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1.
Anal Bioanal Chem ; 408(1): 251-63, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26454443

RESUMO

Hair is a highly relevant specimen that is used to verify drug exposure in victims of drug-facilitated crime (DFC) cases. In the present study, a new analytical method involving ultrahigh-performance liquid chromatography-tandem mass spectrometry was developed for determining the presence of model drugs, including zolazepam and tiletamine and their metabolites in hair specimens from DFCs. The incorporation of zolazepam and tiletamine into hair after a single exposure was investigated in Long-Evans rats with the ratio of the hair concentration to the area under the curve. For rapid and simple sample preparation, methanol extraction and protein precipitation were performed for hair and plasma, respectively. No interference was observed in drug-free hair or plasma, except for hair-derived diphenhydramine in blank hair. The coefficients of variance of the matrix effects were below 12%, and the recoveries of the analytes exceeded 70% in all of the matrices. The precision and accuracy results were satisfactory. The limits of quantification ranged from 20 to 50 pg in 10 mg of hair. The drug incorporation rates were 0.03 ± 0.01% for zolazepam and 2.09 ± 0.51% for tiletamine in pigmented hair. We applied the present method to real hair samples in order to determine the drug that was used in seven cases. These results suggest that this comprehensive and sensitive hair analysis method can successfully verify a drug after a single exposure in crimes and can be applied in forensic and clinical toxicology laboratories.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cabelo/química , Espectrometria de Massas/métodos , Delitos Sexuais , Detecção do Abuso de Substâncias/métodos , Tiletamina/química , Zolazepam/química , Animais , Anticonvulsivantes/administração & dosagem , Anticonvulsivantes/química , Feminino , Humanos , Masculino , Ratos , Ratos Long-Evans , Sensibilidade e Especificidade , Tiletamina/administração & dosagem , Zolazepam/administração & dosagem
2.
Biochim Biophys Acta Biomembr ; 1866(3): 184294, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38316379

RESUMO

This study presents a new approach to designing a lithocholic acid functionalized oligomer (OLithocholicAA-X) that can be used as a drug carrier with additional, beneficial activity. Namely, this novel oligomer can incorporate an anti-cancer drug due to the application of an effective backbone as its component (lithocholic acid) alone is known to have anticancer activity. The oligomer was synthesized and characterized in detail by nuclear magnetic resonance, attenuated total reflectance Fourier-transform infrared spectroscopy, ultraviolet-visible spectroscopy, thermal analysis, and mass spectrometry analysis. We selected lipid rafts as potential drug carrier-membrane binding sites. In this respect, we investigated the effects of OLithocholicAA-X on model lipid raft of normal and altered composition, containing an increased amount of cholesterol (Chol) or sphingomyelin (SM), using Langmuir monolayers and liposomes. The surface topography of the studied monolayers was additionally investigated by atomic force microscopy (AFM). The obtained results showed that the investigated oligomer has affinity for a system that mimics a normal lipid raft (SM:Chol 2:1). On the other hand, for systems with an excess of SM or Chol, thermodynamically unfavorable fluidization of the films occurs. Moreover, AFM topographies showed that the amount of SM determines the bioavailability of the oligomer, causing fragmentation of its lattice.


Assuntos
Lipossomos , Ácido Litocólico , Ácido Litocólico/análise , Ácido Litocólico/metabolismo , Lipossomos/química , Sistemas de Liberação de Medicamentos , Espectroscopia de Ressonância Magnética , Microdomínios da Membrana/química , Esfingomielinas/química , Colesterol/química
3.
Int J Pharm X ; 5: 100161, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36817971

RESUMO

Therapeutic nucleic acids (TNAs) are gaining increasing interest in the treatment of severe diseases including viral infections, inherited disorders, and cancers. However, the efficacy of intracellularly functioning TNAs is also reliant upon their delivery into the cellular environment, as unmodified nucleic acids are unable to cross the cell membrane mainly due to charge repulsion. Here we show that TNAs can be effectively delivered into the cellular environment using engineered nanoscale metal-organic frameworks (nanoMOFs), with the additional ability to tailor which cells receive the therapeutic cargo determined by the functional moieties grafted onto the nanoMOF's surface. This study paves the way to integrate the highly ordered programmable nucleic acids into larger-scale functionalized nanoassemblies.

