Drug delivery from catalysed erodible polymeric matrices of poly(ortho ester)s

Shih, Chung; Higuchi, Takeru; Himmelstein, Kenneth J.

doi:10.1016/0142-9612(84)90022-x

Cited by 59 publications

(17 citation statements)

References 7 publications

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“…POEs widely used are in the drug delivery application. The first POE, POE I, generates carboxylic acid upon hydrolysis which then further catalyzes the acid-sensitive cleavage [83][84]. Basic salt such as Na 2 CO 3 or Mg(OH) 2 is generally added to neutralize the acid product, but this can be the cause of the limited diffusion system which shows non zero-order drug release characteristics [85].…”

Section: Poly (Ortho Esters) (Poes)mentioning

confidence: 99%

A review on biodegradable materials for cardiovascular stent application

Hou

Pan

et al. 2016

Front. Mater. Sci.

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A stent is a medical device designed to serve as a temporary or permanent internal scaffold to maintain or increase the lumen of a body conduit. The researchers and engineers diverted to investigate biodegradable materials due to the limitation of metallic materials in stent application such as stent restenosis which requires prolonged anti platelet therapy, often result in smaller lumen after implantation and obstruct re-stenting treatments. Biomedical implants with temporary function for the vascular intervention are extensively studied in recent years. The rationale for biodegradable stent is to provide the support for the vessel in predicted period of time and then degrading into biocompatible constituent. The degradation of stent makes the re-stenting possible after several months and also ameliorates the vessel wall quality. The present article focuses on the biodegradable materials for the cardiovascular stent. The objective of this review is to describe the possible biodegradable materials for stent and their properties such as design criteria, degradation behavior, drawbacks and advantages with their recent clinical and preclinical trials.

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Section: Poly (Ortho Esters) (Poes)mentioning

confidence: 99%

A review on biodegradable materials for cardiovascular stent application

Hou

Pan

et al. 2016

Front. Mater. Sci.

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“…10 Pharmacological manipulation of tissues after some surgeries determines the success of the procedures performed. 11 This is especially true in reconstructive surgery for tissues which are vascularly compromised.…”

Section: à10mentioning

confidence: 99%

Effect of long‐term application of epinephrine on rat skin vasculature: Experimental study

et al. 2002

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As a potent vasoconstrictor, epinephrine is used ubiquitously in plastic surgery. It is typically delivered subcutaneously in very low concentrations over a brief time interval. We are aware of no reports describing the long-term release of epinephrine as an independent agent to the soft tissues for the purpose of causing prolonged local vasoconstriction. This study was designed to address two goals: first, to investigate the effect of long-term local release of epinephrine from a drug delivery system on rat abdominal skin vasculature; secondly, to evaluate the pharmacological properties of this drug delivery system (DDS). Thirty male Sprague-Dawley rats, weighing 300-400 g, were included in the study. Animals were subdivided into two groups of 15 each. Group A (control group) and Group B (experimental group) were treated with saline and epinephrine-loaded microspheres (msps), respectively. The manufacturing process and formulation studies of the DDS are described. In vivo assays revealed a 7-day sustained release of epinephrine. After 7 days, neither residual nor supraphysiologic release of epinephrine was shown with high-performance liquid chromatography (HPLC). Histological studies with hematoxylin-eosin and periodic acid Schiff revealed a statistically significant increase in number of vessels as well as their diameter and wall thickness (P <0.05). Epinephrine release via this msp/DDS predictably induces local vasoconstriction over a time sequence known to be optimally associated with hypoxia and promotion of vascular augmentation. This model can be valuable in sustaining hemostasis during long-lasting (more than a few hours) surgical procedures by its long-acting vasoconstructive effect. The system's ability to intentionally cause vascular augmentation also bodes great potential in flap and graft surgery.

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“…Matrix systems, prepared by uniform dispersion of drug particles throughout a solid nonerodible polymer (4). Matrix systems, prepared by uniform dispersion of drug particles throughout a solid nonerodible polymer (4).…”

Section: Introductionmentioning

confidence: 99%

Study of biopolymers as carriers for controlled release

Andreopoulos

Tarantili

2002

Journal of Macromolecular Science, Part B

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An attempt was made to compare swelling and release behavior of two polysaccharides, xanthan gum (XG) and hydroxypropylmethyl cellulose (HPMC), taking into consideration their dissolution characteristics. This study was expected to provide information about the capability of these polymers to satisfy specific requirements in the design of controlled release systems. Tablets were prepared from the pure polymers as well as by using mixtures of XG and HPMC containing 1, 2, and 5% salicylic acid (SA) as a model drug. Swelling and dissolution experiments were run and the release in distilled water was recorded as a function of time. The results showed that XG and HPMC are very interesting matrices for the preparation of controlled release systems. Complete administration of SA in concentrations from 1 to 5% takes place within about 10 hr for XG, whereas approximately 5 days are necessary for the same result in the case of HPMC tablets. For both systems, nonFickian behavior was recorded with the diffusion exponent ranging from 0.67 to 0.78. Upon fitting the release data to the Peppas and Sahlin heuristic model, it was clear that, in general, erosion was the predominant factor for SA release from XG tablets, whereas the acid delivery from HPMC mainly proceeds via Fickian diffusion. These results seemed to be dependent on the water solubility of the released substance.

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Drug delivery from catalysed erodible polymeric matrices of poly(ortho ester)s

Cited by 59 publications

References 7 publications

A review on biodegradable materials for cardiovascular stent application

A review on biodegradable materials for cardiovascular stent application

Effect of long‐term application of epinephrine on rat skin vasculature: Experimental study

Study of biopolymers as carriers for controlled release

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