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The objective of this study was to formulate extended-release mucoadhesive buccal tablets of propranolol hydrochloride in order to provide a prolonged absorption of propranolol hydrochloride from the buccal mucosa and to reduce presystemic metabolism and thus provide a better therapeutic effect. Besides, the aim was to perform comparative in vivo pharmacokinetic and hemodynamic studies of the developed extended-release (ER) propranolol hydrochloride 10 mg mucoadhesive buccal tablets and commercial immediate-release (IR) propranolol hydrochloride 10 mg tablets in spontaneously hypertensive rats. Formulation with 15% polyethylene oxide showed the highest degree of propranolol hydrochloride permeation, satisfactory mucoadhesiveness, and extended-release of propranolol hydrochloride, thus it was selected for further in vivo study. The pharmacokinetic study in rats showed the superiority of ER mucoadhesive buccal tablets over IR tablets in terms of propranolol hydrochloride absorption extent (AUC values: 70.32 ± 19.56 versus 31.69 ± 6.97 µg·h/mL), although lower maximum plasma propranolol hydrochloride concentration (Cmax) was achieved. However, no statistically significant difference was observed in Cmax between these treatments. The hemodynamic study showed that ER mucoadhesive buccal tablets provide a more pronounced decrease primarily in heart rate, but also in systolic and diastolic arterial pressure, as well as a longer heart rate reduction compared to IR tablets.

Antifungal agents are the group of drugs commonly prescribed in the treatment of fungal infections, which are widely spread among the global population. Their properties, such as absorption, distribution, metabolism, route of elimination or plasma protein binding (PPB), considerably influence their therapeutic success, while a number of the molecular physicochemical properties of the drug notably influence all these processes. Lipophilicity (log P), molecular weight (Mw), volume (Vol), polar surface area (PSA) and solubility (log S) play important roles in drug absorption, penetration into tis-sues, distribution and route of elimination or the degree of plasma protein bind-ing. In this study, the relationships between these five molecular properties of eight antifungal drugs and their plasma protein binding data obtained from relevant literature were investigated. The Selected physicochemical molecular descriptors of the drug were calculated using software packages. The estab-lished relationships between PPB and PSA; Mw; Vol and log S were showed relatively poor correlation (r < 0.35). The best correlation was obtained for the relationship between PPB data and the lipophilicity descriptor X log P3 (correlation coefficient r = 0.55). In further investigation, multiple linear reg-ression analysis was applied. The best correlation was obtained with applicat-ion of lipophilicity with polar surface area (r = 0.918) and volume (r = 0.916) or molecular weight (r = 0.896) as independent variables., Антифунгалнасредствапредстављајугрупулековакојисепримењујуулечењугљи-вичнихинфекција, данасширокораспрострањенихмеђуглобалномпопулацијом. Одњиховихособинакаоштосуапсорпција, дистрибуција, метаболизам, путелиминацијеиливезивањезапротеинеплазмe значајнозависињиховтерапеутскиуспех, абројнефизичко–хемијскеособинемолекулалекаутичунасвеовепроцесе. Липофилност(log P), молекулскамаса (Mw), запремина (Vol), поларнаповршина (PSA) ираствор-љивост (log S) играјуважнуулогууапсорпцијилека, продирањууткива, дистрибуцији, путуелиминацијеилистепенувезивањазапротеинеплазме. Уовомрадузаосаманти-фунгалнихлековаистраженисуодносиизмеђуособинамолекулаистепенањиховогвезивањазапротеинеплазме (PPB). Дескрипторифизичко–хемијскихособинамолекулаиспитиванихантифунгалнихлековаизрачунатисупомоћуодабранихсофтверскихпакета, доксуподациоњиховомPPBприкупљениизодговарајућелитературе. ОдносиизмеђуPPBиPSA, Mw, Volи log Sпоказалисулошукорелацију (r < 0,35) докјебољакорелацијадобијенајеизмеђуподатакаоPPBидеск рипторалипофилности, X log P3вредности (r = 0,55). Удаљемиспитивању, примењенајевишеструкалинеарнарегре-сионаанализа. НајбољезависностидобијенесуизмеђуPPBвредностиилипофилностиузприменуполарнеповршинемолекула (r = 0,918), волумена (r = 0,916) имолекулскемасе (r = 0,896) каонезависнопроменљивих.