4.
Front Chem ; 10: 996857, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36324520

RESUMO

The mechanism of estazolam incorporation into hair was investigated by studying the time course of estazolam along single-strand hair after two oral administration of estazolam at 28 days interval. Estazolam in single hair segments 0.4 mm in length was verified and quantified by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). The distributions of estazolam within a strand of hair (collected at 12 h, 28 days, and 56 days post-administration) were visualized by micro-segmental analysis. The highest estazolam concentration (1.5-9.9 pg/mm) was detected in the hair bulb region (S1), and it then decreased through the hair shaft to the distal end, with a small fluctuation (0.3-3 pg/mm) near the junction of the hair roots and shafts (S4-S7) 12 h after drug intake. These findings suggested that the incorporation of estazolam occurred in two regions, mainly in the hair bulb and to a lesser extent in the upper dermis zone. Models using internal temporal markers (TIMs) and temporal intervals (TIs) were constructed to estimate the day of estazolam ingestion. The estimation accuracy was within an average error of 1.7 mm and 3.0 mm between the calculated and actual positions, based on the TIMs and TIs 56 days after estazolam intake. These findings can help in further elucidation of the drug incorporation mechanism, which is crucial for interpreting hair analysis results used to reveal individual drug-use history.

5.
Forensic Sci Int ; 325: 110881, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34237583

RESUMO

In order to obtain fundamental information on the disposition of hypnotics into hair after a single oral dose the quantitative hair analysis of triazolam (TZ), etizolam (EZ), flunitrazepam (FNZ), nitrazepam (NZ) and zolpidem (ZP) have been performed using a validated LC-MS/MS procedure. Hair specimens (straight, black) were collected from three subjects about one month and three months after a single 0.25 mg dose of TZ, 1 mg of EZ, 2 mg of FNZ, 5 mg of NZ and 10 mg of ZP tartrate. The subjects ingested just one out of five different hypnotics on each day, each of five days in turn. All ingested hypnotics have been detected in hair from each subject both one month and three months after intake, and their concentrations were in the range of 0.023-0.043 pg/hair strand (0.077-0.36 pg/mg) for TZ, 0.11-0.63 pg/hair strand (0.44-5.2 pg/mg) for EZ, 0.14-2.6 pg/hair strand (0.56-22 pg/mg) for FNZ, 0.33-1.7 pg/hair strand (1.3-17 pg/mg) for NZ and 20-40 pg/hair strand (120-270 pg/mg) for ZP. For FNZ and NZ, not only the parent drugs but also their metabolites, 7-amino-FNZ and 7-amino-NZ, were detected in the range of 2.3-9.2 pg/hair strand (9.2-82 pg/mg) and 2.4-9.1 pg/hair strand (8.0-55 pg/mg), respectively. The calculated incorporation ratios into hair against the dose were found to exhibit similarity between the four benzodiazepines. This finding suggests the ability to apply these quantitative data to approximately estimating the amounts of other benzodiazepines, which have similar chemical structures, in hair although it should be noted that the amounts of drugs in hair varies considerably depending on the hair color. On the other hand, the incorporation ratio of ZP showed 15-29 times higher than that of TZ, indicating that lipophilic ZP was more likely to incorporate into hair than benzodiazepines. In addition, the application of the present data to a drug-facilitated sexual assault was shown.


