Development of a novel vesicular system using a binary mixture of sorbitan monostearate and polyethylene glycol fatty acid esters for rectal delivery of rutin.

Anorectal diseases, such as hemorrhoids, are bothersome benign conditions that warrant special attention. The design of an optimized vesicular system for localized rectal delivery can be a suitable conservative treatment. The feasibility of preparing proniosomes using different types of Gelucires®, in combination with Span(®) 60 as binary mixtures of nonionic surfactants, was checked, then the prepared proniosomes using Span 60 or Span 60/Gelucire were compared to conventional niosomes through investigations comprising the following: encapsulation efficiency (EE%); particle-size analysis; transmission electron microscopy; zeta potential (Z), and in vitro release study and ex vivo permeation study using excised rat rectum. All preparations showed satisfactory stability (Z >30 mV), particle size <300 nm with niosomes showing the lowest EE%, and the largest particle size, together with the least amount of drug released or accumulated in the rectal walls. Span 60/Gelucire proniosomes exhibited lower particle size as well as better release and permeation results, compared to Span 60 proniosomes. Span 60/Gelucire 44/14 (2:1) proniosomes attained the highest percentage of drug released (98.39%) and drug deposition in the rectal walls (86.26%) after 8 hours, which therefore seems to be the most suitable formula able to achieve targeted therapeutic efficacy, aiming to improve the patient's quality of life.

Miniaturized ionophore-based potentiometric sensors for the flow-injection determination of metformin in pharmaceutical formulations and biological fluids.

Miniaturized potentiometric sensors based on ß-cyclodextrins (ß-CDs) are described for determination of metformin (Mf) in pharmaceutical preparations and biological fluids. Electrode matrix compositions are optimized on the basis of the nature and content of sensing ionophore, ionic sites and plasticizers. Coated wire electrodes (CWEs) modified with heptakis(2,3,6-tri-O-methyl)-ß-CD, sodium tetrakis(4-fluorophenyl)borate (NaTFPB) and 2-fluorophenyl 2-nitrophenyl ether (f-NPE), work satisfactorily in the concentration range from 10(-6) to 10(-1) mol L(-1) with Nernstian compliance (55.7 ± 0.4 mV per decade activity) and a detection limit of 8 × 10(-7) mol L(-1). Incorporation of ß-CD as a molecular recognition element improved the electrode sensitivity and selectivity due to encapsulation of Mf into the ß-CD cavity (host-guest interaction). The developed electrodes have been successfully applied for the potentiometric determination of Mf under batch and flow injection analysis (FIA). FIA allows analysis of 90 samples per h offering the advantages of simplicity, accuracy and automation feasibility. The dissolution profile for metformin pharmaceutical samples (Cidophage®) was monitored using the proposed electrode in comparison with the official spectrophotometric methods. Characterization of the formed Mf-ß-CD inclusion complexes is discussed in detail.

Crosslink among phosphatidylinositol-3 kinase/Akt, PTEN and STAT-5A signaling pathways post liposomal galactomannan hepatocellular carcinoma therapy.

Liposomal drug-delivery systems (LDDs) provide a promising opportunity to precisely target organs, improve drug bioavailability and reduce systemic toxicity. On the other hand, PI3K/Akt signaling pathways control various intracellular functions including apoptosis, invasion and cell growth. Hyper activation of PI3K and Akt is detected in some types of cancer that posses defect in PTEN. Tracking the crosstalk between PI3K/Akt, PTEN and STAT 5A signaling pathways, in cancer could result in identifying new therapeutic agents. The current study, identified an over view on PI3K/Akt, PTEN and STAT-5A networks, in addition to their biological roles in hepatocellular carcinoma (HCC). In the current study galactomannan was extracted from Caesalpinia gilliesii seeds then loaded in liposomes. Liposomes were prepared employing phosphatidyl choline and different concentrations of cholesterol. HCC was then induced in Wistar albino rats followed by liposomal galactomannan (700 ± 100 nm) treatment. Liver enzymes as well as antioxidants were assessed and PI3K/Akt, PTEN and STAT-5A gene expression were investigated. The prepared vesicles revealed entrapment efficiencies ranging from 23.55 to 69.17%, and negative zeta potential values. The optimum formulation revealed spherical morphology as well as diffusion controlled in vitro release pattern. Liposomal galactomannan elucidated a significant reduction in liver enzymes and MDA as well as PI3K/Akt, PTEN and STAT 5A gene expression. A significant elevation in GST and GSH were deduced. In conclusion, Liposomal galactomannan revealed a promising candidate for HCC therapy.

Remineralization potential of grape seed extract hydrogels on bleached enamel compared to fluoride gel: An in vitro study.

BACKGROUND: Remineralizing of bleached enamel is a common procedure that aims to compensate enamel mineral lose. This study aimed to evaluate the remineralization effectiveness of experimentally prepared grape seed extract hydrogels (GSE) compared to fluoride gel on bleached enamel. MATERIAL AND METHODS: Thirty extracted maxillary incisor were bleached using white smile bleaching agent. Bleached specimens were divided into three groups (10/group) according to the remineralizing agents tested: [GSE 6%, GSE 10%, or fluoride gel]. After bleaching and remineralization procedure, the specimens were stored in artificial saliva at 37°C. Micro-hardness and Energy-Dispersive X-ray and ultra-morphological evaluation were tested at baseline, after bleaching and after remineralization. RESULTS: Statistical significant decrease on mean micro-hardness values had resulted after bleaching procedure compared to baseline, followed by a significant increase in GSE (10%) and fluoride groups. GSE (6%) application showed the least statistical significant mean micro-hardness, which was statistically insignificant different compared to bleaching procedure. Elemental analysis results revealed a statistical significant decrease on Ca, and Ca/P ratios (At%) values after bleaching compared to baseline, followed by a significant increase after treatment with all tested remineralizing gels. SEM photomicrograph of sound enamel shows smooth uniform appearance with few pores. Bleached enamel showed irregular pitted disorganized enamel surface. Bleached enamel exposed to GSE and fluoride gel showed occlusion of enamel surface porosities and precipitates of different sizes. CONCLUSIONS: The specially prepared GSE hydrogels has positive effects on the remineralization process of bleached enamel making it an effective natural agent with remineralizing potential. Key words:Remineralization, bleaching, grape seed extract, fluoride, enamel.

Transdermal microemulsions of Glycyrrhiza glabra L.: characterization, stability and evaluation of antioxidant potential.

The purpose of the present study is to formulate Glycyrrhiza glabra root and rhizome aqueous ethanolic extract in microemulsion carrier systems intended for transdermal delivery of incorporated antioxidant actives, flavonoids and polyphenols. The results obtained reveal that the microemulsion system ME3 possesses optimum properties regarding drug content (flavonoids and polyphenols), viscosity, pH, particle size and polydispersity index, zeta potential, stability, permeation of actives and hence possesses high in vitro and ex vivo antioxidant efficacy. These results indicate also that this microemulsion shows approximately 13-fold higher ex vivo antioxidant capacity compared with the liquorice extract solution. In addition, the proposed microemulsion is simple to dispense, cost effective and provides high patient compliance and convenience because of simple topical application and avoidance of non-comfortable oral or parenteral administration.