RESUMEN
Multi-injection pharmaceutical products such as insulin must be formulated to prevent aggregation and microbial contamination. Small-molecule preservatives and nonionic surfactants such as poloxamer 188 (P188) are thus often employed in protein drug formulations. However, mixtures of preservatives and surfactants can induce aggregation and even phase separation over time, despite the fact that all components are well dissolvable when used alone in aqueous solution. A systematic study is conducted here to understand the phase behavior and morphological causes of aggregation of P188 in the presence of the preservatives phenol and benzyl alcohol, primarily using small-angle x-ray scattering (SAXS). Based on SAXS results, P188 remains as unimers in solution when below a certain phenol concentration. Upon increasing the phenol concentration, a regime of micelle formation is observed due to the interaction between P188 and phenol. Further increasing the phenol concentration causes mixtures to become turbid and phase-separate over time. The effect of benzyl alcohol on the phase behavior is also investigated.
Asunto(s)
Micelas , Poloxámero , Dispersión del Ángulo Pequeño , Rayos X , Difracción de Rayos X , Tensoactivos , Agua , Conservadores Farmacéuticos , Fenoles , Alcoholes Bencílicos , SolucionesRESUMEN
We aimed to understand the impact of the interplay between bile salts and cyclodextrins on the dissolution-permeation of poorly soluble drug compounds with a moderate-strong binding constant to cyclodextrin. Phase diagrams were prepared on the chosen model compound albendazole in phosphate buffer, fasted state simulated intestinal fluid (FaSSIF), and a modified fed state simulated intestinal fluid (FeSSIFmod) with (2-hydroxypropyl)-beta-cyclodextrin (HP-ß-CD) concentrations of up to 10 % (m/m). Then we investigated the dissolution/permeation interplay of albendazole dissolved/suspended in the different media through a biomimetic barrier on a 96-well in vitro model. The apparent solubility of albendazole was enhanced by HP-ß-CD and FaSSIF/FeSSIFmod separately. However, when albendazole was dissolved in HP-ß-CD and biomimetic media together, the solubility was significantly lower than the predicted additive solubility from the solubilizing effects. It is postulated that this is due to the sodium taurocholate from the biomimetic media displacing albendazole from the hydrophobic cavity of HP-ß-CD. In the permeation experiments, the highest permeation was observed at cyclodextrin concentrations able to solubilize close to the total dose of albendazole without a major surplus of solubilization capacity. Furthermore, an over-proportional permeation enhancement was observed when both, cyclodextrin and biomimetic media were present. These results indicate that the interplay between bile salts and cyclodextrins can enhance the free (molecularly dissolved) fraction of drug in solution to a greater extent than could be obtained with one of the solubilizing components alone. In conclusion, at carefully selected cyclodextrin-concentrations in combination with biomimetic media, obviously, a transient supersaturation is induced, which is made responsible for the observed major permeation enhancement.
Asunto(s)
Ciclodextrinas , 2-Hidroxipropil-beta-Ciclodextrina , Albendazol/química , Ácidos y Sales Biliares , Disponibilidad Biológica , Ciclodextrinas/química , SolubilidadRESUMEN
Voriconazole (VRC) is a broad spectrum, second generation triazole antifungal. The main use of VRC is via the oral and intravenous route. The study aimed to formulate VRC into ternary micellar systems (TMSs) for the topical treatment of ocular mycosis. TMSs were successfully prepared by water addition/solvent evaporation method, applying a 3-factor D-optimal design. The numerical optimization process suggested an optimal formula (OTMS) composed of total Pluronics to drug weight ratio of 22.89: 1, 1:1 weight ratio of Pluronic® P123 and F68, and 2% w/v of Labrasol. OTMS had high solubilization efficiency of 98.0%, small micellar size of 21.8 nm and suitable zeta potential and polydispersity index values of -9.0 mV and 0.261, respectively. OTMS exhibited acceptable stability for 3 months. Transmission electron microscopy demonstrated the spherical morphology of micelles. OTMS was expected to cause no ocular irritation or blurring in vision as reflected by pH and refractive index measurements. The histopathological study revealed the safety of OTMS for ocular use. The fungal susceptibility testing using Candida albicans demonstrated the superiority of OTMS to VRC suspension, with greater and more durable growth inhibition. Therefore, ocular application of optimized VRC-loaded TMSs can be a promising treatment for ocular mycosis.
