[Factors associated with success of a smoking cessation program].

Background: Smoking cessation therapies include counseling, psychological management and pharmacological therapy. Varenicline is the most effective and safe medication available.

Aim: To study risk factors for the failure of pharmacological smoking cessation therapy with varenicline.

[Results of a multidisciplinary program to quit smoking].

Background: Therapies to quit smoking are based on counseling, psychological therapy (PT), nicotine replacement therapy, bupropion or varenidine.

Aim: To report the results of a multidisciplinary program to quit smoking.

Material And Methods: Patients aged l8 years or more, motivated to quit smoking were admitted in a program based in counseling and PT, with or without pharmacological therapy.

Solubility behavior and prediction for antihelmintics at several temperatures in aqueous and nonaqueous mixtures.

A model based on solubility parameters is proposed to predict the solubility curves of antihelmintic drugs at several temperatures, including aqueous and non-aqueous mixtures. The solubility of the drugs was measured in ethanol-water and ethanol-ethyl acetate mixtures at 15-35 degrees C (mebendazole) and at 25 degrees C (thiabendazole and metronidazole). The solid phases were analyzed by differential scanning calorimerty.

Influence of temperature on the solubilization of thiabendazole by combined action of solid dispersions and co-solvents.

Co-solvents and solid dispersions with polyvinyl pyrrolidone were tested to increase solubility of thiabendazole. Solid dispersions were prepared by the solvent method and analyzed by differential scanning calorimetry. The solubility was measured at 15-35 degrees C in aqueous (ethanol-water) and non-aqueous (ethanol-ethyl acetate) mixtures.

Relationship between swelling of hydroxypropylmethylcellulose and the Hansen and Karger partial solubility parameters.

A model that relates the equilibrium swelling of hydroxypropylmethylcellulose to the partial solubility parameters of both the polymer and the solvents is proposed to interpret and correlate the experimental data. The non-specific interactions are expressed as the dispersion delta(d) and polar delta(p) solubility parameters of Hansen, or as a combination of both. Hydrogen bonding is represented by the acidic delta(a) and the basic delta(b) Karger solubility parameters.

A new method to determine the partial solubility parameters of polymers from intrinsic viscosity.

A modification of the extended Hansen method, formerly used to determine the partial solubility parameters of drugs and non-polymeric excipients is tested with a polymer for the first time. The proposed method relates the logarithm of the intrinsic viscosities of the polymer in a series of solvents and solvent mixtures with the Hansen (three parameter model) and Karger (four parameter model) partial solubility parameters. The viscosity of diluted solutions of hydroxypropyl methylcellulose (HPMC) was determined in pure solvents and binary mixtures of varying polarity.

Solubility and phase separation of benzocaine and salicylic acid in 1,4-dioxane-water mixtures at several temperatures.

The solubilities of benzocaine and salicylic acid were determined in water-dioxane mixtures at several temperatures (5-40 degrees C for benzocaine and 10-40 degrees C for salicylic acid). The solubility curves as a function of dioxane ratio showed a maximum at 90% dioxane at all temperatures. Above 25 degrees C, the homogeneous mixture splits into two liquid immiscible phases.

Deviation from linearity of drug solubility in ethanol/water mixtures.

A new empirical function that describes the deviation from linearity of solubility of a drug in an ethanol/water matrix is applied to the experimental data for 51 compounds. The proposed model is a more accurate predictor of the co-solvent solubility profile than a general third order polynomial with the same number of parameters. Both the root mean square error and average absolute error for the proposed model are significantly lower than those of existing models.

Influence of solvent composition on the solid phase at equilibrium with saturated solutions of quinolones in different solvent mixtures.

The dissolution profiles and solubilities of three quinolonic drugs (oxolinic, pipemidic, and nalidixic acids) in different solvent mixtures were studied. The behavior of the solid phase, during solubility experiments was in-depth investigated with the aim of detecting possible crystalline modifications, such as polymorphic transitions or solvate formations, that might modify drug stability and/or solubility properties. In order to test the influence of both the nature and polarity of the co-solvents, aqueous and non-aqueous binary mixtures have been prepared by using Lewis base (dioxane and ethyl acetate) and amphiprotic co-solvents (ethanol and water).

A cosolvency model to predict solubility of drugs at several temperatures from a limited number of solubility measurements.

A cosolvency model to predict the solubility of drugs at several temperatures was derived from the excess free energy model of Williams and Amidon. The solubility of oxolinic acid, an antibacterial drug, was measured in aqueous (water+ethanol) and non-aqueous (ethanol+ethyl acetate) mixtures at several temperatures (20, 30, 35, 40 degrees C). Oxolinic acid displays a solubility maximum in each solvent mixture at solubility parameter values of 32 and 22 MPa(1/2).

Thermodynamic origin of the solubility profile of drugs showing one or two maxima against the polarity of aqueous and nonaqueous mixtures: niflumic acid and caffeine.

The purpose of this work was to investigate the origin of the different solubility profiles of drugs against the polarity of solvent mixtures with a common cosolvent. Niflumic acid and caffeine where chosen as model drugs. The solubilities were measured at five or six temperatures in aqueous (ethanol-water) and nonaqueous (ethyl acetate-ethanol) mixtures.