scholarly journals Selective preparation of elusive and alternative single component polymorphic solid forms through multi-component crystallisation routes

2016 ◽  
Vol 52 (46) ◽  
pp. 7372-7375 ◽  
Author(s):  
Lynne H. Thomas ◽  
Craig Wales ◽  
Chick C. Wilson
Keyword(s):  
Self Assembly ◽  
Single Component ◽  
The Self ◽  
Active Pharmaceutical Ingredients ◽  
Simple Route ◽  
Pharmaceutical Ingredients ◽  
Crystallisation Process ◽  
Polymorphic Forms

A transferable, simple, route to previously elusive and novel polymorphic forms of important active pharmaceutical ingredients is demonstrated using N-heterocyclic co-molecules to influence the self-assembly crystallisation process in a multi-component environment.

scholarly journals Self-assembled sorbitol-derived supramolecular hydrogels for the controlled encapsulation and release of active pharmaceutical ingredients

2015 ◽  
Vol 51 (35) ◽  
pp. 7451-7454 ◽  
Author(s):  
Edward J. Howe ◽  
Babatunde O. Okesola ◽  
David K. Smith
Keyword(s):  
Drug Release ◽  
Controlled Drug Release ◽  
The Self ◽  
Active Pharmaceutical Ingredients ◽  
Supramolecular Hydrogel ◽  
Pharmaceutical Ingredients ◽  
Inflammatory Drugs ◽  
Anti Inflammatory ◽  
Self Assembled ◽  
Ph Controlled

A simple supramolecular hydrogel is able to extract acid-functionalised anti-inflammatory drugs via directed interactions with the self-assembled gel nanofibres and exhibits pH-controlled drug release.

Polymorphism of tubulin assembly in vitro

1989 ◽  
Vol 94 (3) ◽  
pp. 479-488
Author(s):  
PAULA KARECLA ◽  
ELIZABETH HIRST ◽  
PETER BAYLEY
Keyword(s):  
Self Assembly ◽  
Basic Structure ◽  
Limited Range ◽  
The Self ◽  
Tubulin Dimer ◽  
Thin Sectioning ◽  
Associated Proteins ◽  
Bona Fide ◽  
Polymorphic Forms

Polymorphism in the self-assembly of tubulin dimer and microtubule protein (tubulin plus the microtubule-associated proteins) has been investigated as a function of systematic variation of solution composition (i.e. buffer ion, [glycerol] and [Mg2+]). The nature of the assembly product was examined using negative staining and thin sectioning electron microscopy. The morphology of the product of assembly of tubulin dimer was found to be strongly influenced by the concentration of glycerol and Mg2+ in Pipes and Mes buffers; the effects are less marked in phosphate buffer. Formation of bona fide microtubules in O.l M-Pipes occurs for a limited range of solution conditions (e.g. with [glycerol] <2 M and [Mg2+]<1mM). Conditions of elevated [glycerol] and [Mg2+], which enhance the rate and extent of assembly, have the adverse effect of strongly promoting the formation of polymorphic forms in addition to, and in place of, the normal microtubule morphology. In both Pipes and Mes buffers, increasing [glycerol] from 1 to 3 M favours the formation of extended multiply curved sheets, apparently made up from a basic structure with an S-like crosssection. By contrast, increasing [Mg2+] promotes the formation of junctions between microtubule walls, giving products whose cross-section shows multiple hook-like appendages, attached to closed microtubules. The assembly of tubulin dimer in a typical ‘dimer assembly buffer’ (e.g. 0.05-0.1 MMes, with 1–3.4M-glycerol and 2–7mM-Mg2+), invariably produces substantial proportions of nonmicrotubule structures such as open sheets, ribbons, and hooked structures. We conclude that the self-assembly of tubulin dimer exclusively into bona fide microtubules occurs over a very restricted range of solution conditions in the normally used Pipes- and Mes-based buffers. Deviation from these conditions readily promotes the formation of mixtures of polymorphic forms. Many buffer systems used for the assembly and disassembly of microtubules composed of tubulin dimer appear likely to promote the formation of structures related to, but significantly different from, normal microtubules. This represents a cautionary factor in the interpretation of in vitro assembly and disassembly properties of microtubules

scholarly journals Antimicrobial preservation efficacy of liquid glucose and liquid maltitol syrups with and without 0.1% sorbic acid