Electrophoretic deposition process (EPD) was successfully used for obtaining graphene (Gr)-reinforced composite coating based on hydroxyapatite (HAP), chitosan (CS), and antibiotic gentamicin (Gent), from aqueous suspension. The deposition process was performed as a single step process at a constant voltage (5 V, deposition time 12 min) on pure titanium foils. The influence of graphene was examined through detailed physicochemical and biological characterization. Fourier transform infrared spectroscopy, field emission scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, Raman, and X-ray photoelectron analyses confirmed the formation of composite HAP/CS/Gr and HAP/CS/Gr/Gent coatings on Ti. Obtained coatings had porous, uniform, fracture-free surfaces, suggesting strong interfacial interaction between HAP, CS, and Gr. Large specific area of graphene enabled strong bonding with chitosan, acting as nanofiller throughout the polymer matrix. Gentamicin addition strongly improved the antibacterial activity of HAP/CS/Gr/Gent coating that was confirmed by antibacterial activity kinetics in suspension and agar diffusion testing, while results indicated more pronounced antibacterial effect againstStaphylococcus aureus(bactericidal, viable cells number reduction gt 3 logarithmic units) compared toEscherichia coli(bacteriostatic, lt 3 logarithmic units).MTT assay indicated low cytotoxicity (75% cell viability) against MRC-5 and L929 (70% cell viability) tested cell lines, indicating good biocompatibility of HAP/CS/Gr/Gent coating. Therefore, electrodeposited HAP/CS/Gr/Gent coating on Ti can be considered as a prospective material for bone tissue engineering as a hard tissue implant.

Electrophoretic deposition process (EPD) was successfully used for obtaining graphene (Gr)-reinforced composite coating based on hydroxyapatite (HAP), chitosan (CS), and antibiotic gentamicin (Gent), from aqueous suspension. The deposition process was performed as a single step process at a constant voltage (5 V, deposition time 12 min) on pure titanium foils. The influence of graphene was examined through detailed physicochemical and biological characterization. Fourier transform infrared spectroscopy, field emission scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, Raman, and X-ray photoelectron analyses confirmed the formation of composite HAP/CS/Gr and HAP/CS/Gr/Gent coatings on Ti. Obtained coatings had porous, uniform, fracture-free surfaces, suggesting strong interfacial interaction between HAP, CS, and Gr. Large specific area of graphene enabled strong bonding with chitosan, acting as nanofiller throughout the polymer matrix. Gentamicin addition strongly improved the antibacterial activity of HAP/CS/Gr/Gent coating that was confirmed by antibacterial activity kinetics in suspension and agar diffusion testing, while results indicated more pronounced antibacterial effect against Staphylococcus aureus (bactericidal, viable cells number reduction >3 logarithmic units) compared to Escherichia coli (bacteriostatic, <3 logarithmic units). MTT assay indicated low cytotoxicity (75% cell viability) against MRC-5 and L929 (70% cell viability) tested cell lines, indicating good biocompatibility of HAP/CS/Gr/Gent coating. Therefore, electrodeposited HAP/CS/Gr/Gent coating on Ti can be considered as a prospective material for bone tissue engineering as a hard tissue implant.

A simple and sensitive liquid chromatography-tandem mass spectrometry method was developed for the quantification of atorvastatin, ortho-hydroxyatorvastatin, para-hydroxyatorvastatin, and atorvastatin lactone in rat plasma. Solid-phase extraction was used for preparation of samples. Rosuvastatin was chosen as an internal standard. Chromatographic separation was achieved on ZORBAX Eclipse C-18 Analytical, 4.6 x 100 mm (3.5 mu m) column with a gradient mobile phase composed of acetonitrile and 0.1% acetic acid, at a flow rate of 400 mu L min(-1). The column was kept at constant temperature (25 degrees C), and autosampler tray temperature was set at 4 degrees C. The following selected reaction monitoring (SRM) transitions were selected: (m/z, Q1 -> Q3, collision energy) atorvastatin (559.47 -> 440.03, 22 eV), atorvastatin lactone (541.36 -> 448.02, 19 eV), orthohydroxyatorvastatin (575.20 -> 440.18, 20 eV), para-hydroxyatorvastatin (575.54 -> 440.18, 20 eV), and rosuvastatin (482.25 with selected combination of two fragments 257.77, 31 eV, and 299.81, 35 eV) in positive ion mode. The method was validated over a concentration range of 0.5-20 ng mL(-1) for ortho-hydroxyatorvastatin and para-hydroxyatorvastatin and 0.1-20 ng mL(-1) for atorvastatin and atorvastatin lactone with excellent linearity (r(2) >= 0.99). This method demonstrated acceptable precision and accuracy at four quality control concentration levels. The detection limits were 0.1 and 0.13 ng mL(-1) for orthohydroxyatorvastatin and para-hydroxyatorvastatin, respectively, and 0.05 ng mL(-1) for atorvastatin and atorvastatin lactone. All analytes were found to be stable at examined conditions. Validated method was applied for determination of atorvastatin and its metabolites in plasma of experimental animals.