Assuntos
Cabelo/química , Hipnóticos e Sedativos/análise , Adulto , Povo Asiático , Cromatografia Líquida , Crime , Diazepam/administração & dosagem , Diazepam/análogos & derivados , Diazepam/análise , Feminino , Flunitrazepam/administração & dosagem , Flunitrazepam/análise , Toxicologia Forense , Humanos , Hipnóticos e Sedativos/administração & dosagem , Masculino , Espectrometria de Massas , Nitrazepam/administração & dosagem , Nitrazepam/análise , Detecção do Abuso de Substâncias , Triazolam/administração & dosagem , Triazolam/análise , Zolpidem/administração & dosagem , Zolpidem/análise
6.
Forensic Sci Int ; 301: 67-75, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31129374

RESUMO

In order to investigate the influence of pigmentation on the incorporation of drugs into hair, time-course changes in drug distribution along non-pigmented (white) hairs as well as pigmented (black) hairs plucked from the same subject was observed following single administrations of two basic drugs with different properties, zolpidem and methoxyphenamine. These drugs in 1-mm sections of single hair specimens were each determined by a liquid chromatography-tandem mass spectrometric procedure. During the early stage (12-36 h) after intake, for black hairs, both drugs were detected over the entire area of hair root (4-5 mm in length), in which notable concentration of these drugs in the hair bulb (0-1-mm segment from the bottom of hair root, Region 1) and lower concentrations in the upper dermis zone (1-2-mm to 3-4-mm or to 4-5-mm segments, Region 2) were commonly observed. Meanwhile, for white hairs, high drug concentrations in Region 1 as detected in black hairs were not observed although only small amounts of these drugs were detected over Region 2. Subsequent time-course changes in the concentration of drugs in hair demonstrated that the drugs once incorporated into white hair via Region 2 decreased gradually over the period from 24 h to 35 days after intake, but those of black hairs remained almost unchanged. These findings revealed here suggest that hair pigments have two important roles in the distribution of drugs: (1) incorporation of drugs into hair via Region 1, and (2) retention of already incorporated drugs in the hair tissue. These findings would be useful for discussing individual drug-use history based on hair analysis in the forensic fields.


Assuntos
Cor de Cabelo , Cabelo/química , Metanfetamina/análogos & derivados , Zolpidem/análise , Cromatografia Líquida , Toxicologia Forense , Humanos , Hipnóticos e Sedativos/análise , Masculino , Metanfetamina/análise , Pessoa de Meia-Idade , Entorpecentes/análise , Detecção do Abuso de Substâncias/métodos , Espectrometria de Massas em Tandem , Fatores de Tempo
7.
Yakugaku Zasshi ; 139(5): 705-713, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31061339

RESUMO

Hair testing for drugs has been used extensively in the field of forensics since the 1990s as a means of obtaining firm evidence of drug ingestion. In addition to its longer detection windows, hair is the only specimen that can provide chronological information on individual drug use. Illicit drugs and hypnotics account for the majority of substances involved in crimes; they are usually analyzed to prove an addictive use or an exposure to drugs in drug-facilitated crimes. The mechanism of drug incorporation into hair has been intensively investigated to properly interpret the results of hair analysis. However, the exact mechanism remains under much discussion, despite the growing application of hair tests. Recently, the authors have applied matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) imaging and sectional hair analysis of 1-mm segments using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for single-strand hair, to investigate the incorporation pathways of drugs into hair. Time-course changes in drug distribution along single-strand hair suggest that the incorporation of drugs occurs in two regions of the hair root, the hair bulb and the upper part of hair root, and suggest that incorporation from the hair bulb continues for about 2 weeks. Distribution profiles of different drugs in hair additionally revealed that the main incorporation pathway varies (i.e., via the hair bulb or the upper part of hair root) depending on the properties of the drug/metabolite. These findings should be taken into account upon discussing individual drug-use history based on the results of hair analysis.


