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1.
Chemistry ; 30(11): e202302138, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-37957130

RESUMO

Three different devices: ball mill, hot stage melting, and magic angle spinning (MAS) NMR rotor were used for the preparation of ethenzamide (ET) cocrystals with glutaric acid (GLU), ethylmalonic acid (EMA) and maleic acid (MAL) as coformers. In each case, well-defined binary systems (ET:EMA, ET:GLU, ET:MAL) were obtained. The common features of the two solvent free methods of cocrystal formation (grinding, melting) are presented on the basis of arguments obtained by solid state NMR spectroscopy. Thermal analysis (Differential Scanning Calorimetry) proved that the eutectic phase arises over a wide range of molar ratios of components for each of the binary systems. NMR techniques, supported by theoretical calculations, allowed to provide details about the pathway of the reaction mechanism with atomic accuracy. It was found that the formation of ET cocrystals is a complex process that requires five steps. Each step has been recognized and described. Variable temperature 1D and 2D MAS NMR experiments allowed to track physicochemical processes taking place in a molten state. Moreover, it was found that in a multicomponent mixture consisting of all four components, ET, EMA, GLU, and MAL, ET in the molten phase behaves as a specific selector choosing only one partner to form binary cocrystals according to energy preferences. The process of exchange of coformers in binary systems during grinding, melting, and NMR measurements is described. The stabilization energies (Estab ) and molecular electrostatic potential (MEP) maps computed for the cocrystals under discussion and their individual components rationalize the selection rules and explain the relationships between individual species.

2.
Mol Pharm ; 21(6): 2838-2853, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38662637

RESUMO

Levofloxacin hemihydrate (LVXh) is a complex fluoroquinolone drug that exists in both hydrated and anhydrous/dehydrated forms. Due to the complexity of such a compound, the primary aim of this study was to investigate the amorphization capabilities and solid-state transformations of LVXh when exposed to mechanical treatment using ball milling. Spray drying was utilized as a comparative method for investigating the capabilities of complete LVX amorphous (LVXam) formation. The solid states of the samples produced were comprehensively characterized by powder X-ray diffraction, thermal analysis, infrared spectroscopy, Rietveld method, and dynamic vapor sorption. The kinetics of the process and the quantification of phases at different time points were conducted by Rietveld refinement. The impact of the different mills, milling conditions, and parameters on the composition of the resulting powders was examined. A kinetic investigation of samples produced using both mills disclosed that it was in fact possible to partially amorphize LVXh upon mechanical treatment. It was discovered that LVXh first transformed to the anhydrous/dehydrated form γ (LVXγ), as an intermediate phase, before converting to LVXam. The mechanism of LVXam formation by ball milling was successfully revealed, and a new method of forming LVXγ and LVXam by mechanical forces was developed. Spray drying from water depicted that complete amorphization of LVXh was possible. The amorphous form of LVX had a glass transition temperature of 80 °C. The comparison of methods highlighted that the formation of LVXam is thus both mechanism- and process-dependent. Dynamic vapor sorption studies of both LVXam samples showed comparable stability properties and crystallized to the most stable hemihydrate form upon analysis. In summary, this work contributed to the detailed understanding of solid-state transformations of essential fluoroquinolones while employing greener and more sustainable manufacturing methods.


Assuntos
Levofloxacino , Difração de Raios X , Levofloxacino/química , Difração de Raios X/métodos , Pós/química , Cinética , Composição de Medicamentos/métodos , Antibacterianos/química , Varredura Diferencial de Calorimetria/métodos , Cristalização , Química Farmacêutica/métodos
3.
Pharm Res ; 40(7): 1709-1722, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35460023

