1,237 research outputs found

    Progressive ataxia with oculo-palatal tremor and optic atrophy

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    The final publication is available at Springer via doi: 10.​1007/​s00415-013-7136-

    Patients' Perception of Quality of Pre-Operative Informed Consent in Athens, Greece: A Pilot Study

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    BACKGROUND: We sought to perform a study to record and evaluate patients' views of the way surgeons communicate informed consent (IC) in Greece. METHODOLOGY/PRINCIPAL FINDINGS: A prospective pilot study was carried out in Athens from 9/2007 to 4/2008. The study sample was extracted from patients, operated by eight different surgeons, who volunteered to fill in a post-surgery self-report questionnaire on IC. A composite delivered information index and a patient-physician relationship index were constructed for the purposes of the analysis. In total, 77 patients (42 males) volunteered to respond to the questionnaire. The delivered information index scores ranged from 3 to 10, the mean score was 8, and the standard deviation (SD) was 1.9. All patients were aware of their underlying diagnosis and reason for surgery. However, a considerable proportion of the respondents (14.3%) achieved a score below or equal to 5. The patient-physician relationship scores ranged from 0 to 20, the mean score was 16 and the standard deviation (SD) was 4.3. The better the patient-physician relationship, the more information was finally delivered to the patient from the physician (Spearman's rank-order correlation coefficient was 0.4 and p<0.001). Delivered information index was significantly higher among participants who comprehended the right to informed consent, compared to participants who did not (p<0.001), and among participants who were given information regarding other possible therapeutic options (p = 0.001). 43% of the respondents answered that less than 10 minutes were spent on the consent process, 58.4% of patients stated that they had not been informed about other possible therapeutic choices and 28.6% did not really comprehend their legal rights to IC. CONCLUSIONS: Despite the inherent limitations and the small sample size that do not permit to draw any firm conclusions, results indicate that a successful IC process may be associated with specific elements such as the patient-physician relationship, the time spent by the physician to inform the patient, a participant's comprehension of the right to IC and the provision of information regarding other possible therapeutic options

    Razvoj i vrednovanje plutajućih tableta norfloksacina s produljenim zadržavanjem u želucu

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    Floating matrix tablets of norfloxacin were developed to prolong gastric residence time, leading to an increase in drug bioavailability. Tablets were prepared by the wet granulation technique, using polymers such as hydroxy propyl methylcellulose (HPMCK4M, HPMCK100M) and xanthan gum. Tablets were evaluated for their physical characteristics viz., hardness, thickness, friability, and mass variation, drug content and floating properties. Further, tablets were studied for in vitro drug release characteristics for 9 hours. The tablets exhibited controlled and prolonged drug release profiles while floating over the dissolution medium. Non-Fickian diffusion was confirmed as the drug release mechanism from these tablets, indicating that water diffusion and the polymer rearrangement played an essential role in drug release. The best formulation (F4) was selected based on in vitro characteristics and was used in vivo radiographic studies by incorporating BaSO4. These studies revealed that the tablets remained in the stomach for 180 ± 30 min in fasting human volunteers and indicated that gastric retention time was increased by the floating principle, which was considered desirable for absorption window drugs.Razvijene su plutajuće tablete norfloksacina koje se produljeno zadržavaju u želucu i time povećavaju bioraspoloživost. Tablete su pripravljene metodom vlažne granulacije, koristeći hidroksipropil metilcelulozu (HPMCK4M, HPMCK100M) i ksantan gumu. Tabletama su određena fizikalna svojstva (čvrstoća, debljina, lomljivost i varijacija mase) te sadržaj ljekovite tvari i plutajuća svojstva. Nadalje, praćeno je oslobađanje ljekovite tvari in vitro tijekom 9 h. Uočeno je da je oslobađanje kontrolirano i produljeno te da tablete plutaju u ispitivanom mediju. Mehanizam oslobađanja nije slijedio Fickov zakon, što ukazuje da difuzija vode i promjene u strukturi polimera imaju bitnu ulogu u oslobađanju ljekovite tvari. Najbolja formulacija (F4) in vitro uporabljena je s dodatkom barijevog sulfata za radiografska ispitivanja in vivo. Ispitivanja na volonterima koji su apstinirali od hrane pokazala su da primjena plutajućih tableta produljuje vrijeme zadržavanja u želucu na 180 ± 30 min

    Izrada i karakterizacija IPN alginatnih i želatinskih mikrogelova s tramadolom: Optimiranje pomoću metode odzivnih površina

