title: Differential surface properties of commercial crystalline telmisartan samples.
abstract: The aim of the present study was to investigate differences in surface chemistry of commercially available telmisartan (TMS) samples in Indian market and to correlate them to the surface molecular environment. Comprehensive characterization of material properties of four TMS samples from different sources showed that all samples exhibited same polymorphic form, but different particle shape, particle size distribution, surface energetics and surface chemistry. Wettability and surface free energy were determined using sessile drop contact angle technique. TMS samples exhibited significant variations in their wetting behavior. The role of crystal shape, particle size distribution, surface energetics and surface chemistry in controlling TMS powder wettability was collectively explored by contact angle experiments. Evaluation of work of adhesion (Wa), immersion (Wi) and spreading (Ws) indicated that samples had differential wetting behavior. The surface chemistry was elucidated by X-ray photoelectron spectroscopy (XPS). The surface polarity index was determined by XPS and expressed as (oxygen+nitrogen)-to-(carbon) atomic concentration ratio. It was found to be different for all four TMS samples. Crystal morphology of TMS polymorph A was predicted using Bravais-Friedel Donnay-Harker (BFDH) method. Molecular lipophilic surface potential (MLSP) data for TMS showed the varied surface lipophilic environment throughout the molecule. Hence it can be concluded that the differential abundance of surface elements play an important role in controlling the biopharmaceutical performance of TMS powder samples.
authors: Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), SAS Nagar, Punjab 160 062, India.
authors: Preksha
authors: P
authors: Laad
authors: Ganesh
authors: G
authors: Shete
authors: Sameer R
authors: SR
authors: Modi
authors: Arvind Kumar
authors: AK
authors: Bansal
mesh_terms: D047228:Angiotensin II Type 1 Receptor Blockers / Q000737:chemistry*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry*; D000959:Antihypertensive Agents / Q000737:chemistry*; D001562:Benzimidazoles / Q000737:chemistry*; D001565:Benzoates / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D008855:Microscopy, Electron, Scanning; D033362:Powder Diffraction; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D000077333:Telmisartan; D013818:Thermogravimetry; D017155:Wettability; D014961:X-Ray Diffraction
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D001562:Benzimidazoles; D001565:Benzoates; D000077333:Telmisartan