RESUMO

PURPOSE: To investigate the difference in methods to determine the osmolality in solutions of stabilizers used for long-acting injectable suspensions. METHODS: The osmolality was measured by freezing point depression and vapor pressure for 11 different polymers and surfactants (PEG 3350, 4000, 6000, 8000, 20,000, PVP K12, K17 and K30, poloxamer 188, 388 and 407, HPMC E5, Na-CMC, polysorbate 20 and 80, vitamin E-TPGS, phospholipid, DOSS and SDS) in different concentrations. RESULTS: Independently of the measuring method, an increase in osmolality with increasing concentration was observed for all polymers and surfactants, as would be expected due to the physicochemical origin of the osmolality. No correlation was found between the molecular weight of the polymers and the measured osmolality. The osmolality values were different for PVPs, PEGs, and Na-CMC using the two different measurement methods. The values obtained by the freezing point depression method tended to be similar or higher than the ones provided by vapor pressure, overall showing a significant difference in the osmolality measured by the two investigated methods. CONCLUSIONS: For lower osmolality values (e.g. surfactants), the choice of the measuring method was not critical, both the freezing point depression and vapor pressure could be used. However, when the formulations contained higher concentrations of excipients and/or thermosensitive excipients, the data suggests that the vapor pressure method would be more suited.


Assuntos
Depressão , Excipientes , Pressão de Vapor , Congelamento , Concentração Osmolar , Polímeros , Tensoativos
4.
Mol Pharm ; 19(8): 2980-2991, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35850530

RESUMO

Acid-base multicomponent systems have become a popular choice as a strategy to fine-tune the physicochemical properties of active pharmaceutical ingredients. Current prediction tools based on the principles of anticrystal engineering cannot always accurately predict the nature of intermolecular interactions within a multicomponent system. Even small changes in the physicochemical parameters of parent components can result in unexpected outcomes, and many salt, cocrystal, and ionic liquid forms are still being discovered empirically. In this work, we aimed to establish structural consistency in a series of mixtures comprising lidocaine (LID) with decanedioic, undecanedioic, dodecanedioic, and tridecanedioic acids and to explore how length and flexibility of the acid carbon backbone affect the molecular recognition, crystallization, and thermal behavior of the expected binary systems. We found that neat grinding of LID with dicarboxylic acids results in the formation of eutectic phases. The observed eutectic melting points deviated from the ideal eutectic temperatures predicted by the Schroeder van Laar model because of hydrogen bonding between the reacting components within the mixtures. Furthermore, thermal and infrared analysis provided evidence for the possible formation of new phases stemming from partial ionization of the counterions. Besides, the structure of a previously undetermined form I of the tridecanedioic acid was solved by single crystal X-ray diffraction.


Assuntos
Líquidos Iônicos , Lidocaína , Cristalização , Ácidos Dicarboxílicos , Ligação de Hidrogênio , Líquidos Iônicos/química , Lidocaína/química
5.
J Chem Educ ; 99(3): 1231-1237, 2022 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-35281210

RESUMO

Public engagement in medicine has become more important in promoting population health management and literacy. Medicine is a topic of great societal importance, and many public engagement activities have been developed to promote this area. However, they often narrowly focus on patient groups, diseases, a singular pharmaceutical drug or analytical technique. Despite the importance of these activities, general audiences are still heavily reliant on doctors and pharmacists for information about their medicine and lack basic knowledge around medication use and personal safety. Given this, a broader engagement approach is warranted to target health literacy among the wider public. "Medicine Maker" is a hands-on public engagement workshop that provides audiences with the opportunity to "manufacture" and inspect the quality of proxy or "dummy" medicine through guided inquiry. Here, we detail the development of the Medicine Maker workshop from its origins in the teaching of Irish third-level pharmacy students, to its initial application with a variety of lay audiences. Formal and informal feedback from participants indicates that the workshop can help foster a more critical understanding of medicine manufacturing, quality control, and personal health.

6.
Mol Pharm ; 18(8): 3050-3062, 2021 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-34250800

RESUMO

In this work, we employed broad-band dielectric spectroscopy to determine the solubility limits of nimesulide in the Kollidon VA64 matrix at ambient and elevated pressure conditions. Our studies confirmed that the solubility of the drug in the polymer matrix decreases with increasing pressure, and molecular dynamics controls the process of recrystallization of the excess of amorphous nimesulide from the supersaturated drug-polymer solution. More precisely, recrystallization initiated at a certain structural relaxation time of the sample stops when a molecular mobility different from the initial one is reached, regardless of the temperature and pressure conditions. Finally, based on the presented results, one can conclude that by transposing vertically the results obtained at elevated pressures, one can obtain the solubility limit values corresponding to low temperatures. This approach was validated by the comparison of the experimentally determined points with the theoretically obtained values based on the Flory-Huggins theory.