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    Tramadol-loaded interpenetrating polymer network (IPN) alginate-gelatin (AG) microgels (MG) were prepared by the chemical cross-linking technique with glutaraldehyde as cross-linking agent and were optimized using response surfaces. A central composite design for 2 factors, at 3 levels each, was employed to evaluate the effect of critical formulation variables, namely the amount of gelatin (X1) and glutaraldehyde (X2) on geometric mean diameter, encapsulation efficiency, diffusion coefficient (D), amount of mucin adsorbed per unit mass (Qe) and 50 % drug release time (t50). Microgels with average particle size in the range of 44.31102.41 m were obtained. Drug encapsulation up to 86.5 % was achieved. MGs were characterized by FT-IR spectroscopy to assess formation of the IPN structure and differential scanning calorimetry (DSC) was performed to understand the nature of drug dispersion after encapsulation into IPN microgels. Both equilibrium and dynamic swelling studies were performed in pH 7.4 phosphate buffer. Diffusion coefficients and exponents for water transport were determined using an empirical equation. The mucoadhesive properties of MGs were evaluated in aqueous solution by measuring the mucin adsorbed on MGs. Adsorption isotherms were constructed and fitted with Freundlich and Langmuir equations. In vitro release studies indicated the dependence of drug release on the extent of crosslinking and amount of gelatin used in preparing IPNs. The release rates were fitted to power law equation and Higuchi’s model to compute the various drug transport parameters, n value ranged from 0.4055 to 0.5754, suggesting that release may vary from Fickian to quasi-Fickian depending upon variation in the formulation composition.Interpenetrirajući umreženi polimerni (IPN) alginatno-želatinski (AG) mikrogelovi (MG) tramadola pripravljeni su metodom umrežavanja koristeći glutaraldehid kao sredstvo za umrežavanje. Pripravci su optimirani pomoću odzivnih površina. Kompozitini dizajn s dva faktora na tri nivoa upotrijebljen je za procjenu kritičnih formulacijskih varijabli: praćen je utjecaj količine želatine (X1) i glutaraldehida (X2) na prosječnu veličinu čestica, sposobnost kapsuliranja, koeficijent difuzije (D), količinu adsorbiranog mucina po jedinici mase (Qe) i vrijeme potrebno za oslobađanje 50 % lijeka (t50). Dobiveni su mikrogelovi prosječne veličine čestica od 44,31 do 102,41 m, a maksimalno postignuto vezanje lijeka bilo je 86,5 %. Mikrogelovi su karakterizirani FT-IR spektroskopijom i diferencijalnom pretražnom kalorimetrijom (DSC). Ravnotežne i dinamičke studije bubrenja provedene su u fosfatnom puferu pH 7,4. Koeficijenti difuzije i eksponenti za transport vode određeni su pomoću empirijske jednadžbe. Mukoadhezivna svojstva MGs evaluirana su u vodenoj otopini mjerenjem adsorpcije mucina na mikrogelove. Konstruirane su adsorpcijske izoterme i uspoređene s Freudlichovim i Langmuirovim jednadžbama. Pokusi in vitro pokazuju da oslobađanje ljekovite tvari ovisi o stupnju umreženja i količini želatine upotrijebljene u pripravi IPN. Vrijednosti oslobađanja uvrštene su u jednadžbu zakona potencije i u Higuchijev model kako bi se izračunali razni parametri prijenosa lijeka; n vrijednosti bile su između 0,4055 i 0,5754, što ukazuje na to da oslobađanje varira od Fickovog do kvazi-Fickovog, ovisno o sastavu pripravka

    Relaxational study of poly(vinylpyrrolidone-co-butyl acrylate) membrane by dielectric and dynamic mechanical spectroscopy

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    [EN] A poly(vinylpyrrolidone-co-butyl acrylate) (60VP-40BA) membrane is synthesized as a tractable and hydrophilic material, obtaining a water-swelling percentage around 60%. An investigation of molecular mobility by means of differential scanning calorimetry, dynamic mechanical analysis and broadband dielectric relaxation spectroscopy (DRS) is fulfilled in the dry membrane. Dielectric and viscoelastic relaxation measurements are carried out on the 60VP-40BA sample at several frequencies between -150 and 150 degrees C. The dielectric spectrum shows several relaxation processes labelled gamma, beta and alpha in increasing order of temperature, whereas in the mechanical spectrum only the beta and alpha relaxation processes are completely defined. In the dielectric measurements, conductive contributions overlap the alpha-relaxation. The apparent activation energies have similar values for the beta-relaxation in both, the mechanical and the dielectric measurements. The beta process is a Johari-Golstein secondary relaxation and it is related to the local motions of the pyrrolidone group accompanied by the motion of the segments of the polymer backbone. The gamma process is connected with the butyl unit's motions, both located in the side chains of the polymer.BRF, MC, PO and MJS are grateful to CICYT for grant MAT2012-33483. FG and JMG thank the Spanish Ministerio de Economia y Competitividad-FEDER (MAT2011-22544) and the Consejeria de Educacion-Junta de Castilla y Leon (BU001A10-2).Redondo Foj, MB.; Carsí Rosique, M.; Ortiz Serna, MP.; Sanchis Sánchez, MJ.; García, FC.; García. José Miguel (2013). Relaxational study of poly(vinylpyrrolidone-co-butyl acrylate) membrane by dielectric and dynamic mechanical spectroscopy. JOURNAL OF PHYSICS D-APPLIED PHYSICS. 46(29):295304-1-295304-12. https://doi.org/10.1088/0022-3727/46/29/295304S295304-1295304-12462

    Evaluation of sesamum gum as an excipient in matrix tablets

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    In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated
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