Innovative Approaches to Characterizing Disordered Pharmaceuticals

A special issue of Pharmaceutics (ISSN 1999-4923). This special issue belongs to the section "Physical Pharmacy and Formulation".

Deadline for manuscript submissions: closed (31 March 2021) | Viewed by 3513

Special Issue Editors


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Guest Editor
Faculty of Science and Technology, Institute of Physics, University of Silesia, SMCEBI, 75 Pułku Piechoty 1a, 41-500 Chorzów, Poland
Interests: pharmaceutical sciences; amorphous pharmaceuticals; molecular dynamics; dielectric spectroscopy

E-Mail Website
Guest Editor
Faculty of Science and Technology, Institute of Physics, University of Silesia, SMCEBI, 75 Pułku Piechoty 1a, 41-500 Chorzów, Poland
Interests: high pressure; amorphous, glass transition; ionic liquids; dielectric spectroscopy

Special Issue Information

Dear Colleagues,

Nearly 90% of the promising candidates for active pharmaceutical ingredients (APIs), as well as over 40% of APIs sold in solid form, are characterized by low aqueous solubility. The scale of this problem is alarming, especially once one realizes that the vast majority of pharmaceuticals currently taken by patients worldwide are less soluble than a piece of a marble statue (solubility of 13 vs. 0.63 mg/L for marble, i.e., calcium carbonate, and atorvastatin drug, respectively). The low solubility of APIs results in their low bioavailability. Consequently, patients need to take a much higher dose of medications in comparison to the amount that effectively works on them. Having this in mind, scientists from over 20 years working on better soluble—fully or partially amorphous—forms of APIs. Even though more and more products with an amorphous core have reached the market in the past few years, disordered materials are still a puzzle to be solved. All mechanisms governing their tendency toward recrystallization have not been discovered yet. Consequently, there is no universal approach that would help in assessing the physical stability of such systems at both standard storage and manufacturing conditions. According to the current state of knowledge, each disordered API should be treated individually. Therefore, this Special Issue of Pharmaceutics aims to collect new ideas and innovative strategies that will help toward quicker development and characterization of amorphous drug formulations.

Dr. Justyna Knapik-Kowalczuk
Prof. Dr. Marian Paluch
Guest Editors

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Keywords

  • amorphous pharmaceuticals
  • poorly soluble drugs
  • physical stability
  • recrystallization inhibition
  • amorphous solid dispersions
  • mesoporous silica
  • co-amorphous
  • hot melt extrusion

Published Papers (1 paper)

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Research

10 pages, 1148 KiB  
Article
Structural Polymorphism of Sorafenib Tosylate as a Key Factor in Its Solubility Differentiation
by Gabriela Wiergowska, Anna Stasiłowicz, Andrzej Miklaszewski, Kornelia Lewandowska and Judyta Cielecka-Piontek
Pharmaceutics 2021, 13(3), 384; https://doi.org/10.3390/pharmaceutics13030384 - 13 Mar 2021
Cited by 7 | Viewed by 3146
Abstract
The presence of active pharmaceutical ingredients (APIs) in the forms of different polymorphic states can induce differences in their physicochemical properties. In the case of poorly soluble APIs, like the oncological drug sorafenib tosylate, small variations in solubility may result in large bioavailability [...] Read more.
The presence of active pharmaceutical ingredients (APIs) in the forms of different polymorphic states can induce differences in their physicochemical properties. In the case of poorly soluble APIs, like the oncological drug sorafenib tosylate, small variations in solubility may result in large bioavailability differences. The control of its therapeutic dose is crucial from the effective pharmacotherapy point of view and the reduction of side effects. Therefore, this study aimed to assess the influence of sorafenib tosylate polymorphic forms on its solubility and, consequently, permeability, based on passive diffusion through membranes simulating the gastrointestinal tract (GIT) conditions. In the first part of the work, two crystalline forms of sorafenib tosylate were identified using the X-ray powder diffraction, FT-IR, and Raman spectroscopy. Subsequently, solubility studies were carried out. Both forms of sorafenib tosylate were insoluble in 0.1 N hydrochloric acid (HCl), in acetate buffer (pH 4.5), and in phosphate buffer (pH 6.8). Solubility (mg/mL) of form I and III of sorafenib tosylate in 0.1 N HCl + 1.0% SDS was 0.314 ± 0.006 and 1.103 ± 0.014, respectively, in acetate buffer pH 4.5 + 1.0% SDS it was 2.404 ± 0.012 and 2.355 ± 0.009, respectively, and in phosphate buffer pH 6.8 + 1.0% SDS it was 0.051 ± 0.005 and 1.805 ± 0.023, respectively. The permeability study was assessed using the parallel artificial membrane permeability assay (PAMPA) model. The apparent permeability coefficient (Pappcm s−1) of form I and III in pH 1.2 was 3.01 × 10−5 ± 4.14 × 10−7 and 3.15 × 10−5 ± 1.89 × 10−6, respectively, while in pH 6.8 it was 2.72 × 10−5 ± 1.56 × 10−6 and 2.81 × 10−5 ± 9.0 × 10−7, respectively. Changes in sorafenib tosylate concentrations were determined by chromatography using the high-performance liquid chromatography (HPLC)–DAD technique. As a result of the research on the structural polymorphism of sorafenib tosylate, its full spectral characteristics and the possibility of using FT-IR and Raman spectroscopy for the study of polymorphic varieties were determined for the first time, and the HPLC method was developed, which is appropriate for the assessment of sorafenib solubility in various media. The consequences of various physicochemical properties resulting from differences in the solubility of sorafenib tosylate polymorphs are important for pre-formulation and formulation studies conducted with its participation and for the safety of oncological sorafenib therapy. Full article
(This article belongs to the Special Issue Innovative Approaches to Characterizing Disordered Pharmaceuticals)
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