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Polihydroksyalkanolany - obiecujące polimery biodegradowalne

100%

Mizielińska M., Łopusiewicz Ł., Soból M.

Kosmos

2018

vol. 67

issue 2

299-306

W pracy omówiono polihydroksyalkanolany, biopolimery o ogromnym potencjale. Scharakteryzowano ich właściwości i zastosowanie, zwracając uwagę na takie ich zalety jak biozgodność (brak toksyczności w stosunku do organizmu), podatność na biodegradację, czy właściwości termoplastyczne, zbliżone do tworzyw sztucznych. Niestety, pomimo wielu zalet, PHA nie są powszechnie wykorzystywane, głównie ze względu na wysoki koszt ich wytwarzania i oczyszczania. Dlatego w celu obniżenia kosztów podejmuje się działania w kierunku zastąpienia podczas hodowli drobnoustrojów źródła węgla tanimi materiałami odpadowymi. Kolejnym sposobem zmniejszenia kosztów produkcji PHA jest wykorzystanie modyfikowanych genetycznie mikroorganizmów. Alternatywą może być także poszukiwanie nowych metod wyodrębniania biopolimeru z komórek. Dobrym pomysłem może być także łączenie chemicznych i mechanicznych metod oczyszczania PHA. PHA bardzo często wykorzystywane są w medycynie, zastępując tworzywa sztuczne, gdzie istotne są właściwości materiałów oraz ich podatność na biodegradację. Niestety, ze względu na cenę, do wytwarzania polimerowych przedmiotów użytku codziennego, polimery syntetyczne wykorzystywane są częściej.

This paper discusses properties of polyhydroxyalkanoates (PHA), biopolymers with a huge potential for practical applications. PHA have a number of advantages such as biocompatibility (no toxicity for organism), biodegradability and thermoplastic properties similar to those of synthetic plastics. Unfortunately, despite these advantages PHA are not widely used owing to the high costs of their preparation and purification. Therefore, in order to reduce these costs efforts are being undertaken to replace traditional carbon sources for cultivation of microorganisms by cheaper waste materials. Another way to reduce the cost of PHA production is the use of genetically modified microorganisms. An alternative approach may be also a search for new methods for extraction of these biopolymer from the cells including combination of chemical and mechanical methods of purification. PHA are very often used in medicine, because of their properties and biodegradability. In this area they substitute plastics. Unfortunately, costs of production from PHA polymeric objects for everyday use are still too high, so synthetic polymers remain predominantly in use.

ENCAPSULATION OF ROXITHROMYCIN INTO GELLAN GUM MATRICES AND THE IMPACT OF OTHER NATURAL POLYMERS ON DRUG RELEASE

76%

Gadziński P., Froelich A., Kowalska U., Soból M., Szybowicz M., Osmałek T.

Acta Poloniae Pharmaceutica - Drug Research

2020

vol. 77

issue 2

319-330

The aim of the work was to investigate the properties of polysaccharide matrices loaded with roxithromycin (ROX), made on the basis of low-acyl gellan and its blends with sodium alginate, pectin, karaya gum, methycellulose and κ-carageenan. The obtained formulations were investigated as potential oral dosage forms with the ability to protect it from the acidic conditions of the stomach. Another desired feature of the obtained systems was the sustained release of the active ingredient allowing for potential shifting the therapeutic effect to the colon. The morphology of the matrices was evaluated with optical and scanning electron microscopy. Moreover, Raman spectroscopy and thermal analysis were performed for ROX, polymers, ROX/polymers physical mixtures and the matrices. Next, the swelling behavior was examined. The matrices were evaluated for ROX content and encapsulation efficiency. The last stage concerned the drug release studies. All matrices after production revealed more or less oval shape with visible deformation most probably occurring during drying. Raman analysis and DSC confirmed the crystalline form of ROX and showed no evidence of interactions between the drug and the excipients. It was shown that the matrices containing gellan combined with methylcellulose or κ-carageenan at pH=7.4 released ROX slower than the other matrices which might be promising in terms of colonic drug delivery. Moreover, the polymer matrices remained physically stable at acidic pH similar to the environment of the stomach. However, in these conditions drug degradation was observed which indicates the necessity to further modify the applied technology.

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1 Acta Poloniae Pharmaceutica - Drug Research

1 Kosmos

1 2020

1 2018

2 Soból M.

1 Froelich A.

1 Gadziński P.

1 Kowalska U.

1 Mizielińska M.

1 Osmałek T.

1 Szybowicz M.

1 Łopusiewicz Ł.

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Polihydroksyalkanolany - obiecujące polimery biodegradowalne

ENCAPSULATION OF ROXITHROMYCIN INTO GELLAN GUM MATRICES AND THE IMPACT OF OTHER NATURAL POLYMERS ON DRUG RELEASE