A pharmaceutical answer to nonadherence: Once weekly oral memantine for Alzheimer's disease.

Adherence to medication regimens is a major barrier to effective treatment in many disease areas, notably in dementia which causes cognitive impairment that reduces patients' awareness of non-adherence and their ability to manage medication. The development of oral dosage forms that can be infrequently dosed, and therefore improve adherence rate and facilitate direct observed therapy, has been a goal for decades. We describe the first demonstration of an oral formulation that achieves >7-day gastric retention and sustained pharmacokinetics in the challenging dog model.

In vivo and in vitro characterization of poly(styrene-b-isobutylene-b-styrene) copolymer stent coatings for biostability, vascular compatibility and mechanical integrity.

The TAXUS Express 2 Paclitaxel Eluting Coronary Stent System employs a coating consisting of the thermoplastic elastomer, poly(styrene-b-isobutylene-b-styrene; SIBS), selected for its drug-eluting characteristics, vascular compatibility, mechanical properties, and biostability. This study was conducted to evaluate the impact of different SIBS (17-51 mole % styrene) compositions on mechanical properties, chemical stability, and vascular compatibility. Mechanical property (stress-strain measurements) and stability studies were conducted on polymer films with five different styrene contents (17, 24, 32, 39, and 51 mole %).

In vitro and in vivo evaluation of the safety and stability of the TAXUS Paclitaxel-Eluting Coronary Stent.

Functional aspects of the styrene-b-isobutylene-b-styrene triblock copolymer (SIBS) which is incorporated into a drug-eluting stent (DES) coating are described. The SIBS copolymer is employed on the TAXUS Paclitaxel-Eluting Coronary Stent as a carrier for paclitaxel (PTx). Optical and scanning electron microscopic analysis of stents explanted from rabbit and porcine models after 2 years and 6 months, respectively, showed that the SIBS coating maintained physical integrity.

Controlled delivery of paclitaxel from stent coatings using novel styrene maleic anhydride copolymer formulations.

The controlled release of paclitaxel (PTx) from stent coatings comprising an elastomeric polymer blended with a styrene maleic anhydride (SMA) copolymer is described. The coated stents were characterized for morphology by scanning electron microscopy (SEM) and atomic force microscopy (AFM), and for drug release using high-performance liquid chromatography (HPLC). Differential scanning calorimetry (DSC) was used to measure the extent of interaction between the PTx and polymers in the formulation.

Synthesis, characterization, properties, and drug release of poly(alkyl methacrylate-b-isobutylene-b-alkyl methacrylate).

Polyisobutylene (PIB)-based block copolymers have attracted significant interest as biomaterials. Poly(styrene-b-isobutylene-b-styrene) (SIBS) has been shown to be vascularly compatible and, when loaded with paclitaxel (PTx) and coated on a coronary stent, has the ability to deliver the drug directly to arterial walls. Modulation of drug release from this polymer has been achieved by varying the drug/polymer ratio, by blending SIBS with other polymers, and by derivatizing the styrene end blocks to vary the hydrophilicity of the copolymer.

Evaluation of acrylate-based block copolymers prepared by atom transfer radical polymerization as matrices for paclitaxel delivery from coronary stents.

Acrylate-based block copolymers, synthesized by atom transfer radical polymerization (ATRP) processes, were evaluated as drug delivery matrices for the controlled release of paclitaxel from coronary stents. The polymers were multiblock copolymers consisting of poly(butyl acrylate) or poly(lauryl acrylate) soft blocks and hard blocks composed of poly(methyl methacrylate), poly(isobornyl acrylate), or poly(styrene) homo- or copolymers. Depending on the ratio of hard to soft blocks in the copolymers, coating formulations were produced that possessed variable elastomeric properties, resulting in stent coatings that maintained their integrity when assessed by scanning electron microscopy (SEM) imaging of overexpanded stents.

Controlled delivery of paclitaxel from stent coatings using poly(hydroxystyrene-b-isobutylene-b-hydroxystyrene) and its acetylated derivative.

A poly(styrene-b-isobutylene-b-styrene) (SIBS) triblock polymer is employed as the polymer drug carrier for the TAXUS Express2 Paclitaxel-Eluting Coronary Stent system (Boston Scientific Corp.). It has been shown that the release of paclitaxel (PTx) from SIBS can be modulated by modification of either drug-loading ratio or altering the triblock morphology by blending.