Backgroung/Aim. Since combining conventional drugs with herbal medicinal products is in current research focus and possible of great interest as therapy improvement way, the aim of this study was to determine the effects of well-established antiatherosclerotic drug atorvastatin (CAS number 134523-00-5) and commercially available artichoke leaf tincture (ALTINC), used as combined therapy, as well as to compare effects of these two treatments separately. Methods. Experimental animals were divided into five groups: the group I (the control group of rats fed with standard diet during 11 weeks), and the remaining 4 groups of rats (II, III, IV and V) fed with standard diet during the first week and then with hypercholesterolemic diet during the next 10 weeks. The group II of rats were left without treatment, while in the groups III, IV and V were rats treated per os with atorvastatin (1.15 mg/kg body wright - b.w.), ALTINC (0.1 mL/kg b.w.) and their combination in same doses, respectively, for the last six weeks. Results. The cholesterol rich diet led to pronounced hyperlipidemia which could not be overcame with the therapy. However, the therapy showed positive effects on abdominal aorta wall thickness and parameters of oxidative stress (malondialdehyde - MDA, proxidative-antioxidative balance - PAB) and anti- oxidative protection (reduced glutathione - GSH, paraoxanase 1 - PON1, superoxide dismutase - SODA SH groups), especially ALTINC was successful in oxidative status improvement. Conclusion. Separate treatments comparison showed that artichoke leaf tincture is very potent antioxidant with beneficial effects in early stages of atherosclerosis. Since atorvastatin and constituents of ALTINC probably have different mechanisms of action, simultaneous use of both therapies could be beneficial but should be further investigated since our results showed that ALTINC is less effective when used in combination with atorvastatin., Uvod/Cilj. Savremena istraživanja sve više se okreću mogućnosti kombinovanja konvencionalne terapije sa biljnim lekovitim proizvodima. Cilj ovog istraživanja bio je praćenje efekata atorvastatina (CAS broj 134523-00-5), poznatog leka koji se koristi u terapiji hiperlipidemije, i tinkture lista artičoke primenjenih pojedinačno, kao i u obliku kombinovane terapije. Metode. Eksperimentalne životinje bile su podeljene u pet grupa: grupa I bila je kontrolna i činili su je pacovi hranjeni standardnom hranom za glodare tokom 11 nedelja, dok su preostale četiri grupe (II-V) činili pacovi koji su hranjeni standardnom hranom tokom prve nedelje, a potom u narednih 10 hranom bogatom holesterolom. Grupa II nije dobijala nikakav tretman, dok su III, IV i V posle 4. nedelje od početka uzimanja hrane bogate holesterolom, tokom narednih šest nedelja tretirane per os, redom: atorvastatinom u dozi od 1,15 mg/kg, tinkturom artičoke u dozi od 0,1 mL/kg i njihovom kombinacijom u istim dozama. Rezultati. Hrana bogata holesterolom izazvala je uznapredovalu hiperholesterolemiju na koju terapija nije značajno delovala. Terapija je pokazala povoljan efekat na debljinu zida trbušne aorte, parametre oksidativnog stresa (malondialdehid - MDA, prooksidativni-antioksidativni balans - PAB) i anti-oksidativne zaštite (redukovani glutation - GSH, SH grupe, paraoksonazu1 - PON1, superoksid dismutazu - SOD). Tinktura lista artičoke pokazala se najboljom u poboljšanju oksidativnog statusa. Zaključak. Poređenje pojedinačne terapije pokazalo je da tinktura lista artičoke ima jako anti-oksidativno dejstvo i pokazuje povoljne efekte u početnim fazama aterosklerotskog procesa. S obzirom na to da atorvastatin i komponente tinkture lista artičoke verovatno deluju različitim mehanizmima, kombinovana primena može imati povoljne efekte, ali se mora dodatno ispitati jer dobijeni rezultati ukazuju da je tinktura lista artičoke manje efikasan kada se primenjuje zajedno sa atorvastatinom.

