Oxaliplatin preformulation studies for the development of innovative topical drug delivery systems

Journal of Thermal Analysis and Calorimetry - The objectives of this study were to verify the viability of the photoinitiating system using curcumin as a photoinitiator and glycerol as a...     

Preformulation studies to guide the development of raloxifene lipid-based delivery systems

Journal of Thermal Analysis and Calorimetry - The composition and temperature dependence of viscosity and configuration entropy of glasses with chemical composition close to that used for CHROMPIC...     

Selection of excipients for the development of carvedilol loaded lipid-based drug delivery systems

Journal of Thermal Analysis and Calorimetry - Carvedilol (CARV) is a widely used drug, which has shown low oral bioavailability. Lipid-based drug delivery systems (LBDDS) appear as promising...     

Carvedilol: decomposition kinetics and compatibility with pharmaceutical excipients

Carvedilol (CARVE) is an important cardiovascular drug with limited bioavailability. To improve its therapeutic performance, the investigation of new dosage forms is of great interest due its relevance in clinical applications. Therefore, the aim of this work was to evaluate the stability of CARVE and its drug–excipient compatibility to support its pharmaceutical development. Kinetic analysis under isothermal conditions using thermogravimetry was performed to determine the activation energy of CARVE through an Arrhenius plot. Differential scanning calorimetry, Fourier transform infrared spectroscopy, and optical microscopy were used to test binary mixtures of CARVE and selected excipients. The activation energy of CARVE was 81.2 kJ mol^?1, and from the compatibility studies, all the excipients showed strong thermal interactions, presenting changes in the melting profile of the drug. In addition, analytical assays revealed no physical or chemical changes; because of this, all eight excipients studied are considered compatible and are recommended in formulations containing CARVE. All the evidence together attests to the low chemical reactivity of CARVE and provides useful information for the development of new pharmaceutical formulations containing CARVE.     

Thermal analysis used to guide the production of thymol and Lippia origanoides essential oil inclusion complexes with cyclodextrin

This study aimed to use thermal analysis and other analytical tools to guide the production of thymol (TML) and essential oil of Lippia origanoides (EO) solid inclusion complexes from a screening of different cyclodextrins (CDs) types and production methods (freeze drying, spray drying, rotary evaporation and supercritical CO₂). According to the phase solubility diagrams, the best complexation efficiency of TML was achieved using hydroxypropyl-β-cyclodextrin (~ 0.7), comparing to the natives CDs, which showed values below 0.5. Thermogravimetry was effective in evaluating the amount of drug inclusion complexes in each solid sample by measuring the evaporation of TML, which was dependent of its degree of interaction with the CD. Freeze drying was the most effective method in originating true inclusion complexes in solid state producing the encapsulation of nearly 70% of available TML which were stable at temperature ranges from 200 to 280 °C. Indeed, according to the stability assay, the shelf-life increase achieved for the TML standard was 354%, while the EO had a stability increase of around 45%. Finally, the antifungal effect against Candida albicans (ATCC 14053) was increased in complexed forms in about 1.5 times and 5.4 times for EO and TML, respectively, while the antifungal activity for Trichophyton mentagrophytes (ATCC 11481) was increased with TML and EO encapsulated with CD in more than 22 times and 45 times, respectively, compared to their free forms. Thus, the optimized inclusion complexes seem to be promising in pharmaceutical field for a future development of topical preparations containing TML and its natural substrates.

     

Evolution of quality on pharmaceutical design: regulatory requirement?

Accreditation and Quality Assurance - Quality by design (QbD) concept was first outlined by quality pioneer Joseph M. Juran, who believed quality could be designed into a product, preventing,...     

Polymorphic screen and drug–excipient compatibility studies of the antichagasic benznidazole

The purpose of this study was to investigate the polymorphism and compatibility of benznidazole (BNZ), a drug used in the treatment of Chagas disease. This drug was subjected to a polymorphic screen using a number of solvents and precipitation procedures to explore the possible existence of different crystal structures of BNZ. The compatibility of BNZ with selected pharmaceutical excipients was evaluated in binary mixtures, in a ratio of 1:1 (w/w). These results were then analyzed with a variety of techniques, including differential scanning calorimetry, Fourier transform infrared spectroscopy, and X-ray powder diffractometry. No polymorphic forms of BNZ were detected despite some observed changes in the DSC profile. The thermal data indicate interaction of the drug with excipients hydroxyethylcellulose, polyethylene glycol, and hydroxypropyl-β-cyclodextrin. Additional studies using infrared spectroscopy confirm the incompatibility of BNZ with only the polyethylene glycol. This excipient should not be used in the development of solid dosage forms containing BNZ.