MS/MS method to quantify d-threo-MPH, l-threo-MPH, d-threo-EPH, l-threo-EPH and d,l-threo-RA simultaneously.

Rapidly dissolvable microneedle patches for transdermal delivery of exenatide.

PURPOSE: To assess the feasibility of transdermal delivery of exenatide (EXT) using low-molecular-weight sodium hyaluronate (HA) dissolving microneedles (MNs) patches for type 2 diabetes mellitus therapy. METHODS: Micromold casting method was used to fabricate EXT-loaded dissolving MNs. The characteristics of prepared MNs including mechanical strength, in vitro/in vivo insertion capacity, dissolution profile and storage stability were then investigated. Finally, the in vivo pharmacokinetics and hypoglycemic effects were compared with traditional subcutaneous (SC) injection. RESULTS: EXT-loaded dissolving MNs made of HA possessed sufficient mechanical strength and the strength could be weakened as the water content increases. The EXT preserved its pharmacological activity during fabrication and one-month storage. With the aid of spring-operated applicator, dissolving MNs could be readily penetrated into the skin in vitro/in vivo, and then rapidly dissolved to release encapsulated drug within 2 min. Additionally, transepidermal water loss (TEWL) determinations showed that skin's barrier properties disrupted by MNs recovered within 10-12 h. Transdermal pharmacokinetics and antidiabetic effects studies demonstrated that fabricated EXT MNs induced comparable efficacy to SC injection. CONCLUSIONS: Our rapidly dissolving MNs patch appears to an excellent, painless alternative to conventional SC injection of EXT, and this minimally invasive device might also be suitable for other biotherapeutics.

Preparation and the biopharmaceutical evaluation for the metered dose transdermal spray of dexketoprofen.

The objective of the present work was to develop a metered dose transdermal spray (MDTS) formulation for transdermal delivery of dexketoprofen (DE). DE release from a series of formulations was assessed in vitro. Various qualitative and quantitative parameters like spray pattern, pump seal efficiency test, average weight per metered dose, and dose uniformity were evaluated. The optimized formulation with good skin permeation and an appropriate drug concentration and permeation enhancer (PE) content was developed incorporating 7% (w/w, %) DE, 7% (v/v, %) isopropyl myristate (IPM), and 93% (v/v, %) ethanol. In vivo pharmacokinetic study indicated that the optimized formulation showed a more sustainable plasma-concentration profile compared with the Fenli group. The antiinflammatory effect of DE MDTS was evaluated by experiments involving egg-albumin-induced paw edema in rats and xylene-induced ear swelling in mice. Acetic acid-induced abdominal constriction was used to evaluate the anti-nociceptive actions of DE MDTS. Pharmacodynamic studies indicated that the DE MDTS has good anti-inflammatory and anti-nociceptive activities. Besides, skin irritation studies were performed using rat as an animal model. The results obtained show that the MDTS can be a promising and innovative therapeutic system used in transdermal drug delivery for DE.

Design and evaluation of a monolithic drug-in-adhesive patch for testosterone based on styrene-isoprene-styrene block copolymer.

The purpose of the present study was to design and evaluate a monolithic drug-in-adhesive patch with a novel pressure-sensitive adhesive (PSA) matrix based on styrene-isoprene-styrene (SIS) block copolymer. Testosterone was selected as the model drug. The orthogonal array design for ternary mixtures was employed to optimize the amounts of SIS, C-5 hydrocarbon resin, and liquid paraffin. The drug release percentage, water vapor permeability, adhesive properties were chosen as response variables. The patch formulation was optimized by investigating the effects of the drug loading capacity, the type, and amount of permeation enhancer on the adhesive properties and skin permeation. The compositions of the optimal matrix were: 120 g of SIS copolymer, 120 g of C-5 hydrocarbon resin, 60 g of liquid paraffin. An optimized formulation with maximum skin permeation and acceptable adhesive properties was developed incorporating 2% testosterone and 6% isopropyl myristate. No significant differences for in vitro release, skin permeation, and in vivo absorption were observed between the optimal formulation and Testopatch®. The stability evaluation showed that the patches were stable at 25°C/60% relative humidity for 6 months. The result indicated that SIS copolymer was a suitable and compatible polymer for the development of PSA.

[Characteristics of start-up period in UASB reactor for treating CMC wastewater].

The start-up, the characteristics of granular sludge and the treatment effect of an upflow anaerobic sludge blanket (UASB) reactor under mid-temperature were studied with high concentration carboxymethyl cellulose (CMC) wastewater as treating object. Experiment results showed that it spent 80 days to start up UASB by gradually increasing the influent CMC concentration, and the seed sludge was the mixture of the inoculum granular sludge and the digestion sludge. The removal rate of COD could reach above 80% when the value of influent COD concentration was 4000 mg/L and the organic loading was 6.86 kg/(m3 x d), respectively; granular sludge has been obtained in the reactor, and the specific methanogenic activity of the granular sludge was well.

Preparative isolation of bufalin and cinobufagin from Chinese traditional medicine ChanSu.

In this investigation, a method is developed for the isolation and purification of bufadienolides (resibufogenin, cinobufagin, and bufalin) from the Chinese traditional medicine ChanSu. The crude ChanSu extract is prepared with solvent refluxing under optimal conditions. A new chromatographic approach for separating bufadienolides utilizes silica gel column chromatography with isocratic elution using cyclohexane-acetone (5:1) as the mobile phase to separate resibufogenin, followed by reversed-phase C18 preparative HPLC column using isocratic elution of methanol-water (72:28) to separate bufalin and cinobufagin. Combining these two methods, bufalin and cinobufagin could be completely separated in high purity and recovery, and the amounts obtained were 1.9 and 3.1 g, respectively, from 500 g of ChanSu. These two compounds have been identified by mass spectrometry and 1H NMR, and their purities were quantitated by HPLC at 99% and 98%, respectively.

A novel detection approach based on chromophore-decolorizing with free radical and application to photometric determination of copper with acid chrome dark blue.

A novel detection approach named chromophore-decolorizing with free radicals is developed for determination of trace heavy metal. The hydroxyl radicals (HO) generated from Fe(III) and hydrogen peroxide will oxidize the free chromophore into almost colorless products. The copper-acid chrome dark blue (ACDB) complexation was investigated at pH 5.07. In the presence of Fe(III) and hydrogen peroxide, the excess ACDB was decolorized in the Cu-ACDB reaction solution, and the final solution contained only one color compound, the Cu-ACDB complex. After oxidation of free hydroxyl radicals, the complexation becomes sensitive and selective and it has been used for the quantitation of trace amounts of Cu(II) dissolved in natural water. Beer's law is obeyed in the range from 0 to 0.500 microg mL(-1) Cu(II) and the limit of detection is only 6 microg L(-1) Cu(II). Besides, the Cu-ACDB complex formed was characterized.