Assuntos
Química Farmacêutica/métodos , Espectroscopia Dielétrica/métodos , Composição de Medicamentos/métodos , Polímeros/química , Pressão , Sulfonamidas/química , Temperatura , Varredura Diferencial de Calorimetria/métodos , Cristalização , Estabilidade de Medicamentos , Pirrolidinas/química , Solubilidade , Soluções , Compostos de Vinila/química
7.
Langmuir ; 36(15): 4165-4173, 2020 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-32223171

RESUMO

Lipid nanocapsules (LNCs) are drug delivery platforms designed for different administration routes including intravenous delivery. Nanocarrier binding with plasma proteins such as albumin is an important factor that influences the pharmacokinetics of the drug and the drug delivery system. The aim of this paper was to characterize LNCs with different surface compositions and hydrophobicities to study their interactions with albumin: binary LNCs [oil-glyceryl trioctanoate (TG) and PEGylated surfactant macrogol 15-hydroxystearate (MHS)] and ternary LNCs (TG, MHS, and Span 80). Span was found to stabilize and decrease the LNC size. The formation of a stable LNC/albumin complex in the ground state was demonstrated. Thermodynamic parameters indicated that complex formation was exothermic and spontaneous, and the interactions involved van der Waals forces and hydrogen bond formation. Ternary LNCs showed higher affinity for albumin than did binary LNCs (affinity constant 10-fold higher). This study is the first report on the thermodynamic mechanisms that lead to the formation of a complex between albumin and organic nanoparticles with different surface architectures.


Assuntos
Nanocápsulas , Albuminas , Sistemas de Liberação de Medicamentos , Lipídeos , Termodinâmica
8.
AAPS PharmSciTech ; 20(5): 217, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31172323

RESUMO

The addition of matrix formers within a formulation provides a means for enhancing the redispersibility of nanoparticles (NPs) enabling them to retain their advantageous properties imparted onto them by their sub-micron size. In this work, NPs were isolated in the solid state via spray drying with a range of sugars. The processed powders were characterized, establishing that itraconazole (ITR) nanostructured microparticles (NMPs) spray dried in the presence of mannitol and trehalose had favorable redispersibility confirmed by dynamic light scattering and nanoparticle tracking analysis. Solid-state analysis confirmed the crystalline nature of NMPs based on mannitol and the amorphous character of trehalose-based NMPs. The NMPs powders were compacted at a range of pressures, producing tablets with high tensile strength without compromising their disintegration time. A greater amount of ITR was solubilized from trehalose NMPs compared to the mannitol-based compacts in 0.1 M HCl, showing a promise for enhanced in vivo activity. Overall, as trehalose exhibited superior carrier properties for ITR NMPs, this type of excipient included in the formulation warrants careful consideration. The structured approach to matrix former selection and tabletting studies can reduce the amount of material and time required for testing in the initial stages of product development.


Assuntos
Itraconazol/isolamento & purificação , Nanoestruturas/química , Dessecação , Excipientes/química , Itraconazol/química , Manitol/química , Tamanho da Partícula , Pós , Comprimidos , Resistência à Tração , Trealose/química
9.
Mol Pharm ; 15(11): 5192-5206, 2018 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-30252481

RESUMO

Liquid crystalline (LC) materials and their nonmedical applications have been known for decades, especially in the production of displays; however, the pharmaceutical implications of the LC state are inadequately appreciated, and the misunderstanding of experimental data is leading to possible errors, especially in relation to the physical stability of medicines. The aim of this work was to study LC phases of itraconazole (ITZ), an azole antifungal active molecule, and for the first time, to generate full thermodynamic phase diagrams for ITZ/polymer systems, taking into account isotropic and anisotropic phases that this drug can form. It was found that supercooled ITZ does not form an amorphous but a vitrified smectic (vSm) phase with a glass transition temperature of 59.35 °C (determined using a 10 °C/min heating rate), as is evident from X-ray diffraction and thermomicroscopic (PLM) experiments. Two endothermic LC events with the onset temperature values for a smectic to nematic transition of 73.2 ± 0.4 °C and a nematic to isotropic transformation at 90.4 ± 0.35 °C and enthalpies of transition of 416 ± 34 J/mol and 842 ± 10 J/mol, respectively, were recorded. For the binary supercooled mixtures, PLM and differential scanning calorimetry showed a phase separation with birefringent vSm persistent over a wide polymer range, as noticed especially for the hypromellose acetate succinate (HAS) systems. Both, smectic and nematic, phases were detected for the supercooled ITZ/HAS and ITZ/methacrylic acid-ethyl acrylate copolymer (EUD) mixtures, while geometric restrictions inhibited the smectic formation in the ITZ/poly(acrylic acid) (CAR) systems. The Flory-Huggins lattice theory coupled with the Maier-Saupe-McMillan approach to model anisotropic ordering of molecules was successfully utilized to create phase diagrams for all ITZ/polymer mixtures. It was concluded that in a supercooled ITR/polymer mix, if ITZ is present in a LC phase, immiscibility as a result of molecule anisotropy is afforded. This study shows that the LC nature of ITZ cannot be disregarded when designing stable formulations containing this molecule.