Assuntos
Cromatografia Líquida/métodos , Medicina Legal/métodos , Cabelo/química , Cabelo/metabolismo , Hipnóticos e Sedativos/análise , Hipnóticos e Sedativos/metabolismo , Drogas Ilícitas/análise , Drogas Ilícitas/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Detecção do Abuso de Substâncias/métodos , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Espectrometria de Massas em Tandem/métodos , Crime , Humanos , Fatores de Tempo
8.
Mater Sci Eng C Mater Biol Appl ; 91: 734-742, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30033308

RESUMO

MCM-48 is crystalline, mesoporous silicate used in catalysis and for adsorption various molecules to create useful materials for chemistry, pharmacy and medicine. In this work, the MCM-48 silicate has been coated with nanohydroxyapatite (HA) to design a new drug delivery system. The MCM-48/hydroxyapatite composite was synthesized using a new method involving precipitation of HA onto the earlier prepared MCM-48. The method gives an interesting mesoporous material capable of adsorbing drugs on its external surface and on the internal surface in mesopores. This was shown using ibuprofen (Ibu). The MCM-48/HA composites and MCM-48/HA/Ibu conjugates have been thoroughly characterized using various physicochemical methods. It was concluded that the MCM-48/HA composite offers a significant potential for controlled drug delivery systems involving small API molecules.


Assuntos
Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Durapatita/química , Ibuprofeno/farmacologia , Dióxido de Silício/química , Adsorção , Espectroscopia de Ressonância Magnética , Nitrogênio/química , Porosidade , Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
9.
Colloids Surf B Biointerfaces ; 161: 578-587, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29149763

RESUMO

Despite extensive studies of the effects of herbal-derived small molecules in the biopharmaceutical and biomedical sciences, their low solubility and stability remain a challenge. Here we focus on baicalein, a small molecule showing potential against neurodegenerative diseases such as Parkinson's and Alzheimer's. However, therapeutic usage in vivo is challenged by low solubility and stability. To address this we have applied neutrally-charged nanoliposome (NLP) as carrier for baicalein. Baicalein was incorporated into NLP to form NLP-Ba at molar baicalain:lipid ratios of up to 1:3, giving a drug entrapment efficiency of 96.71%, slow release of approximately 22% after a week and increased baicalein stability up to 27%. Ascorbic acid increased baicalein's stability further, particularly when incorporated in NLP where baicalein stability intensified by 53% in NLP-Ba. Moreover, NLP-Ba did not show significant cytotoxic effects against neurons; rather, showed considerable protective effect against reactive oxygen species. In addition, NLP promoted internalization of baicalein into cells, showing good biocompatibility. We conclude that NLP-Ba can enhance baicalein's therapeutic potential in neurodegenerative diseases.


Assuntos
Flavanonas/química , Lipossomos/química , Nanoestruturas/química , Neurônios/metabolismo , Animais , Antioxidantes/química , Antioxidantes/farmacocinética , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Flavanonas/farmacocinética , Flavanonas/farmacologia , Humanos , Lipossomos/ultraestrutura , Microscopia Eletrônica de Transmissão , Nanoestruturas/ultraestrutura , Neurônios/efeitos dos fármacos , Células PC12 , Ratos , Espécies Reativas de Oxigênio/metabolismo
10.
Curr Pharm Des ; 23(36): 5468-5479, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28677498

RESUMO

BACKGROUND: The analysis of nails as a keratinized matrix to detect drugs or illicit substances has been increasingly used in forensic and clinical toxicology as a complementary test, especially for the specific characteristics of stably accumulating substances for long periods of time. This allows a retrospective investigation of chronic drug abuse, monitoring continuous drug or pharmaceutical use, reveal in utero drug exposure or environmental exposures. METHODS: We herein review the recent literature investigating drug incorporation mechanisms and drug detection in nails for forensic toxicological purposes. RESULTS: Mechanisms of drug incorporation have not yet been fully elucidated. However, some research has lately contributed to a better understanding of how substances are incorporated into nails, suggesting three potential mechanisms of drug incorporation: contamination from sweat, incorporation from nail bed and incorporation from germinal matrix. In addition, numerous methods dealing with the determination of drugs of abuse, medications and alcohol biomarkers in nails have been reported in studies over the years. The latter methods could find application in clinical and forensic toxicology. CONCLUSION: The studies herein reviewed point out how important it is to standardize and harmonize the methodologies (either pre-analytical or analytical) for nails analysis and the optimization of sampling as well as the development of proficiency testing programs and the determination of cut-off values.


