Sorpcija diklofenaka na selektivno oksidovanu celulozu / SORPTION OF DICLOFENAC TO SELECTIVELY OXIDISED CELLULOSE

• Published in: Hemijska industrija Vol. 72; no. 3; p. 167
• Main Authors: Sailovic, Pero S, Rodic Grabovac, Branka B, Uletilovic, Snezana M
• Format: Journal Article
• Language: English
• Published: Association of Chemical Engineers of Serbia 01.05.2018
• Subjects: Cellulose; Chemical properties; Diclofenac; Observations; Sorption
• ISSN: 0367-598X
• DOI: 10.2298/HEMIND180119010S

Vezivanje ljekovitih preparata na polimerne nosace odredeno je vrstom nosaca i strukturom samog lijeka. U ovom radu kao polimerni nosac korištena je selektivno oksidovana celuloza (OC) sa 0,547 i 1,163 mmol/g COOH. Dobijena je oksidacijom celuloznog zavoja smjesom HN[O.sub.3]-[H.sub.3]P[O.sub.4]-NaN[O.sub.2] u trajanju od 5 i 10 casova na temperaturi 25[+ or -]1 [degrees]C, i upotrebljena je za vezivanje analgetika diklofenak-kalijuma. Vezivanje lijeka vršeno je iz vodenog rastvora koncentracija c = 2,5*[10.sup.-3], 3,4*[10.sup.-3] i 5,1*[10.sup.-3] mol/L na temperaturi 26[+ or -]1 [degrees]C, a desorpcija analgetika u fiziološkom rastvoru. Kolicine vezanog i otpuštenog lijeka odredene su spektrofotometrijski na talasnoj dužini od [[lambda].sub.max] = 276 nm. Maksimalna kolicina vezanog lijeka nakon 24 h iznosila je 0,814 mmol/g OC (iz rastvora c = 5,1*[10.sup.-3] mol/L, na uzorku sa 1,163 mmol/g COOH), a maksimalna kolicina desorbovanog lijeka 0,063 mmol/g OC (nakon 24 h u fiziološkom rastvoru, uzorak sa 1,163 mmol/g COOH). U radu se proucava uticaj sadržaja COOH grupa i sorpcionih svojstava OC, kao i uticaj hemijske strukture diklofenaka, pH vrijednosti rastvora i trajanja sorpcije na kolicinu vezanog lijeka. Takode, ispitana je i prekidna jacina oksidovanih celuloznih vlakana. Ustanovljeno je da se vezivanje lijeka ostvaruje pretežno vodonicnim vezama. Kljucne reci: oksidovana celuloza, diklofenak-K, hemizam vezivanja, biološki aktivno analgetsko vlakno. Biologically active fibers as drug carriers have improved characteristics in comparison with conventional medical therapies. Cellulose as a hydrophilic and biocompatible, nontoxic and eco-friendly material, makes a good polymer matrix for obtaining biologically active fibers. Loading drugs on the fiber carrier is accomplished through hydrophobic interactions, which is a prevailing mechanism of drug bonding. These interactions can be achieved by hydrophobic parts of the drug and the fiber carrier or by hydrophobic drugs themselves bonded on the fiber. In this paper, oxidized cellulose (OC) with 0.547, 1.163 and 2.199 mmol/g COOH is produced by using selective oxidation of a cellulose-based bandage. Oxidation has been carried out in mixture of HNO3/H3PO4 2:1 and 1.43 % NaNO2 for 5, 10 and 20 h at 25 [+ or -] 1 [degrees]C. The OC sample with 2.199 mmol/g COOH showed the lowest sorption capacity as well as weak mechanical properties, so that the sorption experiments were not further pursued. The other two samples of oxidized cellulose with 0.547 and 1.163 mmol/g COOH have been used for chemical bonding of an analgesic, diclofenac, a derivative of potassium salt. Diclofenac in its structure contains two benzene rings which are linked via a secondary amine. The analgesic also contains a carboxyl group, as well as 2 chlorine atoms. As a result of the presence of these functional groups and structures, diclofenac can build multiple chemical bonds with an oxidized cellulose bandage. The chemical bonding of the drug has been performed using three analgesic solutions with concentrations of c = 2.5*10-3, 3.4*10-3 and 5.1*10-3 mol/L, at the temperature of 26 [+ or -] 1 [degrees]C while desorption was performed in physiological saline solution. The amounts of bonded and released antibiotic were determined by UV-VIS spectroscopy at the wavelength of [[lambda].sub.max]=276 nm. The maximum amount of bonded drug (0.814 mmol/g OC) has been obtained by sorption from the solution of concentration c=5.1*10-3, while the highest amount of desorbed diclofenac was 0.063 mmol/g OC. The sorption kinetics has been succesfully described by the pseudo-second order model. It was established that the drug bonding was achieved by hydrogen bonds of the drug functional groups with the oxidised cellulose bandage. Low diclofenac relase from the oxsidiesed cellulose (12.5 % in 24 h) is a consequence of formation of multiple bond as well as drug aggregates on fiber surfaces. Keywords: oxidised cellulose * diclofenac-K * chemism of binding * biologically active analgetic fiber