Assuntos
Antifúngicos/química , Composição de Medicamentos/métodos , Itraconazol/química , Cristais Líquidos/química , Anisotropia , Química Farmacêutica , Cristalização , Estabilidade de Medicamentos , Derivados da Hipromelose/química , Metacrilatos/química , Transição de Fase , Polímeros/química , Solubilidade , Temperatura de Transição
10.
Mol Pharm ; 15(5): 1928-1940, 2018 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-29584436

RESUMO

In this article we thoroughly investigated the physical stability of the amorphous form of a chloramphenicol drug. The tendency toward recrystallization of this drug has been examined (i) at nonisothermal conditions by means of a DSC technique; (ii) at isothermal conditions and temperature close to Troom by means of dielectric spectroscopy; (iii) at isothermal conditions and elevated temperatures of T = 323 K and 338 K by dielectric spectroscopy; and (iv) at conditions imitating the manufacturing procedure (i.e., elevated temperature and compression procedure). Our investigations have shown that amorphous chloramphenicol, stored at both standard storage and elevated temperature conditions, does not reveal a tendency toward recrystallization. However, compression significantly changes this behavior and destabilizes the examined compound. We found that due to chemical equilibration of the sample, the elongation of the storage time before compression might improve the physical stability of the examined pharmaceutical exposed to compression 34-times.


Assuntos
Cloranfenicol/química , Varredura Diferencial de Calorimetria/métodos , Cristalização/métodos , Espectroscopia Dielétrica/métodos , Estabilidade de Medicamentos , Armazenamento de Medicamentos/métodos , Simulação de Dinâmica Molecular , Pressão , Temperatura , Difração de Raios X/métodos
11.
Pharm Dev Technol ; 23(4): 343-350, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28145793

RESUMO

Copaiba oleoresin (CPO), obtained from Copaifera landgroffii, is described as active to a large number of diseases and more recently in the endometriosis treatment. In this work, poly(lactic-co-glycolic acid) (PLGA) nanoparticles containing CPO were obtained using the design of experiments (DOE) as a tool to optimize the production process. The nanoparticles optimized by means of DOE presented an activity in relation to the cellular viability of endometrial cells. The DOE showed that higher amounts of CPO combined with higher surfactant concentrations resulted in better encapsulation efficiency and size distribution along with good stability after freeze drying. The encapsulation efficiency was over 80% for all produced nanoparticles, which also presented sizes below 300 nm and spherical shape. A decrease in viability of endometrial stromal cells from ectopic endometrium of patients with endometriosis and from eutopic endometriotic lesions was demonstrated after 48 h of incubation with the CPO nanoparticles. The nanoparticles without CPO were not able to alter the cell viability of the same cells, indicating that this material was not cytotoxic to the tested cells and suggesting that the effect was specific to CPO. The results indicate that the use of CPO nanoparticles may represent a promising alternative for the treatment of endometriosis.