Assuntos
Toxicologia Forense/métodos , Unhas/química , Preparações Farmacêuticas/análise , Detecção do Abuso de Substâncias/métodos , Autopsia/métodos , Autopsia/tendências , Toxicologia Forense/tendências , Humanos , Unhas/patologia , Detecção do Abuso de Substâncias/tendências
11.
Carbohydr Polym ; 174: 1087-1094, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28821031

RESUMO

Surface-deacetylated chitin nanofibers (SDACNFs) reinforced with a sulfobutyl ether ß-cyclodextrin (SBE-ß-CD) (NFs-CDs) gel were developed to obtain a controlled release carrier of prednisolone (PD) for the treatment of colitis. PD was released slowly from the gel at both pH 1.2 and 6.8. The in vitro slow release of PD from the NFs-CDs gel was reflected in the in vivo absorption of the drug after oral administration to rats. These results suggest that a simple gel composed of a mixture of SDACNFs and SBE-ß-CD has the potential for use in the controlled release of PD. We also evaluated the therapeutic effects of the NFs-CDs gel containing PD on dextran sulfate sodium (DSS)-induced colitis model mice. The administration of the NFs-CDs gel at intervals of 3days from the beginning of the DSS treatment resulted in a significant improvement, not only in colitis symptoms but also histopathological changes in colon tissue. In addition, the therapeutic effects of the NFs-CDs gel on colitis can be attributed to decreased levels of neutrophil infiltration and the development of oxidative stress. These efficacy profiles of the NFs-CDs gel containing PD suggest that it has the potential for use in the treatment of, not only colitis, but also a variety of other disorders associated with inflammation and oxidative injuries.


Assuntos
Quitina/química , Doenças Inflamatórias Intestinais/tratamento farmacológico , Nanofibras , Prednisolona/administração & dosagem , beta-Ciclodextrinas/química , Animais , Colite/induzido quimicamente , Colite/tratamento farmacológico , Preparações de Ação Retardada , Sulfato de Dextrana , Géis , Masculino , Camundongos , Camundongos Endogâmicos ICR , Ratos , Ratos Wistar , Solubilidade
12.
Curr Pharm Des ; 2017 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-29141534

RESUMO

BACKGROUND: Solid lipid nanoparticles (SLN) and the next generation of nanostructured lipid carriers (NLC) seem to be a very promising alternative to other colloidal carriers such as liposomes, microemulsions, and polymeric nanoparticles. These combine the advantages of the cited nanocarriers and can improve the dissolution rate in biological fluids, increase the drug absorption, improve the tissue distribution in the target organ, enhance the drug bioavailability and ensure controlled drug release. SLN and NLC can ensure higher drug stability in the harsh environment, cover the bitter taste of the drug, and reduce the first-pass-effect after oral administration. However, these carriers suffer from some disadvantages such as low drug loading capacity, drug expulsion, and unpredictable gelation tendency. METHODS: This article aims to provide detail information about the process of complex characterization of SLN and NLC to produce an effective, quality and safe colloidal DDS with desired properties, based on the literature published in the period from 2000 to 2017. RESULTS: Characterization techniques in terms of size and particle size distribution; surface morphology, functionalization, and zeta potential; structure, depending on the degree of crystallinity, lipid modification, drug incorporation and loading capacity; drug release; co-existence of other nano- and microstructures; and toxicity assessment according to the process of production, lipids and surfactants used and route of administration are discussed in the article. CONCLUSION: The precise characterization of lipid nanocarriers as drug delivery systems ensures guarantees for the quality of the product as an effective and safe form. The typical composition of SLN and NLC requires a comprehensive approach of characterization and in-depth analysis of the results to perform a drug delivery system with desired properties.