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Thomas Carpentier ◽  
Eve Maillard ◽  
Mathilde Royer ◽  
Lina Mustapha ◽  
Frédéric Marçon
Keyword(s):  
Shelf Life ◽  
Sorbic Acid ◽  
The Self ◽  
Active Pharmaceutical Ingredients ◽  
Liquid Formulation ◽  
European Pharmacopoeia ◽  
Acceptance Criteria ◽  
Pharmaceutical Ingredients ◽  
Aspergillus Brasiliensis ◽  
Glucose Syrup

Abstract Objectives Amongst paediatric pharmaceutical forms, syrups offer advantages such as ease of administration and good palatability. They also exhibited microbial self-preservation properties that may be useful to enhance shelf life of liquid formulation. The objective of our works is to test the self-preservation efficacy of maltitol and glucose syrup without or with sorbic acid as described in the European pharmacopoeia. Methods The European Pharmacopoeia test of antimicrobial preservation efficacy was performed on liquid glucose syrup and liquid maltitol syrup with and without 0.1% sorbic acid. Results Unpreserved glucose and maltitol syrups did not meet the European Pharmacopoeia acceptance criteria for antimicrobial preservative efficacy due to the regrowth of Aspergillus brasiliensis on day 28 whereas glucose and maltitol syrups with 0.1% sorbic acid pass the test. Conclusions The addition of a preservative (sorbic acid) in glucose and maltitol syrups allows the validation of the antimicrobial preservative efficacy test of the European Pharmacopoeia. Further tests are needed to see if preservative efficacy is maintained despite dilutions or in the presence of active pharmaceutical ingredients.

scholarly journals Interplay between Polymorphism and Isostructurality in the 2-Fur- and 2-Thenaldehyde Semi- and Thiosemicarbazones

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 993
Author(s):  
Marcin Swiatkowski ◽  
Agata Trzesowska-Kruszynska ◽  
Agnieszka Danielewicz ◽  
Paulina Sobczak ◽  
Rafal Kruszynski
Keyword(s):  
Crystal Structures ◽  
Electron Density ◽  
Self Assembly ◽  
Crystal Packing ◽  
The Self ◽  
Polymorphic Forms ◽  
Full Interaction ◽  
Crystal Packing Effects ◽  
Packing Effects

The four compounds, namely: 5-nitro-2-furaldehyde thiosemicarbazone (1); 5-nitro-2-thiophene thiosemicarbazone (2); 5-nitro-2-furaldehyde semicarbazone (3); and 5-nitro-2-thiophene semicarbazone (4) were synthesized and crystallized. The three new crystal structures of 1, 2, and 4 were determined and compared to three already known crystal structures of 3. Additionally, two new polymorphic forms of 1 solvate were synthesized and studied. The influence of the exchange of 2-thiophene to 2-furaldehyde as well as thiosemicarbazone and semicarbazone on the self-assembly of supramolecular nets was elucidated and discussed in terms of the formed synthons and assemblies accompanied by Full Interaction Maps analysis. Changes in the strength of IR oscillators caused by the molecular and crystal packing effects are described and explained in terms of changes of electron density.

scholarly journals The Lisbon Supramolecular Green Story: Mechanochemistry towards New Forms of Pharmaceuticals

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2705
Author(s):  
João Luís Ferreira da Silva ◽  
M. Fátima Minas da Piedade ◽  
Vânia André ◽  
Sofia Domingos ◽  
Inês C. B. Martins ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Physicochemical Properties ◽  
Mechanochemical Synthesis ◽  
Crystal Engineering ◽  
Short Review ◽  
Active Pharmaceutical Ingredients ◽  
Pharmaceutical Ingredients ◽  
Polymorphic Forms ◽  
Derivatives Of

