Polymer hydrogel-based microneedles for metformin release

Drug delivery devices ensure the effective delivery of a broad range of therapeutics to millions of patients worldwide on a daily basis.1 Microneedles are a class of drug delivery device that provide pain free transdermal delivery with improved patient compliance.2-4 The release of metformin, a drug used in the treatment of cancer and diabetes, from polymer hydrogel-based microneedle patches was demonstrated in vitro. Tuning the composition of the polymer hydrogels enabled preparation of robust microneedle patches with mechanical properties such that they would penetrate skin (insertion force of a single microneedle to be ca. 40 N). Swelling experiments conducted at 20°C, 35°C and 60°C show temperature dependent degrees of swelling and kinetics (Fickian diffusion). Drug release from the hydrogel-based microneedles was fitted to various models (e.g., zero order, first order, second order, Korsmeyer-Peppas, Peppas-Sahlins), observing the best fit for the zero-order model. Such microneedles have potential application for transdermal delivery of metformin for the treatment of cancer and diabetes

Poly(2-Hydroxyethyl Methacrylate) Hydrogel-Based Microneedles for Metformin Release

The release of metformin, a drug used in the treatment of cancer and diabetes, from poly(2-hydroxyethyl methacrylate), pHEMA, hydrogel-based microneedle patches is demonstrated in vitro. Tuning the composition of the pHEMA hydrogels enables preparation of robust microneedle patches with mechanical properties such that they would penetrate skin (insertion force of a single microneedle to be ≈40 N). Swelling experiments conducted at 20, 35, and 60 °C show temperature-dependent degrees of swelling and diffusion kinetics. Drug release from the pHEMA hydrogel-based microneedles is fitted to various models (e.g., zero order, first order, second order). Such pHEMA microneedles have potential application for transdermal delivery of metformin for the treatment of aging, cancer, diabetes, etc

A practical synthesis of 1,3-disubstituted cubane derivatives †

A robust multigram-scale synthesis of 1,3-disubstituted cubanes (previously only available on milligram-scale) is reported. The approach exploits a readily available enone intermediate previously used for the synthesis of 1,4-disubstituted cubanes, by introducing a novel Wharton transposition to access useful quantities of 1,3-disubstituted cubanes for diverse applications

Synthesis of Diverse Allylsilanes Employing Brønsted Acid Catalyzed Reductive Functionalization

We present a rapid (0.25‐1hr), method to produce functionalised allylsilanes from readily available vinylsilanes. Employing a Brønsted acid catalysed dehydration as the key step, allylsilanes are produced in good yields (22‐98%) and, in most cases, as a single geometric isomer. Furthermore, a possible alkylation‐Cope pathway was discovered for certain substrates and attempts to optimise this are described

Synthesis of diverse allylsilanes employing brønsted acid catalyzed reductive functionalization

We present a rapid (0.25–1 h), method to produce functionalised allylsilanes from readily available vinylsilanes. Employing a Brønsted acid catalysed dehydration as the key step, allylsilanes are produced in good yields (22–98%) and, in most cases, as a single geometric isomer. Furthermore, a possible allylation‐Cope pathway was discovered for certain substrates and attempts to optimise this are described