European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences
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Ropivacaine (RVC) is an enantiomerically pure local anesthetic (LA) largely used in surgical procedures, which presents physico-chemical and therapeutic properties similar to those of bupivacaine (BPV), but associated to less systemic toxicity. This study focuses on the development and pharmacological evaluation of a RVC in 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) inclusion complex. Phase-solubility diagrams allowed the determination of the association constant between RVC and HP-beta-CD (9.46 M(-1)) and showed an increase on RVC solubility upon complexation. ⋯ Nuclear magnetic resonance (NMR) and job-plot experiments afforded data regarding inclusion complex stoichiometry (1:1) and topology. Sciatic nerve blockade studies showed that RVC HP-beta-CD was able to reduce the latency without increasing the duration of motor blockade, but prolonging the duration and intensity of the sensory blockade (p<0.001) induced by the LA in mice. These results identify the RVC HP-beta-CD complex as an effective novel approach to enhance the pharmacological effects of RVC, presenting it as a promising new anesthetic formulation.
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Tanshinone II(A) and cryptotanshinone are the main pharmacologically active components in the Chinese herb drug Salvia miltiorrhiza Bge. The objective of this study was to investigate the effect of coexisting tanshinones in liposoluble ethanol extract of S. miltiorrhiza Bge. on the rat pharmacokinetics of tanshinone II(A) and cryptotanshinone after oral intra-gavage administration of the tanshinones extract. Rats were given the tanshinones extract 23.3 mg/kg (equivalent to 5.7 mg/kg cryptotanshinone and 8.0mg/kg tanshinone II(A)), cryptotanshinone 5.7 mg/kg, or tanshinone II(A) 8.0 mg/kg orally under overnight fasted conditions. ⋯ Tanshinone II(A) was also found after the administration of cryptotanshinone alone, and the fraction of metabolism of tanshinone II(A) was 21.0+/-4.1%. Therefore, the pharmacokinetics of cryptotanshinone and tanshinone II(A) in rats after administration of the tanshinones extract were significantly affected by the coexisting tanshinones. In conclusion, the herb-drug interactions occurred between coexisting tanshinones and cryptotanshinone or tanshinone II(A) affected their absorption, transformation and metabolism.
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Insulin-loaded alginate microspheres prepared by emulsification/internal gelation were reinforced by blending with polyanionic additive polymers and/or chitosan-coating in order to increase the protection of insulin at simulated gastric pH and obtain a sustained release at simulated intestinal pH. Polyanionic additive polymers blended with alginate were cellulose acetate phtalate (CAP), Eudragit L100 (EL100), sodium carboxymethylcellulose (CMC), polyphosphate (PP), dextran sulfate (DS) and cellulose sulfate (CS). Chitosan-coating was applied by using a one-stage procedure. ⋯ Insulin release, at pH 1.2, was almost prevented by the incorporation of PP, DS and CS. When uncoated microspheres were transferred to pH 6.8, a fast dissolution occurred, independently of the additive polymer blended with alginate, and insulin was completely released. Increasing the additive polymer concentration in the alginate matrix and/or chitosan-coating the blended alginate microspheres did not promote a sustained release of insulin from microspheres at pH 6.8.
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Type 2 diabetes mellitus is a major and growing health problem throughout the world. Current treatment approaches include diet, exercise, and a variety of pharmacological agents including insulin, biguanides, sulfonylureas and thiazolidinediones. New therapies are still needed to control metabolic abnormalities, and also to preserve beta-cell mass and to prevent loss of beta-cell function. ⋯ However, both the strategies are having their own advantages and limitations. The present review summarizes the concepts of GLP-1 based therapy for type 2 diabetes and the current preclinical and clinical development in GLP-1 mimetics and DPP-IV inhibitors. Further, the potential advantages and the limitations of both the strategies are discussed.
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Transporters play an important role in the processes of drug absorption, distribution and excretion. In this review, we have focused on the involvement of transporters in drug excretion in the liver and kidney. The rate of transporter-mediated uptake and efflux determines the rate of renal and hepatobiliary elimination. ⋯ More recently, some methods to analyze such transporter-mediated transport have been reported. The estimation of the contributions of transporters to the net clearance of a drug makes it possible to predict the net clearance from data involving drug transport in transporter-expressing cells. Double transfected cells, where both uptake and efflux transporters are expressed on the same polarized cells, are also helpful for the analysis of the rate of transporter-mediated transcellular transport.