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Drug Substance and Excipient Characterization
Published in Dilip M. Parikh, Handbook of Pharmaceutical Granulation Technology, 2021
Parind M. Desai, Lai Wah Chan, Paul Wan Sia Heng
In this method, the polymorphs are identified by their thermal behaviors. The change in energy or related property of the polymorph as it undergoes a transformation when heated is recorded as a thermogram (Figure 3.9). The thermogram consists of characteristic peaks, including melting point (Tm) and glass transition temperature (Tg). The peaks pointing downward indicate endothermic changes, such as melting, sublimation, and desolvation. The different polymorphs of material will exhibit different thermograms, which allow them to be identified. Differential scanning calorimetry (DSC) and differential thermal analysis are two methods of thermal analyses that are commonly used. The sample is sealed in an aluminum pan and placed inside the test chamber where it is subjected to different heating rates. In DSC, the change in heat energy resulting from the crystalline transformation is recorded as a function of temperature. In the differential thermal analysis, the energy is expressed by differential temperature (sample vs. inert substance).
Thermal Analysis
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
Another mode of differential thermal analysis exists that is referred to as differential scanning calorimetry (Figure 2). With some instrumental designs, this terminology refers to refinements in the design of DTA systems so that data can be obtained in more quantitative and reproducible ways. The earlier use of the DSC terminology, which is still in use, referred to a system in which the calories required to maintain a constant temperature difference between a sample and a reference were directly measured. This was accomplished by measuring the amperage flowing into small heaters next to the sample, the flow of amperes so controlled as to be proportional to developing temperature differences. In this manner a direct measurement of the calories involved was obtained.
Thermal Analysis of Herbal Drugs
Published in Ravindra Kumar Pandey, Shiv Shankar Shukla, Amber Vyas, Vishal Jain, Parag Jain, Shailendra Saraf, Fingerprinting Analysis and Quality Control Methods of Herbal Medicines, 2018
Ravindra Kumar Pandey, Shiv Shankar Shukla, Amber Vyas, Vishal Jain, Parag Jain, Shailendra Saraf
In Differential Thermal Analysis, the temperature difference that develops between a sample and an inert reference material is measured when both are subjected to identical heat treatments. The related technique of Differential Scanning Calorimetry relies on differences in energy required to maintain the sample and reference at an identical temperature. The analytical method for recording the difference in temperature (T) of a substance and an inert reference material as a function of temperature or time and any transformation change in specific heat or an enthalpy of transition can be detected by DTA (Brandão et al., 2016).
Development of Darunavir proliposome powder for oral delivery by using Box–Bhenken design
Published in Drug Development and Industrial Pharmacy, 2020
Sachin Bhusari, Irfan Ansari, Avinash Chaudhary
Differential thermal analysis and DTG analysis of DRV, Blank physical mixture, physical mixture, blank OPP, and optimized batch A (OB-A) were carried out. 5 mg of each sample was taken for DTA & DTG analysis. DRV shows the peak temperature of 70.19 °C, onset temperature 58.12 °C and endset temperature of 82.15 °C (Figure 6) results in the thermal degradation of the DRV whereas, OPP formulation shows peak temperature of 170.64 °C, onset temperature 166.79 °C and endset temperature of 182.99 °C (Figure 6). In OPP absence of DRV peak indicates the entrapment of DRV into the liposomes vesicles. The descending DTG thermal curve results in weight loss of DRV. About −0.985 mg of weight loss of DRV occurs at a temperature range of 40.34–300.62 °C in 25.68 min whereas, in OPP formulation −1.45 mg of weight loss occurs at a temperature range of 226.35–300.48 °C in 25.74 min, as indicated in Table 4. The DTA and TGA analysis result in the thermal behavior of the DRV and OPP formulation.
Essential oils in niosomes for enhanced transdermal delivery of felodipine
Published in Pharmaceutical Development and Technology, 2019
Rania K. Eid, Ebtessam A. Essa, Gamal M. El Maghraby
Thermal analysis was employed to probe any possible interaction between the essential oils and the vesicular membrane. This study was achieved using differential thermal analyzer supplied by Shimadzu (Shimadzu DTA–50 module, Kyoto, Japan). The vesicular dispersion was subjected to an ultracentrifugation at 15 000 rpm (SIGMA 3–30 K, SIGMA Laborzentrifugen, Osterode am Harz, Germany) to separate the concentrated pellet which was subjected to thermal analysis. The pellet (about 3.5 mg) was loaded into the pans before being crimped using Shimadzu crimper before thermal analysis with empty pan serving as reference. The thermal behavior of each sample was monitored at a heating rate of 10 °C/min covering the temperature range of 25–200 °C. The equipment was operated under a continuous flow of dry nitrogen 15 ml/min. The transition midpoint (Tm) was recorded for each peak.
Preparation, characterization and dynamical mechanical properties of dextran-coated iron oxide nanoparticles (DIONPs)
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Hatice Kaplan Can, Serap Kavlak, Shahed ParviziKhosroshahi, Ali Güner
This work expresses the effort to understand the preparation of DIONPs in situ co-precipitation methods and nature of the interaction mechanism and thermal stability of dextran with iron oxide. This study describes the synthesis route of DIONPs and physical properties characterization by using XRD and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The thermal analysis was examined by differential scanning calorimetry (DSC), differential thermal analysis (DTA) and thermal gravimetric analysis (TGA). Dynamical mechanical properties of magnetic dextran nanoparticles were analysed by dynamic mechanical analysis (DMA).