Atorvastatin pripada grupi antihiperlipidemijskih lekova poznatih pod nazivom statini.Osnovni mehanizam delovanja ovih lekova je specifična, kompetitivna i reverzibilnainhibicija HMG-CoA reduktaze, enzima koji je značajan za proces biosinteze holesterola.Osim direktnog dejstva na biosintezu holesterola, atorvastatin pokazuje niz plejotropnihefekata koji imaju povoljno dejstvo na aterosklerotske promene. Atorvastatin metaboliše ujetri pod dejstvom CYP3A4 enzima pri čemu nastaju dva aktivna metabolita: ortohidroksiatorvastatini para-hidroksiatorvastatin i tri neaktivna metabolita: atorvastatin-lakton,orto-hidroksiatorvastatin-lakton i para-hidroksiatorvastatin-lakton.Artičoka (Cynara scolymus L., Asteraceae) je zeljasta, jednogodišnja biljkarasprostranjena širom Mediterana. Terapija hiperlipidemija, pored lekova uključuje inefarmakološke mere (promena ishrane, fizičke vežbe, prestanak pušenja i unošenja alkohola,primena biljnih ekstrakata). Obzirom da su svi delovi artičoke bogati jedinjenjima koja seponašaju kao prirodni antioksidansi, ekstrakt lista artičoke i atorvastatin se često u terapijiprimenjuju zajedno.Cilj doktorske disertacije je da se ispita uticaj vodeno-etanolnog ekstrakta lista artičoke(Tinctura Cynarae) na metabolizam atorvastatina i opravdanost istovremene primeneatorvastatina i navedenog biljnog ekstrakta. Za ispitivanja su korišćene komercijalne biljnekapi na bazi artičoke u kojima je kvantifikovan sadržaj cinarina i hlorogenske kiselineprimenom HPLC metode (određen sadržaj obe komponente je 0,2 %).Eksperimentalni rad je zasnovan na određivanju i praćenju promene koncentracijemetabolita atorvastatina: orto-hidroksiatorvastatina, para-hidroksiatorvastatina i atorvastatinlaktonau uzorcima plazme eksperimentalnih životinja koje su bile na aterogenoj ishrani i kojesu primale atorvastatin kao monoterapiju ili zajedno sa ekstraktom lista artičoke. Za izvođenjeeksperimenta korišćeni su pacovi soja Wistar. Životinje su podeljene u 5 grupa koje su bile nara, Atorvastatin belongs to the group of antihyperlipidemic drugs known as statins. Thebasic mechanism of action of these drugs is specific, competitive and reversible inhibition ofHMG-CoA reductase, an enzyme involved in cholesterol biosynthesis. In addition,atorvastatin shows many beneficial pleiotropic effects. Atorvastatin is metabolized in the liverunder the influence of the CYP3A4 enzyme to two active metabolites: orthohydroxyatorvastatinand para-hydroxyatorvastatin and three inactive metabolites: orthohydroxyatorvastatinlactone, para-hydroxyatorvastatin lactone and atorvastatin lactone.Artichoke (Cynara scolymus L., Asteraceae) is annual plant, distributed throughoutMediterranean. The treatment of hyperlipidemia, in addition to pharmacotherapy, includesnonpharmacological measures (diet changes, physical activity, cessation of smoking andalcohol intake, use of herbal extracts). Since all the parts of artichoke plant are rich in naturalantioxidants, artichoke leaf extract and atorvastatin are often used together.The Ph. D. disertation is focused to investigate the effect of aqueous-ethanolic extractof artichoke (Tinctura Cynarae) on the metabolism of atorvastatin and justification of coadministrationof atorvastatin and herbal extract mentioned above. Experiments wereconducted using commercial artichoke preparation. The contents of chlorogenic acid andcynarin in Tinctura Cynarae were quantified by means of the HPLC method (determinedcontent of both components is 0.2 %).Experimental work is based on determination and monitoring changes in theconcentration of atorvastatin metabolites: ortho-hydroxyatorvastatin, parahydroxyatorvastatinand atorvastatin lactone in the plasma samples of experimental animalsfed with atherogenic diet and treated with atorvastatin (alone or in combination with artichokeleaf extract). Experiments were conducted on experimental animals (Wistar rats). The animalswere divided into 5 groups on different diet and/or therapy. One group of animals w

