Predatory bacterial hydrogels for topical treatment of infected wounds

Wound infection is becoming a considerable healthcare crisis due to the abuse of antibiotics and the substantial production of multidrug-resistant bacteria. Seawater immersion wounds usually become a mortal trouble because of the infection of Vibrio vulnificus. Bdellovibrio bacteriovorus, one kind of natural predatory bacteria, is recognized as a promising biological therapy against intractable bacteria. Here, we prepared a B. bacteriovorus-loaded polyvinyl alcohol/alginate hydrogel for the topical treatment of the seawater immersion wounds infected by V. vulnificus. The B. bacteriovorus-loaded hydrogel (BG) owned highly microporous structures with the mean pore size of 90 μm, improving the rapid release of B. bacteriovorus from BG when contacting the aqueous surroundings. BG showed high biosafety with no L929 cell toxicity or hemolysis. More importantly, BG exhibited excellent in vitro anti-V. vulnificus effect. The highly effective infected wound treatment effect of BG was evaluated on mouse models, revealing significant reduction of local V. vulnificus, accelerated wound contraction, and alleviated inflammation. Besides the high bacterial inhibition of BG, BG remarkably reduced inflammatory response, promoted collagen deposition, neovascularization and re-epithelization, contributing to wound healing. BG is a promising topical biological formulation against infected wounds.

Opportunities and challenges of three-dimensional printing technology in pharmaceutical formulation development

Three-dimensional printing is a technology that prints the products layer-by-layer, in which materials are deposited according to the digital model designed by computer aided design (CAD) software. This technology has competitive advantages regarding product design complexity, product personalization, and on-demand manufacturing. The emergence of 3D technology provides innovative strategies and new ways to develop novel drug delivery systems. This review summarizes the application of 3D printing technologies in the pharmaceutical field, with an emphasis on the advantages of 3D printing technologies for achieving rapid drug delivery, personalized drug delivery, compound drug delivery and customized drug delivery. In addition, this article illustrates the limitations and challenges of 3D printing technologies in the field of pharmaceutical formulation development.

Comparative pharmacokinetics of tetramethylpyrazine phosphate in rat plasma and extracellular fluid of brain after intranasal, intragastric and intravenous administration

The purpose of this study was to compare the pharmacokinetic profiles of tetramethylpyrazine phosphate (TMPP) in plasma and extracellular fluid of the cerebral cortex of rats via three delivery routes: intranasal (i.n.), intragastric (i.g.) and intravenous (i.v.) administration. After i.n., i.g. and i.v. administration of a single-dose at 10 mg/kg, cerebral cortex dialysates and plasma samples drawn from the carotid artery were collected at timed intervals. The concentration of TMPP in the samples was analyzed by HPLC. The area under the concentration-time curve (AUC) and the ratio of the AUCbrain to the AUCplasma (drug targeting efficiency, DTE) was calculated to evaluate the brain targeting efficiency of the drug via these different routes of administration. After i.n. administration, TMPP was rapidly absorbed to reach its peak plasma concentration within 5 min and showed a delayed uptake into cerebral cortex (t max=15 min). The ratio of the AUCbrain dialysates value between i.n. route and i.v. injection was 0.68, which was greater than that obtained after i.g. administration (0.43). The systemic bioavailability obtained with i.n. administration was greater than that obtained by the i.g. route (86.33% vs. 50.39%), whereas the DTE of the nasal route was 78.89%, close to that of oral administration (85.69%). These results indicate that TMPP is rapidly absorbed from the nasal mucosa into the systemic circulation, and then crosses the blood-brain barrier (BBB) to reach the cerebral cortex. Intranasal administration of TMPP could be a promising alternative to intravenous and oral approaches.

Advances in the study of polymeric micelles used in oral administration / 药学学报

Polymeric micelles which are self-assembled from amphiphilic copolymers are thermodynamically stable, and they can solubilize hydrophobic drugs by the hydrophilic core. Many excellent active compounds are confined because of general low oral bioavailability due to poor solubility. Take into account from the two points above, polymeric micelles may be used as proper oral carrier to improve the dissolubility of hydrophobic drugs, and enhance the permeation though gastrointestinal tract, therefore, the pharmacodynamics is elevated. Meanwhile, the segments in copolymers are multivariate, so many kinds of micelles can be obtained, such as, pH- or thermo- sensitive as well as mucoadhesive ones. The modified micelles can alter drug release profiles while solubilizing them, that is why the oral bioavailability increase further. In this review, recent progress of polymeric micelles used in oral administration is summarized, and the prospect of polymeric micelles' application in this field is also evaluated.

Oral ketamine compounds for premedication in children / 中华麻醉学杂志

Objective Intramuscular ketamine is often used for premedication in children. Premeditation can also be administered perorally in children. The aim of this study was to evaluate the efficacy of different compounds of ketamine given perorally as premedication in children. Methods Seventy-five ASA Ⅰ- Ⅱ pediatnc patients weighing 10-30 kg undergoing urologic operation were randomly divided into 5 groups of 15 patients each : (1) control group received atropme 0.015 mg ? kg-1 im 30 min before surgery; (2) DA group received intramuscular diazepam 0.2 mg?kg-1 and atropine 0.015 mg?kg-1 30 min before operation; (3) (4) (5) KMA groups received ketamine 3 mg?kg-1 (K3MA) or5mg?kg-1 (K5MA) or 8mg?kg-1 ( K8 MA) + midazolam 0.5 mg?kg-1 + atropine 0.03 mg?kg per os 30 min before operation. SpO2 and heart rate (HR) were monitored and recorded before premedication and at 0, 5, 10, 15, 20, 30 and 40 min after premedication. Peak effect time, duration of operation and emergence time were also recorded. Sedation, anxiolysis and behaviour at separation from parents, during venepuncture and induction were graded and assessed. Results There was no significant difference in duration of operation among the five groups. The peak effect time in the three KMA groups was shorter than that in control and DA group and was shortest in K8MA group. The three KMA groups were significantly better than control and DA group and the K8 MA group was the best in terms of sedation, anxiolysis and analgesia. The incidence of adverse effects like diploplia headache and agitation was higher in K8MA group. Conclusion K5MA group provides satisfactory sedation and analgesia similer to Kg MA group with less side-effects, so is the oral ketamine compound of choice for premedication in children.