13.
Int J Pharm ; 511(2): 1080-7, 2016 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-27521704

RESUMO

A freeze-dried gel composed of surface-deacetylated chitin nanofibers (SDACNFs), reinforced with an anionic cyclodextrin, sulfobutyl ether ß-cyclodextrin (SBE-ß-CD) was evaluated for treating wounds in a rat model, and the results were compared with a SDACNFs gel without SBE-ß-CD. The incorporation of prednisolone (PD), a poorly water-soluble drug, in both types of gels and its release from the gels were also compared. In both cases, wound areas were decreased and their effect was higher than that of commercially available wound dressings. The rate of release of PD from the freeze-dried SDACNFs/SBE-ß-CD was much faster than that form SDACNFs alone without SBE-ß-CD, due to fact that the PD is more soluble in the amorphous SBE-ß-CD complex compared to the other preparations. The findings indicate that the freeze-dried SDACNFs/SBE-ß-CD gel would be beneficial as a new biomaterial for the treatment of wounds and for preparing homogeneous high-content gels that contain poorly water-soluble drugs.


Assuntos
Bandagens , Materiais Biocompatíveis/química , Quitina/química , Nanofibras/química , Cicatrização/efeitos dos fármacos , beta-Ciclodextrinas/química , Animais , Materiais Biocompatíveis/administração & dosagem , Quitina/administração & dosagem , Liberação Controlada de Fármacos , Feminino , Liofilização/métodos , Nanofibras/administração & dosagem , Ratos , Ratos Wistar , beta-Ciclodextrinas/administração & dosagem
14.
Int J Pharm ; 492(1-2): 191-8, 2015 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-26163764

RESUMO

The present paper reported amino group functionalized anionic surfactant templated mesoporous silica (Amino-AMS) for loading and release of poorly water-soluble drug indomethacin (IMC) and carboxyl group functionalized cationic surfactant templated mesoporous silica (Carboxyl-CMS) for loading and release of poorly water-soluble drug famotidine (FMT). Herein, Amino-AMS and Carboxyl-CMS were facilely synthesized using co-condensation method through two types of silane coupling agent. Amino-AMS was spherical nanoparticles, and Carboxyl-CMS was well-formed spherical nanosphere with a thin layer presented at the edge. Drug loading capacity was obviously enhanced when using Amino-AMS and Carboxyl-CMS as drug carriers due to the stronger hydrogen bonding force formed between surface modified carrier and drug. Amino-AMS and Carboxyl-CMS had the ability to transform crystalline state of loaded drug from crystalline phase to amorphous phase. Therefore, IMC loaded Amino-AMS presented obviously faster release than IMC because amorphous phase of IMC favored its dissolution. The application of asymmetric membrane capsule delayed FMT release significantly, and Carboxyl-CMS favored sustained release of FMT due to its long mesoporous channels and strong interaction formed between its carboxyl group and amino group of FMT.


Assuntos
Portadores de Fármacos/química , Silanos/química , Dióxido de Silício/química , Tensoativos/química , Liberação Controlada de Fármacos , Famotidina/química , Indometacina/química , Porosidade , Propilaminas , Solubilidade , Água/química
15.
Nanomedicine (Lond) ; 10(21): 3213-30, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26548350

RESUMO

Incorporation of nanotechnology in the field of drug delivery has created exciting opportunities for the purposeful design of nanocarriers with potentials such as targeted delivery or controlled release of the incorporated cargo, improvement of bioavailability and reduction of therapeutic side-effects. Prior to in vivo administration, nanocarriers should undergo a set of in vitro evaluation procedures to ensure their stability, safety, conformity and ability to fulfill the desired mission. In this paper, current issues with in vitro evaluation techniques used for nanocarrier characterization (assessment of particle size, surface charge, drug release and toxicity) will be discussed. Furthermore, sufficiency of in vitro evaluation procedures for the prediction of in vivo scenarios and the necessary considerations to improve the correlation between the two settings will be debated.