Lipophilicity parameters (logP) were determined for thirteen synthesized β-hydroxy-β-arilalkanoic acids using reversed phase high performance liquid chromatography. Anti-inflammatory activity and potential selectivity towards cyclooxygenase-2 inhibition of synthetized compounds was assessed. Stationary phase was octadecyl modified (C-18) silicagel, and four used mobile phases contained different amount of methanol. Both synthetized and standard compounds with known logP values (aspirin, ibuprofen, ketoprofen, naproxen and phenanthrene) were tested in a chromatographic system. Using retention times for each standard and synthesized compound logk values (logarithm of capacity factor) were calculated. Intercept on a graph showing dependency of logk from methanol amount in the mobile phase for each compound represents logKw(capacity factor when organic solvent amount is zero). Graph showing linear dependency of logP of standard compounds from experimentally obtained logKw values was plotted. LogP values for synthetized compounds were obtained by interpolation from the plotted graph. Obtained values are in a range from 2.901 to 3.847. The best correlation between experimentally obtained and predicted logP values was using KOWWIN software (R2=0.8864), which makes this software appropriate for predicting logP values of this type of compounds., Parametri lipofilnosti (logP) su određeni za trinaest sintetisanih β-hidroksi-β-arilalkanskih kiselina primenom reverzno fazne tečne hromatografije. Ispitivanje je urađeno na derivatima kojima je tokom prethodnih istraživanja okarakterisana antiinflamatorna aktivnost i pretpostavljena je potencijalna selektivnost prema inhibiciji ciklooksigenaze-2. Oktadecil-modifikovani (C-18) silikagel je predstavljao stacionarnu fazu, a korišćene su četiri mobilne faze u kojima je variran udeo metanola. Hromatografski su testirana jedinjenja sa poznatim logP vrednostima (aspirin, ibuprofen, ketoprofen, naproksen i fenantren) i sintetisana jedinjenja. Na osnovu retencionog vremena za svako standardno i sintetisano jedinjenje izračunate su vrednosti logk (logaritam faktora kapaciteta). Odsečak na y osi grafika zavisnosti logk od udela metanola u mobilnoj fazi za svako jedinjenje predstavlja vrednost logKw (vrednost retencionog faktora za hromatografski sistem u kome je sadržaj organske komponente nula) za dato jedinjenje. Konstruisan je grafik zavisnosti logP za standardna jedinjenja od njihovih eksperimentalno dobijenih logKw vrednosti i uspostavljena je linearna zavisnost. Interpolacijom logKw sa grafika su očitane vrednosti logP za sintetisana jedinjenja. Dobijene vrednosti su u opsegu od 2,901 do 3,847. Za predviđanje logP vrednosti korišćeni su računarski programi: AlogPS, Molinspiration, MarvinSketch i KOWWIN. Najbolja korelacija između eksperimentalno određenih i predviđenih rezultata je u programu KOWWIN (R2=0,8864), što čini ovaj program pogodnim za predviđanje logP vrednosti ovog tipa jedinjenja.

