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Piera Di Martino - One of the best experts on this subject based on the ideXlab platform.

  • Preformulation study of nicergoline solid dispersions
    2014
    Co-Authors: Roberta Censi, Valentina Martena, Ela Hoti, Ledjan Malaj, Piera Di Martino
    Abstract:

    Nicergoline, a semisynthetic Ergot Derivative, which, in its crystalline state, is insoluble in water, was dispersed in polyvinylpyrrolidone K30 (PVP K30) to improve drug particle dissolution. Preformulation studies were carried out initially by Differential Scanning Calorimetry (DSC) and X-ray Powder Diffraction (XRPD) in order to predict the conditions and the possibility to actually obtain solid dispersions by mixing the two components at different proportions. Solid dispersions were finally prepared by dissolving nicergoline and PVP K30 in chloroform that was next evaporated under reduced pressure. Under these conditions, an amorphous powder was recovered in every proportion of the two components. Nicergoline demonstrated to be physically and chemically stable for one year. The dissolution studies revealed a very high dissolution rate of nicergoline from solid dispersions only lower than the pure amorphous form. This is the consequence of the molecular dispersion of nicergoline in the polymer that enhances the rate of drug release from the polymer

  • Preformulation study of nicergoline solid dispersions
    Journal of Thermal Analysis and Calorimetry, 2013
    Co-Authors: Roberta Censi, Valentina Martena, Ela Hoti, Ledjan Malaj, Piera Di Martino
    Abstract:

    Nicergoline, a semisynthetic Ergot Derivative, which, in its crystalline state, is insoluble in water, was dispersed in polyvinylpyrrolidone K30 (PVP K30) to improve drug particle dissolution. Preformulation studies were carried out initially by differential scanning calorimetry and X-ray powder diffraction in order to predict the conditions and the possibility to actually obtain solid dispersions by mixing the two components at different proportions. Solid dispersions were finally prepared by dissolving nicergoline and PVP K30 in chloroform that was next evaporated under reduced pressure. Under these conditions, an amorphous powder was recovered in every proportion of the two components. Nicergoline demonstrated to be physically and chemically stable for 1 year. The dissolution studies revealed a very high dissolution rate of nicergoline from solid dispersions only lower than the pure amorphous form. This is the consequence of the molecular dispersion of nicergoline in the polymer that enhances the rate of drug release from the polymer.

Fernando Gutierrez - One of the best experts on this subject based on the ideXlab platform.

Roberta Censi - One of the best experts on this subject based on the ideXlab platform.

  • Preformulation study of nicergoline solid dispersions
    2014
    Co-Authors: Roberta Censi, Valentina Martena, Ela Hoti, Ledjan Malaj, Piera Di Martino
    Abstract:

    Nicergoline, a semisynthetic Ergot Derivative, which, in its crystalline state, is insoluble in water, was dispersed in polyvinylpyrrolidone K30 (PVP K30) to improve drug particle dissolution. Preformulation studies were carried out initially by Differential Scanning Calorimetry (DSC) and X-ray Powder Diffraction (XRPD) in order to predict the conditions and the possibility to actually obtain solid dispersions by mixing the two components at different proportions. Solid dispersions were finally prepared by dissolving nicergoline and PVP K30 in chloroform that was next evaporated under reduced pressure. Under these conditions, an amorphous powder was recovered in every proportion of the two components. Nicergoline demonstrated to be physically and chemically stable for one year. The dissolution studies revealed a very high dissolution rate of nicergoline from solid dispersions only lower than the pure amorphous form. This is the consequence of the molecular dispersion of nicergoline in the polymer that enhances the rate of drug release from the polymer

  • Preformulation study of nicergoline solid dispersions
    Journal of Thermal Analysis and Calorimetry, 2013
    Co-Authors: Roberta Censi, Valentina Martena, Ela Hoti, Ledjan Malaj, Piera Di Martino
    Abstract:

    Nicergoline, a semisynthetic Ergot Derivative, which, in its crystalline state, is insoluble in water, was dispersed in polyvinylpyrrolidone K30 (PVP K30) to improve drug particle dissolution. Preformulation studies were carried out initially by differential scanning calorimetry and X-ray powder diffraction in order to predict the conditions and the possibility to actually obtain solid dispersions by mixing the two components at different proportions. Solid dispersions were finally prepared by dissolving nicergoline and PVP K30 in chloroform that was next evaporated under reduced pressure. Under these conditions, an amorphous powder was recovered in every proportion of the two components. Nicergoline demonstrated to be physically and chemically stable for 1 year. The dissolution studies revealed a very high dissolution rate of nicergoline from solid dispersions only lower than the pure amorphous form. This is the consequence of the molecular dispersion of nicergoline in the polymer that enhances the rate of drug release from the polymer.