This short review presents and highlights the work performed by the Lisbon Group on the mechanochemical synthesis of active pharmaceutical ingredients (APIs) multicomponent compounds. Here, we show some of our most relevant contributions on the synthesis of supramolecular derivatives of well-known commercial used drugs and the corresponding improvement on their physicochemical properties. The study reflects, not only our pursuit of using crystal engineering principles for the search of supramolecular entities, but also our aim to correlate them with the desired properties. The work also covers our results on polymorphic screening and describes our proposed alternatives to induce and maintain specific polymorphic forms, and our approach to avoid polymorphism using APIs as ionic liquids. We want to stress that all the work was performed using mechanochemistry, a green advantageous synthetic technique.

Graphene oxide-based composite hydrogels with self-assembled macroporous structures

RSC Advances ◽  
2016 ◽  
Vol 6 (5) ◽  
pp. 3561-3570 ◽  
Author(s):  
Yiwan Huang ◽  
Ming Zeng ◽  
Zijian Feng ◽  
Die Yin ◽  
Qingyu Xu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Self Assembly ◽  
The Self ◽  
Simple Route ◽  
Composite Hydrogels ◽  
Assembly Technique ◽  
Self Assembled

The self-assembly technique provides a new and simple route for designing porous hydrogels.

scholarly journals Enabling precision manufacturing of active pharmaceutical ingredients: workflow for seeded cooling continuous crystallisations

2018 ◽  
Vol 3 (3) ◽  
pp. 518-549 ◽  
Author(s):  
Cameron J. Brown ◽  
Thomas McGlone ◽  
Stephanie Yerdelen ◽  
Vijay Srirambhatla ◽  
Fraser Mabbott ◽  
...  
Keyword(s):  
Process Design ◽  
Active Pharmaceutical Ingredients ◽  
Precision Manufacturing ◽  
Tight Control ◽  
Pharmaceutical Ingredients ◽  
Crystallisation Process

Presentation and applied case study of a system-wide workflow which supports rapid, systematic and efficient continuous seeded cooling crystallisation process design, with the aim to deliver a robust, consistent process with tight control of particle attributes.

The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

1971 ◽  
Vol 29 ◽  
pp. 366-367
Author(s):  
M. Kessel ◽  
R. MacColl
Keyword(s):  
Self Assembly ◽  
Analytical Ultracentrifugation ◽  
Uranyl Acetate ◽  
The Self ◽  
Major Protein ◽  
Subunit Structure ◽  
Blue Green Alga ◽  
Thin Sections ◽  
Blue Green Algae ◽  
Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

Interrelationship of the cellular distribution and secretion of regular structure (RS) protein in Bacillus licheniformis nm 105

1992 ◽  
Vol 50 (1) ◽  
pp. 712-713
Author(s):  
Xiaorong Zhu ◽  
Richard McVeigh ◽  
Bijan K. Ghosh
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Licheniformis ◽  
Self Assembly ◽  
Gel Electrophoresis ◽  
Culture Supernatant ◽  
Regular Structure ◽  
The Self ◽  
Cellular Distribution ◽  
Structural Protein ◽  
Laboratory Cultures

A mutant of Bacillus licheniformis 749/C, NM 105 exhibits some notable properties, e.g., arrest of alkaline phosphatase secretion and overexpression and hypersecretion of RS protein. Although RS is known to be widely distributed in many microbes, it is rarely found, with a few exceptions, in laboratory cultures of microorganisms. RS protein is a structural protein and has the unusual properties to form aggregate. This characteristic may have been responsible for the self assembly of RS into regular tetragonal structures. Another uncommon characteristic of RS is that enhanced synthesis and secretion which occurs when the cells cease to grow. Assembled RS protein with a tetragonal structure is not seen inside cells at any stage of cell growth including cells in the stationary phase of growth. Gel electrophoresis of the culture supernatant shows a very large amount of RS protein in the stationary culture of the B. licheniformis. It seems, Therefore, that the RS protein is cotranslationally secreted and self assembled on the envelope surface.

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