Composite coating of antibiotic gentamicin (Gent), natural polymer chitosan (CS), and hydroxyapatite (HAP) was successfully assessed by applying the electrophoretic deposition (EPD) technique. EPD was performed under optimized deposition conditions (5 V, 12 min) on pure titanium plates, to obtain HAP/CS and HAP/CS/Gent composite coatings in a single step from three-component aqueous suspension, with favorable antibacterial properties. Composite coatings were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray photoelectron analysis, confirming the formation of composite HAP/CS and HAP/CS/Gent coatings on the titanium surface, which is due to intermolecular hydrogen bonds. Employing the XRD technique, HAP was detected by obtaining the characteristic diffraction maximums. Good antibacterial activity of the composite coating loaded with antibiotic (HAP/CS/Gent) was confirmed against Staphylococcus aureus and Escherichia coli, pointing to the high potential for bioapplication. Introduction of gentamicin in HAP/CS/Gent coating caused very mild cytotoxicity in the tested cell lines MRC-5 and L929. MTT testing was used to evaluate cell viability, and HAP/CS was classified as noncytotoxic.

Paraoxonases isoenzymes, PON1, PON2 and PON3, have important antioxidative and anti-inflammatory properties in blood and cells. They prevent oxidation of low and high density lipoprotein particles, foam cells formation and development of atherosclerosis. The authors investigated effects of high fat diet and atorvastatin therapy on paraoxonases gene expression levels and distribution in different rat organs. Liver, white adipose tissue (WAT) and aorta were taken from young male Wistar rats that were fed with normal diet (ND), atherogenic diet (AD) and atherogenic diet with 1.14 mg of atorvastatin per kg (ADA). Messenger RNA (mRNA) relative levels of paraoxonase 1 (PON1), paraoxonase 2 (PON2) and paraoxonase 3 (PON3) were measured in rat organs using real-time polymerase chain reaction (PCR). PON1 mRNA expression levels were down-regulated in ADA compared to AD group. ND group had significantly lower PON2 mRNA expression than AD group. PON1 mRNA expression levels were higher in liver than in aorta in group of rats on ND, AD and ADA. PON2 mRNA expression was higher in WAT than in aorta only in ADA group of rats. PON2 and PON3 were significantly higher than PON1 in aorta of rats on each ND, AD or ADA.

Context: Polyphenols and flavonoids in artichoke leaf tincture (ALT) protect cells against oxidative damage. Objectives: We examined ALT effects on deoxyribonucleic acid (DNA) damage and lipid profiles in rat plasma and gene expression in rat aorta [haemeoxygenase-1 (HO1), haemeoxygenase-2 (HO2), NADPH oxidase 4 (NOX-4), monocyte chemoattractant protein-1 (MCP-1) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2)]. Materials and methods: Eighteen male Wistar albino rats were divided into three groups (n=6/group): The control group (CG) was fed with standard pellet chow for 11 weeks; the AD group was fed for a similar period of time with pellet chow supplemented with 2% cholesterol, 3% sunflower oil and 1% sodium cholate. The ADA group was fed with pellet chow (for 1 week), the atherogenic diet (see above) for the following 4 weeks and then with ALT (0.1 mL/kg body weight) and atherogenic diet for 6 weeks. According to HPLC analysis, the isolated main compounds in ALT were chlorogenic acid, caffeic acid, isoquercitrin and rutin. Results: Normalized HO-1 [0.11 (0.04-0.24)] and MCP-1 [0.29 (0.21-0.47)] mRNA levels and DNA scores [12.50 (4.50-36.50)] were significantly lower in the ADA group than in the AD group [0.84 (0.35-2.51)], p = 0.021 for HO-1 [0.85 (0.61-3.45)], p = 0.047 for MCP-1 and [176.5 (66.50-221.25)], p = 0.020 for DNA scores. HO-1 mRNA was lower in the ADA group than in the CG group [0.30 (0.21-0.71), p = 0.049]. Conclusions: Supplementation with ALT limited the effects of the atherogenic diet through reduced MCP-1 expression, thereby preventing oxidative damage.

The aim of the present study was to optimize a chromatographic method for the analysis of atorvastatin (acid and lactone forms), ortho- and para-hydroxyatorvastatin by using an experimental design approach. Optimization experiments were conducted through a process of screening and optimization. The purpose of a screening design is to identify the factors that have significant effects on the selected chromatographic responses, and for this purpose a full 23 factorial design was used. The location of the true optimum was established by applying Derringer's desirability function, which provides simultaneously optimization of all seven responses. The ranges of the independent variables used for the optimization were content of acetonitrile in mobile phase (60-70%), temperature of column (30-40 C degrees) and flow rate (0.8-1.2 mL min(-1)). The influences of these independent variables were evaluated for the output responses: retention time of first peak (p-hydroxyatorvastatin) and of last peak (atorvastatin, lactone form), symmetries of all four peaks and relative retention time of p-hydroxyatorvastatin. The primary goal of this investigation was establishing a new simple and sensitive method that could be used in analysis of biological samples. The method was validated and successfully applied for determination of atorvastatin (acid and lactone forms) and its metabolites in plasma.

