Macromolecular Prodrugs of Ribavirin Combat Side Effects and Toxicity With No Loss of Activity of the Drug.

Macromolecular prodrugs of ribavirin combat side effects and toxicity with no loss of activity of the drug.

Chem Commun (Camb). 2013 Feb 22;
Kryger MB, Wohl BM, Smith AA, Zelikin AN

Chemi-enzymatic synthesis of ribavirin acrylate and subsequent RAFT co-polymerization with acrylic acid afforded a formulation of a broad spectrum antiviral drug which avoids accumulation in erythrocytes, the origin of the main side effect of ribavirin. In cultured macrophages the macromolecular prodrugs exhibited decreased toxicity while maintaining the anti-inflammatory action of ribavirin. HubMed – drug

Parametric Signal Fitting by Gaussian Peak Adjustment: implementation of 2D transversal constraints and its application for the determination of pK(a) and complexation constants by differential pulse voltammetry.

Analyst. 2013 Feb 21;
Cavanillas S, Serrano N, Díaz-Cruz JM, Ariño C, Esteban M

A new method, GPA2D, is presented as a significant improvement of the previously described Gaussian Peak Adjustment (GPA) which includes, for the first time, transversal constraints to increase the consistency of the resolution along the different signals of a voltammetric dataset. The constraints deal with the evolution of peak potentials versus pH and with the implementation of chemical equilibrium constants. Moreover, pkavolt, a new tool for the pK(a) determination, is proposed as an example of the great versatility of the PSF-GPA (Parametric Signal Fitting by Gaussian Peak Adjustment) methodology. GPA2D and pkavolt have been successfully tested on the systems Cd(ii):phytochelatin, Cu(ii):6-benzylaminopurine, Cd(ii):1,10-phenanthroline, Zn(ii):oxalate and captopril drug by determining formation constants (metal complex systems) or pK(a) values (captopril). HubMed – drug

Design and development of novel dual-compartment capsule for improved gastroretention.

ISRN Pharm. 2013; 2013: 752471
Patil GB, Singh SS, Ramani KP, Chatap VK, Deshmukh PK

The aim of the proposed research work was to develop a novel dual-compartment capsule (NDCC) with polymeric disc for gastroretentive dosage form, which will ultimately result in better solubility and bioavailability of Ofloxacin. Floating ring caps were formulated by using different natural polymers, separating ring band and swellable polymer located at the bottom of capsule. Formulated ring caps were assessed for coating thickness, In vitro buoyancy, In vitro drug release, release kinetics and stability studies. Coating attained by the capsule shell was found to be 0.0643?mm. Depending on nature of natural polymer used, most of the formulations showed buoyancy for more than 9 hrs. Developed formulation demonstrated considerably higher drug release up to 9 hrs. The developed formulation F(E2) depicted the drug release according to Korsmeyer-Peppas model. There was not any significant change in performance characteristics of developed ring caps after subjecting them to stability studies. The present study suggests that the use of NDCC for oral delivery of Ofloxacin could be an alternative to improve its systemic availability which could be regulated by the floating approach. The designed dosage system can have futuristic applications over payloads which require stomach-specific delivery. HubMed – drug

MicroRNAs and Glucocorticoid-Induced Apoptosis in Lymphoid Malignancies.

ISRN Hematol. 2013; 2013: 348212
Sionov RV

The initial response of lymphoid malignancies to glucocorticoids (GCs) is a critical parameter predicting successful treatment. Although being known as a strong inducer of apoptosis in lymphoid cells for almost a century, the signaling pathways regulating the susceptibility of the cells to GCs are only partly revealed. There is still a need to develop clinical tests that can predict the outcome of GC therapy. In this paper, I discuss important parameters modulating the pro-apoptotic effects of GCs, with a specific emphasis on the microRNA world comprised of small players with big impacts. The journey through the multifaceted complexity of GC-induced apoptosis brings forth explanations for the differential treatment response and raises potential strategies for overcoming drug resistance. HubMed – drug

Tumor-specific expression of organic anion-transporting polypeptides: transporters as novel targets for cancer therapy.

J Drug Deliv. 2013; 2013: 863539
Buxhofer-Ausch V, Secky L, Wlcek K, Svoboda M, Kounnis V, Briasoulis E, Tzakos AG, Jaeger W, Thalhammer T

Members of the organic anion transporter family (OATP) mediate the transmembrane uptake of clinical important drugs and hormones thereby affecting drug disposition and tissue penetration. Particularly OATP subfamily 1 is known to mediate the cellular uptake of anticancer drugs (e.g., methotrexate, derivatives of taxol and camptothecin, flavopiridol, and imatinib). Tissue-specific expression was shown for OATP1B1/OATP1B3 in liver, OATP4C1 in kidney, and OATP6A1 in testis, while other OATPs, for example, OATP4A1, are expressed in multiple cells and organs. Many different tumor entities show an altered expression of OATPs. OATP1B1/OATP1B3 are downregulated in liver tumors, but highly expressed in cancers in the gastrointestinal tract, breast, prostate, and lung. Similarly, testis-specific OATP6A1 is expressed in cancers in the lung, brain, and bladder. Due to their presence in various cancer tissues and their limited expression in normal tissues, OATP1B1, OATP1B3, and OATP6A1 could be a target for tumor immunotherapy. Otherwise, high levels of ubiquitous expressed OATP4A1 are found in colorectal cancers and their metastases. Therefore, this OATP might serve as biomarkers for these tumors. Expression of OATP is regulated by nuclear receptors, inflammatory cytokines, tissue factors, and also posttranslational modifications of the proteins. Through these processes, the distribution of the transporter in the tissue will be altered, and a shift from the plasma membrane to cytoplasmic compartments is possible. It will modify OATP uptake properties and, subsequently, change intracellular concentrations of drugs, hormones, and various other OATP substrates. Therefore, screening tumors for OATP expression before therapy should lead to an OATP-targeted therapy with higher efficacy and decreased side effects. HubMed – drug