Assuntos
Portadores de Fármacos/química , Ácido Láctico/química , Nanopartículas/química , Preparações de Plantas/administração & dosagem , Ácido Poliglicólico/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Endometriose/tratamento farmacológico , Fabaceae/química , Feminino , Liofilização , Humanos , Tamanho da Partícula , Preparações de Plantas/química , Preparações de Plantas/farmacologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
12.
Mol Pharm ; 14(7): 2209-2223, 2017 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-28570079

RESUMO

Ciprofloxacin (CIP) is a poorly soluble drug that also displays poor permeability. Attempts to improve the solubility of this drug to date have largely focused on the formation of crystalline salts and metal complexes. The aim of this study was to prepare amorphous solid dispersions (ASDs) by ball milling CIP with various polymers. Following examination of their solid state characteristics and physical stability, the solubility advantage of these ASDs was studied, and their permeability was investigated via parallel artificial membrane permeability assay (PAMPA). Finally, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the ASDs were compared to those of CIP. It was discovered that acidic polymers, such as Eudragit L100, Eudragit L100-55, Carbopol, and HPMCAS, were necessary for the amorphization of CIP. In each case, the positively charged secondary amine of CIP was found to interact with carboxylate groups in the polymers, forming amorphous polymeric drug salts. Although the ASDs began to crystallize within days under accelerated stability conditions, they remained fully X-ray amorphous following exposure to 90% RH at 25 °C, and demonstrated higher than predicted glass transition temperatures. The solubility of CIP in water and simulated intestinal fluid was also increased by all of the ASDs studied. Unlike a number of other solubility enhancing formulations, the ASDs did not decrease the permeability of the drug. Similarly, no decrease in antibiotic efficacy was observed, and significant improvements in the MIC and MBC of CIP were obtained with ASDs containing HPMCAS-LG and HPMCAS-MG. Therefore, ASDs may be a viable alternative for formulating CIP with improved solubility, bioavailability, and antimicrobial activity.


Assuntos
Ciprofloxacina/química , Polímeros/química , Resinas Acrílicas/química , Metilcelulose/análogos & derivados , Metilcelulose/química , Testes de Sensibilidade Microbiana , Ácidos Polimetacrílicos/química , Solubilidade
14.
Mol Pharm ; 14(11): 3718-3728, 2017 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-28922604

RESUMO

Fluid bed coating offers potential advantages as a formulation platform for amorphous solid dispersions (ASDs) of poorly soluble drugs, being a one-step manufacturing process which could reduce the risk of phase separation associated with multiple step manufacturing approaches. However, the impact of the physicochemical nature of nonpareil carriers on the properties and drug release from the ASDs has not been studied in detail. In this work, tartaric acid (TAP) and microcrystalline cellulose (CEL) spheres were chosen as examples of functional and inert beads, respectively. Two structurally related triazole antifungals, itraconazole (ITR) and posaconazole (POS), were chosen as model drugs. Solid-state investigations revealed that the fluidized bed process result in both types of spheres uniformly coated with ITR and POS ASDs based on Eudragit L100-55 (EUD). A single glass transition temperature (Tg) was determined for each of the ASDs. Infrared studies suggested the presence of a weak interaction between POS and TAP, which translated into premature release of POS from the POS/EUD ASD coated TAP spheres in FaSSGF and subsequently lower POS cumulative release in comparison to the ASD coated on CEL beads. High resolution investigations of morphological and compositional changes during dissolution, using scanning electron microscopy and atomic force microscopy coupled with nanoscale thermal investigation, revealed that crystallization of the drug from the ASDs was induced during dissolution when TAP spheres were used as carriers. In contrast, ASDs coated on CEL underwent phase separation and drug-rich nanospecies were formed in the matrix due to the solubility gap between the drug and EUD in FaSSIF. This study demonstrates that properties of carrier for the ASD fundamentally affect the drug release properties and the proper selection of carrier beads is critical to ensure product quality.


Assuntos
Antifúngicos/química , Itraconazol/química , Triazóis/química , Celulose/química , Tartaratos/química
15.
Pharm Res ; 34(11): 2425-2439, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28875408

RESUMO

PURPOSE: To improve the pharmaceutical properties of amorphous ciprofloxacin (CIP) succinate salts via formulation as polymer/amorphous salt solid dispersions (ASSDs). METHODS: ASSDs consisting of an amorphous CIP/succinic acid 1:1 or 2:1 salt dispersed in PVP or Soluplus were produced by spray drying and ball milling. The solid state characteristics, miscibility, stability, solubility and passive transmembrane permeability of the ASSDs were then examined. RESULTS: The ASSDs had higher glass transition and crystallization temperatures than the corresponding amorphous succinate salts, and were also more stable during long-term stability studies. The results of inverse gas chromatography and thermal analysis indicated that the salts and polymers form a miscible mixture. The solubility of the pure drug in water and biorelevant media was significantly increased by all of the formulations. The permeability of the ASSDs did not differ significantly from that of the amorphous CIP succinate salts, however all samples were less permeable than the pure crystalline drug. CONCLUSIONS: The formulation of amorphous CIP succinate salts as ASSDs with polymer improved their long-term stability, but did not significantly affect their solubility or permeability.


