RESUMEN
Hyaluronic acid (HA) is a natural ligand of tumor-targeted drug delivery systems (DDS) due to the relevant CD44 receptor overexpressed on tumor cell membranes. However, other HA receptors (HARE and LYVE-1) are also overexpressing in the reticuloendothelial system (RES). Therefore, polyethylene glycol (PEG) modification of HA-based DDS is necessary to reduce RES capture. Unfortunately, pegylation remarkably inhibits tumor cellular uptake and endosomal escapement, significantly compromising the antitumor efficacy. Herein, we developed a Dox-loaded HA-based transformable supramolecular nanoplatform (Dox/HCVBP) to overcome this dilemma. Dox/HCVBP contains a tumor extracellular acidity-sensitive detachable PEG shell achieved by a benzoic imine linkage. The and investigations further demonstrated that Dox/HCVBP could be in a "stealth" state at blood stream for a long circulation time due to the buried HA ligands and the minimized nonspecific interaction by PEG shell. However, it could transform into a "recognition" state under the tumor acidic microenvironment for efficient tumor cellular uptake due to the direct exposure of active targeting ligand HA following PEG shell detachment. Such a transformative concept provides a promising strategy to resolve the dilemma of natural ligand-based DDS with conflicting two processes of tumor cellular uptake and nonspecific biodistribution.
RESUMEN
Objective: To establish a GC method for the determination of content and content uniformity of memantine hydrochloride dispersible tablets.Methods: The sample was dissolved in water, alkalified by sodium hydroxide solution and extracted by methylene chloride.An HP-5 gas chromatography column (50 m×0.32 mm, 1.05 μm) was used.The column temperature was programming increased, and the initial temperature maintained at 120 ℃ for 3 min, and then raised to 220 ℃ at a rate of 10℃·min-1 and maintained for 7 min.A hydrogen flame ionization detector (FID) was used and the split ratio was 1∶1.The inlet temperature was 230 ℃ and the detector temperature was 260 ℃.The injection volume was 1 μl and the carrier gas was nitrogen with high purity at a flow rate of 3.0 ml·min-1.Adamantane was used as the internal standard, and the internal standard method was used for the calculation.Results: The calibration curve was linear over the range of 0.05-1.0 mg·ml -1 (r=0.999 7).The detection limit and the limit of quantification was 1.1 ng and 3.3 ng, respectively.The average recovery was 100.2% (RSD =0.73%, n=9).Conclusion: The method has the advantages of simple operation, small extraction process toxicity, little environmental pollution, high accuracy and high specificity, and can be used for the determination of content and content uniformity of memantine hydrochloride dispersible tablets.
RESUMEN
Background: Vildagliptin is a dipeptidyl peptidase IV inhibitor (DPP4i). Its efficacy and safety of DPP4i in Chilean real life type 2 diabetic (T2D) patients is not well known. Aim: To assess the safety profile and effectiveness of 12 weeks of treatment with Vildagliptin for glycemic control in T2D Chilean patients with a poor glycemic control. Patients and Methods: Retrospective assessment of the effects of Vildagliptin treatment during 12 weeks in 103 T2D patients aged 29 to 92 years (47% males). The main outcomes were changes in glycosylated hemoglobin and the occurrence of adverse effects. Results: After 12 weeks of Vildagliptin use, glycosylated hemoglobin decreased from 8.3 ± 1.4 to 7.2 ± 1.1% (p < 0.01). Fasting plasma glucose and the number of hypoglycemic events also decreased significantly. No significant weight change was observed. The treatment had good compliance, tolerance and patient satisfaction. Conclusions: Vildagliptin treatment reduced glycosylated hemoglobin by 1.1% and was well tolerated in this group of diabetic patients.