Anti-inflammatory drug encapsulation

An improvement of medical devices based on bacterial polymers by the encapsulation of different drugs, opens up the wide prospects in applications for these new devices with pharmacological activity in medicine. PHB polymer was used as a drug delivery matrix for sustaining the release of various drugs such as dipyridamole [DP], indomethacin and antibiotics (rifampicin, metronidazole, ciprofloxacin, levofloxacin), anti-inflammatory drugs (flurbiprofen, dexamethasone, prednisolone), and antitumor drugs (paclitaxel) [132]. 

Our group has recently reported on the preparation of PUR nanoparticles, based on poly(e-caprolactone) diol, 1,6-hexamethylene diisocyanate and aliphatic chain extenders, cyclohexanedimethanol and N-Boc serinol, for the encapsulation and release of the hydrophobic anti-cancer drug Paclitaxel (PX) and the anti-inflammatory drug Indomethacin (Mattu et al., 2013 Ferreira et al., 2014 Gentile et al., 2015a). Our studies showed the ability of PUR nanoparticles to encapsulate hydrophobic drugs and to extend their release as compared to commercial polymers. 

Encapsulation and delivery of anticancer, diabetes, psychotic, restenosis, tetanus, pulmonary, immunomodulatory agents [374], growth factors and hormones in PLGA nanoparticles has been reported [360,375]. They keep the ability to release the bioactive agent in a number of administration sites. PLGA microspheres have successfully incorporated nonsteroidal anti-inflammatory drugs for the treatment of arthritis and related diseases [376]. 

Chitosan microspheres containing sodium diclofenac, a nonsteroid antiinflammatory, were studied concerning the influence of Ca or AF ions on the microsphere morphology and the influence of different amounts of chitosan on the release of diclofenac [108]. Chitosan nanoparticles were PECylated and loaded with ibuprofen. This transformation increased the encapsulation efficiencies of the anti-inflammatory drug and the release of the drug was shown to be slower in the PECylated NPs than the normal chitosan NPs [109]. 

By encapsulation of the drug in liposomes a favourable alteration of the pharmacokinetics, as well as a lowered toxicity, may be obtained. Even more important is the fact that liposomes collect spontaneously in areas of inflammation and in tumour tissue. This property, which is believed to be due to the inherently leaky vasculature in these areas, has led to the development of several liposomal anti-inflammatory and anticancer agents. 

The encapsulation of hepatocytes for a bioartificial liver, and cell therapy for the treatment of other hormone deficiencies or neurodegenerative diseases, such as Alzheimer s and Parkinson s, are also under investigation. Additional examples of cell encapsulation in polymer-polymer coacervates include non-autologous gene therapy,blood substitutes as well as the treatment of prostate cancer. Pharmaceutical applications of microcapsules encompass, in addition, trans-dermal drug delivery and protein delivery such as is required in anti-inflammatory therapy for arthritis. 

Several anti-inflammatory dmgs were likely incorporated into such bead formulations of pectin providing satisfactory results of drug release [55], The pectin hydrogels are in addition adopted as a matrix for controlled dmg delivery, soft contact lenses, protein separation and matrices for cell encapsulation. 

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