Assuntos
Ciprofloxacina/química , Polietilenoglicóis/química , Polivinil/química , Povidona/química , Cloreto de Sódio/química , Química Farmacêutica/métodos , Cristalização , Dessecação , Composição de Medicamentos , Estabilidade de Medicamentos , Permeabilidade , Transição de Fase , Solubilidade , Temperatura
16.
J Am Chem Soc ; 137(3): 1157-64, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-25558882

RESUMO

Ionic systems with enhanced proton conductivity are widely viewed as promising electrolytes in fuel cells and batteries. Nevertheless, a major challenge toward their commercial applications is determination of the factors controlling the fast proton hopping in anhydrous conditions. To address this issue, we have studied novel proton-conducting materials formed via a chemical reaction of lidocaine base with a series of acids characterized by a various number of proton-active sites. From ambient and high pressure experimental data, we have found that there are fundamental differences in the conducting properties of the examined salts. On the other hand, DFT calculations revealed that the internal proton hopping within the cation structure strongly affects the pathways of mobility of the charge carrier. These findings offer a fresh look on the Grotthuss-type mechanism in protic ionic glasses as well as provide new ideas for the design of anhydrous materials with exceptionally high proton conductivity.


Assuntos
Lidocaína/química , Prótons , Condutividade Elétrica , Íons/química , Estrutura Molecular , Teoria Quântica
17.
Mol Pharm ; 12(9): 3468-78, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26275018

RESUMO

The external appearance of a crystal of active pharmaceutical ingredient (API), usually referred to as a crystal habit, has a substantial impact on the API's physicochemical and physiochemical properties and, subsequently, its pharmaceutical performance. In this work, we investigate the role of different parameters of antisolvent crystallization impacting on the itraconazole (ITR) crystal habit and how this crystal habit manipulation, including crystal intergrowth, can affect crystal interactions with water molecules. Three distinct isomorphic crystal habits of ITR, a twinned blade-shaped (CHtw), a plate-shaped (CHpl), and a flat sheet-shaped with dendritic ends (CHsh), were obtained by controlling crystallization conditions. A liquid-liquid crystalline phase separation was observed as an intermediate stage preceding crystal growth. The March-Dollase parameter was used as a quantitative description of the preferred orientation, where CHsh exhibited the highest preferred orientation. The three crystal habits were evaluated for their wettability and water vapor distribution, at 37 °C, using the Young-Nelson fitting model. CHtw crystals sorbed a statistically significantly higher amount of water than CHpl and CHsh, which was attributed to the presence of crystal defects due to the twinning boundary. On the other hand, the amount of water adsorbed on the surface of CHpl and CHsh crystals was comparable and it was about twice that adsorbed on CHtw crystals. This was related to the abundance of hydrophilic chemical functionalities on the (010) facet of CHpl and CHsh as supported by the full interaction map carried out using Mercury software. This study expands investigations of the impact of crystal habit manipulation on API's functional properties beyond the well-known solubility improvement approaches.


Assuntos
Inibidores do Citocromo P-450 CYP3A/química , Itraconazol/química , Cristais Líquidos/química , Solventes/química , Cristalização , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Solubilidade , Água/química , Molhabilidade
18.
Mol Pharm ; 12(9): 3408-19, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26214347

RESUMO

In this study, a comparison of different methods to predict drug-polymer solubility was carried out on binary systems consisting of five model drugs (paracetamol, chloramphenicol, celecoxib, indomethacin, and felodipine) and polyvinylpyrrolidone/vinyl acetate copolymers (PVP/VA) of different monomer weight ratios. The drug-polymer solubility at 25 °C was predicted using the Flory-Huggins model, from data obtained at elevated temperature using thermal analysis methods based on the recrystallization of a supersaturated amorphous solid dispersion and two variations of the melting point depression method. These predictions were compared with the solubility in the low molecular weight liquid analogues of the PVP/VA copolymer (N-vinylpyrrolidone and vinyl acetate). The predicted solubilities at 25 °C varied considerably depending on the method used. However, the three thermal analysis methods ranked the predicted solubilities in the same order, except for the felodipine-PVP system. Furthermore, the magnitude of the predicted solubilities from the recrystallization method and melting point depression method correlated well with the estimates based on the solubility in the liquid analogues, which suggests that this method can be used as an initial screening tool if a liquid analogue is available. The learnings of this important comparative study provided general guidance for the selection of the most suitable method(s) for the screening of drug-polymer solubility.


