Preparation of drug polymorphs (a review)

Guranda, D. T.; Гильдеева, Г. Н.

doi:10.1007/s11094-010-0443-4

Cited by 13 publications

(7 citation statements)

References 72 publications

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“…Novel processes for the preparation of different polymorphs, apart from crystallization, are patented and published . Appropriate characterization techniques are needed to guide a chemist in the selection of a polymorph for final development after the discovery of polymorphic species.…”

Section: Introductionmentioning

confidence: 99%

Necessity of Establishing Chemical Integrity of Polymorphs of Drug Substance Using a Combination of NMR, HPLC, Elemental Analysis, and Solid-State Characterization Techniques: Case Studies

Sawant

Naik

2013

Org. Process Res. Dev.

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Polymorphism is a solid-state phenomenon; hence, solid-state techniques such as XRPD, DSC, and FT-IR are used for characterization. Many a time, only XRPD is used. These techniques ignore the most important aspects, i.e., chemical purity and the chemical integrity of the polymorph, which can be confirmed by techniques such as 1 H NMR, HPLC, and elemental analysis. The aim of this article is to emphasize how techniques such as 1 H NMR, elemental analysis, and HPLC purity in addition to other solid-state characterization techniques would help to prove that the drug really exists in different polymorphic forms. H 1 NMR, HPLC, and elemental analysis reveal the formation of different compounds and not polymorphs in the case of pioglitazone•HCl and glyburide. In the cases of irbesartan and ropinirole•HCl use of a single solid-state characterization technique such as XRPD is not enough for establishing the existence of different polymorphic forms.

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Section: Introductionmentioning

confidence: 99%

Necessity of Establishing Chemical Integrity of Polymorphs of Drug Substance Using a Combination of NMR, HPLC, Elemental Analysis, and Solid-State Characterization Techniques: Case Studies

Sawant

Naik

2013

Org. Process Res. Dev.

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“…Usually, different polymorphic forms possess different physicochemical and, as a consequence, biological properties (bioavailability, dissolution rate, etc. ). − An undesired polymorphic transition can crucially influence the drug quality as occurred with ritonavir (the trademark is Norvir) . Therefore, an in-depth study of the polymorphism of an active pharmaceutical ingredient (API) aims not only at protecting the patent of a drug but also at choosing the most appropriate polymorphic form according to the combination of several factors such as manufacturability, stability, biological activity, reproducibility, etc. , …”

Section: Introductionmentioning

confidence: 99%

High-Pressure Influence on Piracetam Crystals: Studying by Quantum Chemical Methods

Vaksler

Idriss

Shishkina

2021

Crystal Growth & Design

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The method developed previously for studying mechanical properties using quantum chemical calculations was applied to predict the most probable direction of deformation of the piracetam polymorphic Form II under pressure. By the analysis of the pairwise interaction energies between molecules in Form II, this structure was classified as columnar-layered. The shear deformation modeling of the strongly bound fragments in crystal packing predicted the [100] crystallographic direction with a shift energy barrier of 5.2 kcal/mol to be the most probable within the (001) crystallographic plane for Form II deformation. Comparison of Form II before the polymorphic transition and Form V after the crystal structure change confirmed the results of quantum chemical modeling. The analysis of the shift energy profile indicated the characteristic features (a local minimum near the starting point, negative interaction energies between layers during the displacement, and a low shift energy barrier) that can be used to predict a polymorphic transition. The study of the pairwise interaction energies in the piracetam Forms II and V under pressure has revealed that the crystal structure can be changed under pressure in two stages. In the first stage, the polymorphic transition occurs due to the shift of weakly bound layers without changing the columnar-layered type of the crystal structure from the energetic viewpoint. In the second stage, a change in the ratio of the interaction energies between BSM1 and BSM2 results in the transition of the crystal structure type from columnar-layered to columnar without changing the polymorphic form.

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“…In many cases, crystallization from different solvents brings about the formation of different polymorphs. ,, It is known that variation of molecular positions and/or molecular conformation inside three-dimensional (3D) crystalline space brings significant variation of crystal properties. In the case of pharmaceutically active compounds, it is important to mention the differences in polymorph thermal stability, melting points, solubility, and bioavailability. − For potential nonlinear optical (NLO) polymorphic materials, thermal stability is also important, but in this case, the molecular packing mode in crystals is more important since only acentric crystals can produce second-order NLO effects. − The influence of molecular packing in polymorphs on electrical, magnetic, and spectral properties are important for many materials, including charge transfer (CT) materials, that can be used in organic light-emitting diodes (OLEDs), photovoltaic, and biomedical devices. − …”

Section: Introductionmentioning

confidence: 99%

Polymorphism of Merocyanine Dyes Homologues with 1,3-Diethyl-2-thiobarbituric Acid Acceptor and p-Dimethylaminobenzene Donor and Different Polymethine Chains Connecting Them

Rigin

Tillotson

Perry

et al. 2019

Crystal Growth & Design

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The crystallization from different solvents of homologues of 1,3-diethyl-2-thiobarbituric acid and pdimethylaminobenzene with different lengths of the polymethine bridge between donor and acceptor groups (TB[n]) produced three pairs of polymorphs with the number of CC bonds in the chain n = 1, 3, and 5. The homologues with the shortest (one methine unit) π-conjugated bridge were presented by two concomitant (obtained simultaneously) polymorphs. Bond length alternation values calculated using X-ray data and evaluation using NMR data showed that some homologues possesses a very high hyperpolarizability. It was shown that the increase of polarizability is related to the increase in the length of the π-conjugated bridge that was supported by experimental hyper-Rayleigh scattering data. Density functional theory calculations of HOMO/LUMO molecular energy levels indicated that compounds with a longer π-conjugated bridge have a higher thermal stability.

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Preparation of drug polymorphs (a review)

Cited by 13 publications

References 72 publications

Necessity of Establishing Chemical Integrity of Polymorphs of Drug Substance Using a Combination of NMR, HPLC, Elemental Analysis, and Solid-State Characterization Techniques: Case Studies

Necessity of Establishing Chemical Integrity of Polymorphs of Drug Substance Using a Combination of NMR, HPLC, Elemental Analysis, and Solid-State Characterization Techniques: Case Studies

High-Pressure Influence on Piracetam Crystals: Studying by Quantum Chemical Methods

Polymorphism of Merocyanine Dyes Homologues with 1,3-Diethyl-2-thiobarbituric Acid Acceptor and p-Dimethylaminobenzene Donor and Different Polymethine Chains Connecting Them

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