The aim of this study was to investigate the encapsulation of a-lipoic acid (LA) onto chitosan microbeads in order to achieve a sustained release. Microbeads of different compositions were synthetized by inverse emulsion method, and characterized by in vitro swelling and drug release studies, FT-IR, DSC and SEM analyses. The encapsulation of LA was performed by swelling of previously synthetized dry microbeads in LA solution. The encapsulation efficiency was determined in terms of LA concentration, using liquid chromatography tandem mass spectrometry (LC-MS/MS). The swelling of synthetized microbeads was well pronounced in the acidic media. FT-IR analysis confirmed the presence of LA in microbeads and its interactions with matrices, which was in agreement with the results revealed by DSC analysis. SEM analysis revealed the porous structure, micron-size and spherical shape of the synthetized beads. Encapsulation efficiency was in the range from 46.8 to 58.5% depending on the hydrogel composition. The microbeads exhibited sustained release of LA under conditions mimicking gastrointestinal tract. Results of antioxidant activity of released LA showed good correlation with the concentration of the released LA. The obtained results suggested that synthetized microbeads have promising potential for oral administration with reduced dosing frequency in comparison to the immediate release formulations.

Atorvastatin pripada grupi antihiperlipidemijskih lekova poznatih pod nazivom statini. Osnovni mehanizam delovanja ovih lekova je specifična, kompetitivna i reverzibilna inhibicija HMG-CoA reduktaze, enzima koji je značajan za proces biosinteze holesterola. Osim direktnog dejstva na biosintezu holesterola, atorvastatin pokazuje niz plejotropnih efekata koji imaju povoljno dejstvo na aterosklerotske promene. Atorvastatin metaboliše u jetri pod dejstvom CYP3A4 enzima pri čemu nastaju dva aktivna metabolita: ortohidroksiatorvastatin i para-hidroksiatorvastatin i tri neaktivna metabolita: atorvastatin-lakton, orto-hidroksiatorvastatin-lakton i para-hidroksiatorvastatin-lakton. Artičoka (Cynara scolymus L., Asteraceae) je zeljasta, jednogodišnja biljka rasprostranjena širom Mediterana. Terapija hiperlipidemija, pored lekova uključuje i nefarmakološke mere (promena ishrane, fizičke vežbe, prestanak pušenja i unošenja alkohola, primena biljnih ekstrakata). Obzirom da su svi delovi artičoke bogati jedinjenjima koja se ponašaju kao prirodni antioksidansi, ekstrakt lista artičoke i atorvastatin se često u terapiji primenjuju zajedno. Cilj doktorske disertacije je da se ispita uticaj vodeno-etanolnog ekstrakta lista artičoke (Tinctura Cynarae) na metabolizam atorvastatina i opravdanost istovremene primene atorvastatina i navedenog biljnog ekstrakta. Za ispitivanja su korišćene komercijalne biljne kapi na bazi artičoke u kojima je kvantifikovan sadržaj cinarina i hlorogenske kiseline primenom HPLC metode (određen sadržaj obe komponente je 0,2 %). Eksperimentalni rad je zasnovan na određivanju i praćenju promene koncentracije metabolita atorvastatina: orto-hidroksiatorvastatina, para-hidroksiatorvastatina i atorvastatinlaktona u uzorcima plazme eksperimentalnih životinja koje su bile na aterogenoj ishrani i koje su primale atorvastatin kao monoterapiju ili zajedno sa ekstraktom lista artičoke. Za izvođenje eksperimenta korišćeni su pacovi soja Wistar. Životinje su podeljene u 5, Atorvastatin belongs to the group of antihyperlipidemic drugs known as statins. The basic mechanism of action of these drugs is specific, competitive and reversible inhibition of HMG-CoA reductase, an enzyme involved in cholesterol biosynthesis. In addition, atorvastatin shows many beneficial pleiotropic effects. Atorvastatin is metabolized in the liver under the influence of the CYP3A4 enzyme to two active metabolites: orthohydroxyatorvastatin and para-hydroxyatorvastatin and three inactive metabolites: orthohydroxyatorvastatin lactone, para-hydroxyatorvastatin lactone and atorvastatin lactone. Artichoke (Cynara scolymus L., Asteraceae) is annual