Assuntos
Acetaminofen/química , Celecoxib/química , Cloranfenicol/química , Estabilidade de Medicamentos , Felodipino/química , Indometacina/química , Polímeros/química , Varredura Diferencial de Calorimetria , Química Farmacêutica , Cristalização/métodos , Povidona/química , Pirrolidinonas/química , Solubilidade , Termodinâmica , Compostos de Vinila/química
19.
Pharm Res ; 32(1): 180-95, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25074469

RESUMO

PURPOSE: To formulate and investigate the physicochemical properties, physical stability and aerosolization characteristics of nanoporous/nanoparticulate microparticles (NPMPs) prepared by co-spray drying the sugars raffinose pentahydrate (R) or trehalose dihydrate (T) with the cyclic oligosaccharide hydroxypropyl-ß-cyclodextrin (HPßCD). METHODS: Production of powders was carried out using a laboratory scale spray dryer. The resulting powders were characterised by X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), laser diffraction particle sizing, specific surface area analysis (SSA), Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), dynamic vapour sorption (DVS) and aerodynamic assessment using a Next Generation Impactor (NGI). RESULTS: Powders were amorphous and composed of spherical, porous microparticles with reduced particle size and high specific surface area (~100 m(2)/g). DSC scans showed a single glass transition temperature. FTIR was indicative of the existence of molecular interactions between the carbohydrates. DVS analysis showed an increase in the critical relative humidity (RH) of raffinose and trehalose and eventual crystallization inhibition with increasing concentration of HPßCD. The in vitro deposition showed powders formulated with HPßCD had higher recovered emitted dose and fine particle fraction (<5 µm) than raffinose and trehalose spray dried alone. CONCLUSIONS: The co-spray drying of raffinose or trehalose with HPßCD results in powders with improved physicochemical characteristics, physical stability and aerodynamic behaviour compared to spray-dried raffinose/trehalose particles, constituting improved potential drug-carrier systems for pulmonary delivery.


Assuntos
Portadores de Fármacos/química , Nanopartículas/química , Rafinose/química , Tecnologia Farmacêutica/métodos , Trealose/química , beta-Ciclodextrinas/química , 2-Hidroxipropil-beta-Ciclodextrina , Aerossóis , Varredura Diferencial de Calorimetria , Cristalização , Estabilidade de Medicamentos , Inaladores de Pó Seco , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Porosidade , Pós , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Difração de Raios X
20.
Pharmaceutics ; 16(5)2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38794322

RESUMO

The co-administration of curcumin and hesperetin might be beneficial in terms of neuroprotective activity; therefore, in this study, we attempted to develop a fixed-dose formulation comprising these two compounds in an amorphous state. The aim of obtaining an amorphous state was to overcome the limitations of the low solubility of the active compounds. First, we assessed the possibility of using popular sweeteners (erythritol, xylitol, and sorbitol) as plasticizers to reduce the glass transition temperature of PVP K30 to prepare the polymer-excipient blends, which allowed the preparation of amorphous solid dispersions via hot-melt extrusion at a temperature below the original glass transition of PVP K30. Erythritol proved to be the superior plasticizer. Then, we focused on the development of fixed-dose amorphous solid dispersions of curcumin and hesperetin. Powder X-ray diffraction and thermal analysis confirmed the amorphous character of dispersions, whereas infrared spectroscopy helped to assess the presence of intermolecular interactions. The amorphous state of the produced dispersions was maintained for 6 months, as shown in a stability study. Pharmaceutical parameters such as dissolution rate, solubility, and in vitro permeability through artificial membranes were evaluated. The best improvement in these features was noted for the dispersion, which contained 15% of the total content of the active compounds with erythritol used as the plasticizer.

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