  • Characterization of nicergoline polymorphs crystallized in several organic solvents.
    2011
    Co-Authors: Ledjan Malaj, Roberta Censi, D. Capsoni, L. Pellegrino, M. Bini, S. Ferrari, R. Gobetto, V. Massarotti, P. Di Martino
    Abstract:

    Nicergoline (NIC), a poorly water-soluble semisynthetic Ergot Derivative, was crystallized from several organic solvents, obtaining two different polymorphic forms, the triclinic form I and the orthorhombic form II. NIC samples were then characterized by several techniques such as (13)C cross-polarization magic angle spinning solid-state spectroscopy, room-temperature and high-temperature X-ray powder diffraction, differential scanning calorimetry, and by analysis of weight loss, solvent content, powder density, morphology, and particle size. Solubility and intrinsic dissolution rates determined for the two polymorphic forms in water and hydrochloride solutions (HCl 0.1 N) were always higher for form II than for form I, which is actually the form used for the industrial preparation of NIC medicinal products. Preformulation studies might encourage industry for the evaluation of polymorph II, as it is more suitable for pharmaceutical applications. Results in drug delivery, as well as those obtained by the above-mentioned techniques, and the application of Burger-Ramberger's rules make it possible to conclude that there is a thermodynamic relation of monotropy between the two polymorphs. This last assumption may help formulators in predicting the relative stability of the two form

Felix Javier Jimenezjimenez - One of the best experts on this subject based on the ideXlab platform.

Agostino Baruzzi - One of the best experts on this subject based on the ideXlab platform.

  • Pharmacokinetic Optimisation of Dopamine Receptor Agonist Therapy for Parkinson’s Disease
    CNS Drugs, 2000
    Co-Authors: Manuela Contin, Fiorenzo Albani, Roberto Riva, Agostino Baruzzi
    Abstract:

    Dopamine receptor agonists were originally developed as adjunctive therapies to ‘smooth out’ motor response fluctuations to levodopa in patients with advanced Parkinson’s disease. However, they are now used in the early stages of the disease, in monotherapy or combination with low doses of levodopa, to delay the onset of levodopa therapy and its complications. Oral dopamine agonists currently available worldwide for Parkinson’s disease include the older Ergot Derivatives bromocriptine and pergolide and the second generation non-ergoline compounds ropinirole and pramipexole. Other dopamine agonists that are used less frequently include cabergoline (a new ergoline drug, only recently released in some European countries as an antiparkinsonian drug), lisuride (an Ergot Derivative) and piribedil (an older non-Ergot compound). Data on the pharmacokinetics of oral dopamine agonists, especially the older Ergot Derivatives, are scarce and mostly refer to small groups of healthy young individuals. All these agents, with the exception of pramipexole, are subject to extensive enterohepatic first-pass metabolism. Their bioavailability is low and shows high intra- and interindividual variability. The pharmacodynamic properties of dopamine agonists relevant to their antiparkinsonian effect have not been clearly defined. As a result, an optimal dosage schedule for the treatment of Parkinson’s disease is generally identified using highly individualised empirical assessment. This involves considerable time expenditure and creates difficulty for patients, who have to follow complex titration schedules. Dopamine agonists appear to have a low potential for pharmacokinetic interaction with levodopa. Few data have been reported on the effect of coadministration on the pharmacodynamics of levodopa. The available data indicate that pergolide and bromocriptine significantly increase the duration of the motor response to levodopa, while baseline motor effects and the magnitude of motor response are substantially unchanged. Cabergoline also significantly prolongs the motor response to a dose of levodopa in patients experiencing motor fluctuations, but baseline motor scores are also significantly improved, suggesting a long-lasting effect. Subcutaneous apomorphine is currently the only non-oral formulation of a dopamine agonist available; it is used as add-on rescue therapy for patients who have advanced Parkinson’s disease and a wide spectrum of complex motor, sensory, autonomic and cognitive ‘wearing-off ’ phenomena not controlled by optimal oral dopaminergic therapy. Attempts to deliver apomorphine and other soluble dopamine agonists by more practical non-oral routes, such as intranasally or transdermally, have so far been of limited clinical utility or are currently still under investigation.