plant, distributed throughout Mediterranean. The treatment of hyperlipidemia, in addition to pharmacotherapy, includes nonpharmacological measures (diet changes, physical activity, cessation of smoking and alcohol intake, use of herbal extracts). Since all the parts of artichoke plant are rich in natural antioxidants, artichoke leaf extract and atorvastatin are often used together. The Ph. D. disertation is focused to investigate the effect of aqueous-ethanolic extract of artichoke (Tinctura Cynarae) on the metabolism of atorvastatin and justification of coadministration of atorvastatin and herbal extract mentioned above. Experiments were conducted using commercial artichoke preparation. The contents of chlorogenic acid and cynarin in Tinctura Cynarae were quantified by means of the HPLC method (determined content of both components is 0.2 %). Experimental work is based on determination and monitoring changes in the concentration of atorvastatin metabolites: ortho-hydroxyatorvastatin, parahydroxyatorvastatin and atorvastatin lactone in the plasma samples of experimental animals fed with atherogenic diet and treated with atorvastatin (alone or in combination with artichoke leaf extract). Experiments were conducted on experimental animals (Wistar rats). The animals were divided into 5 groups on different diet and/or therapy.

In this paper, influence of temperature and light on stability of montelukast in solutions (standard substance, chewable tablets and film coated tablets) which were prepared during routine analysis of related substances was investigated. The content of montelukast and degradation products was determined by HPLC method at defined time intervals (influence of temperature was tested at the beginning, after 24 hours, and after 48 hours, and influence of light was tested at the beginning of the experiment and after 12 hours). Stability of montelukast in tested solutions under influence of temperature was acceptable. The content of montelukast ranged from 98 % to100 %, which meets the pharmacopoeia requirements and specifications. Individual and total impurities were within acceptable limits. Presence of photosensitive functional groups in structure of montelukast led to significant photodegradation. Individual and total impurities in samples which were under influence of light were above acceptable limits. Photodegradation occured during first 12 hours. Content of MOK-3 sulphoxide and unknown impurity on RRT 0.76 was above limits in all examined samples. Over a period of 12 h the content of those impurities grew 8-40 fold compared to time zero values., U radu je dat prikaz ispitivanja uticaja temperature i svetlosti na stabilnost montelukasta u rastvorima (standardne supstance, tabletama za žvakanje i filmom obloženih tableta) koji se pripremaju u rutinskoj analizi u toku postupka ispitivanja prisustva srodnih supstanci. Sadržaj montelukasta i nastalih degradacionih proizvoda praćen je primenom RP-HPLC metode u definisanim vremenskim intervalima (0, 24 i 48h kada je u pitanju temperatura, odnosno 0 i 12h kada je u pitanju svetlost). Rezultati ispitivanja uticaja temperature, kao spoljašnjeg faktora nestabilnosti, ukazuju da su analizirani rastvori standarda montelukasta, tableta za žvakanje i filmom obloženih tableta stabilni u prihvatljivim granicama. Sadržaj montelukasta se kreće od 98 % - 100 % što zadovoljava farmakopejske zahteve, kao i zahteve specifikacije proizvoda. Pojedinačne i ukupne nečistoće su u dozvoljenim granicama. Prisustvo fotoreaktivnih funkcionalnih grupa u strukturi montelukasta uslovilo je nastanak fotodegradacionih proizvoda u količinama koje su izvan granica definisanih u monografiji montelukasta, kao i granica definisanih u specifikaciji gotovog proizvoda. Do fotodegradacije dolazi već u toku prvih 12 h. Porast sadržaja MOK-3 sulfoksida i nečistoće sa relativnim retencionim vremenom oko 0,76 zabeležen je u sva tri ispitivana uzorka. U vremenskom intervalu od 12 h uočen je porast sadržaja navedenih nečistoća 8-40 puta u poređenju sa vrednostima u početnom vremenu ispitivanja.