Assuntos
Portadores de Fármacos , Nanopartículas , Técnicas In Vitro , Microscopia Eletrônica de Varredura
16.
J Pharm Sci ; 103(2): 697-705, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24375427

RESUMO

The effect of polymorphism of glycerol monostearate (GMS) on drug incorporation and release from lipid matrix particles (LMPs) was investigated using fenofibrate as a model drug. X-ray powder diffraction and differential scanning calorimetry were used to study the polymorphism change of GMS and the drug incorporation in GMS matrix. When medium-chain triglycerides (MCT) was absent, melted GMS was frozen to α-form of GMS with drug molecularly dispersed, whereas ß-form of GMS was formed with part of drug crystallized out when the ratio of GMS/MCT in the lipid matrix was 2:1 (w/w). For LMP composed of GMS/MCT (2:1, w/w) prepared, GMS was in α-form when the particles were in nanometer range, whereas GMS was in ß-form when lipid particles were in micrometer range. The model drug was molecularly dispread in α-form lipid nanoparticles, whereas part of drug was expulsed out from microparticles because of the denser crystalline packing than α-form of GMS, and caused a faster drug release from lipid microparticles than that from nanoparticles. During the storage, the transformation of GMS from α-form into the more stable ß-form promoted drug expulsion and caused drug precipitation. In conclusion, the polymorphism of GMS is an important factor determining particle stability, drug incorporation, and the release of the drug from LMP. Critical attention should be paid on the investigation as well as control of the lipid polymorphism when formulating lipid-based matrix particles.


Assuntos
Fenofibrato/administração & dosagem , Glicerol/análogos & derivados , Hipolipemiantes/administração & dosagem , Nanopartículas/química , Estearatos/química , Varredura Diferencial de Calorimetria , Cristalização , Desenho de Fármacos , Estabilidade de Medicamentos , Fenofibrato/química , Glicerol/química , Hipolipemiantes/química , Indicadores e Reagentes , Microscopia Eletrônica de Transmissão , Monoglicerídeos , Tamanho da Partícula , Solubilidade , Difração de Raios X
17.
Int J Pharm ; 477(1-2): 623-30, 2014 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-25445973

RESUMO

Injectable thermoreversible chitosan (CS)/ß-glycerophosphate (ß-GP) hydrogels were developed for prolonged localized delivery of cisplatin (Cis). The effects of formulation variables on the thermoreversible hydrogels preparation as well as the impact of drug incorporation method on Cis release were studied. Antitumor activity of Cis CS/ß-GP thermoreversible hydrogels were evaluated against HCT-116 human colorectal cancer cells and MCF-7 human breast cancer cells. Incorporation of Cis to CS solution adjusted at pH 6.2 prior to hydrogel preparation deemed necessary to achieve a sustained release up to 4 days. Cis loaded CS/ß-GP thermoreversible hydrogels showed enhanced antitumor activity with about 1.2 fold and 2.05 fold that of Cis solution against HCT-116 cancer cells and MCF-7 cancer cells respectively. The obtained enhanced antitumor activity elected this delivery system for further in vivo and toxicological investigations.


Assuntos
Antineoplásicos/administração & dosagem , Quitosana/química , Cisplatino/administração & dosagem , Materiais Revestidos Biocompatíveis/química , Portadores de Fármacos/química , Glicerofosfatos/química , Hidrogéis/química , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Células HCT116 , Humanos , Concentração de Íons de Hidrogênio , Células MCF-7 , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Temperatura
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