Asunto(s)
Infecciones Fúngicas del Ojo , Micelas , Antifúngicos/uso terapéutico , Portadores de Fármacos/uso terapéutico , Sistemas de Liberación de Medicamentos , Infecciones Fúngicas del Ojo/tratamiento farmacológico , Humanos , Tamaño de la Partícula , Voriconazol/uso terapéuticoRESUMEN
Owing to the discovery of a less soluble crystalline form (form 2) of cyclosporine (CsA), risks in solubility and physical stability of these formulations need to be revisited. This work focused on understanding the solubility behavior of various CsA forms in different media, including water, castor oil, and selected cosolvent micellar systems. In water, form 2 was approximately 8-9 times less soluble than form 1 (aka. tetragonal dihydrate). In neat nonaqueous solvent, for example, castor oil, form 3 (aka. orthorhombic hydrate) was found to have the lowest solubility and therefore the most stable form. In addition, the solubility-temperature relationship of CsA is complex and solvent-dependent. In aqueous vehicles, retrograde temperature dependence of solubility was observed in aqueous vehicles, that is, the solubility of CsA decreased with temperature, which was attributed to the effect of temperature on the strength of hydrogen bonding interactions; conversely, the solubility of CsA increased with temperature in nonaqueous solvents. In addition, the solubility of these CsA forms was very sensitive to temperature. Temperature-dependent form transformation was also observed in the media studied, with faster form conversion occurring at elevated temperatures. These studies provided key information to support the risk assessment for topical ophthalmic formulation development of CsA.
Asunto(s)
Ciclosporina/química , Soluciones Oftálmicas/química , Solubilidad/efectos de los fármacos , Aceite de Ricino/química , Química Farmacéutica/métodos , Excipientes/química , Ojo/efectos de los fármacos , Enlace de Hidrógeno , Micelas , Medición de Riesgo , Solventes/química , Temperatura , Agua/químicaRESUMEN
Magnetic nanocarriers are useful in targeted cancer therapy. Dasatinib (DAS)-loaded magnetic micelles were prepared for magnetically guided drug delivery. The magnetic nanoplatform is composed of hydrophobic oleic acid-coated magnetite (Fe3O4) core along with DAS encapsulated in amphiphilic zein-lactoferrin self-assembled polymeric micelles. Transmission electron microscope analysis manifested formation of these magnetic micelles with a mean diameter of about 100 nm. In addition, drug-loaded magnetic micelles displayed a saturation magnetization of about 10.01 emu.g-1 with a superparamagnetic property. They also showed good in vitro serum stability and hemocompatibility accompanied with a sustained release of DAS in acidic pH. More importantly, they exhibited 1.35-fold increase in their in vitro cytotoxicity against triple-negative human breast cancer cell line (MDA-MB-231) using an external magnetic field compared to drug-loaded magnetic micelles in the absence of a magnetic field. Enhanced inhibition of p-c-Src protein expression level and in vitro cellular migration under the effect of magnetic field was noted owing to the dual-targeting strategy offered by the presence of a magnetic sensitive core, as well as the active targeting property of lactoferrin corona. Taken all together, these results suggest that DAS-loaded magnetic micelles possess a great potential for targeted therapy of breast cancer.
Asunto(s)
Dasatinib/química , Dasatinib/farmacología , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Preparaciones de Acción Retardada/química , Preparaciones de Acción Retardada/farmacología , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Lactoferrina/química , Magnetismo/métodos , Micelas , Polímeros/química , Zeína/químicaRESUMEN
An iconic textbook that pharmaceutical scientists encounter in undergraduate courses is "Martin's Physical Pharmacy and Pharmaceutical Sciences." Within the chapter on Colloids, a figure indicates the location of solubilization of molecules within spherical, nonionic surfactant micelles. The surfactant consists of polyethylene glycol (PEG) hydrophilic headgroups and alkane chains for the hydrophobic tail. The figure shows benzene and toluene within the alkane core, salicylic acid (2-hydroxybenzoic acid) at the interface between the core and PEG chains, and then para-hydroxybenzoic acid (4-hydroxybenzoic acid) located between the PEG chains. Molecular dynamics simulations of octaethylene glycol monododecyl ether micelles were performed with a series of probe molecules, including those within the Martin's figure, to determine their solubilization location. Relative placement of molecules within the micelle was correct; however, some specifics were different. In particular, benzene and toluene are excluded from the core, and 4-hydroxybenzoic acid prefers to maintain contact with the core. A series of molecules containing 6 carbon atoms were also studied to determine the effects of cyclization (moves out of core), polar functionalization (anchored to interface), and aromatization (excluded from central core). Molecular dynamics was found to be a useful tool for gaining insight into interactions important in solubilization of molecules.
Asunto(s)
Micelas , Modelos Químicos , Simulación de Dinámica Molecular , Sondas Moleculares/química , Química Farmacéutica , Solubilidad , Tensoactivos/químicaRESUMEN
UNLABELLED: Synthetic cannabinoid WIN55,212-2 (WIN) has shown a promise as an anticancer agent but causes psychoactive side-effects. In the present study, nano-micelles of styrene maleic acid (SMA)-conjugated WIN were synthesized to reduce side-effects and increase drug efficacy. SMA-WIN micelles were characterised and their in vitro cytotoxic effect was compared to that of free WIN against triple-negative breast cancer (MDA-MB-231), hormone receptor-positive breast cancer (MCF-7) and castration-resistant prostate cancer (PC3) cell lines. SMA-WIN micelles were synthesised with a ~15% loading, 132.7 nm average diameter, -0.0388 mV charge, and pH-dependent release rate. A dose-dependent inhibition of cell growth was observed in all three cell lines treated with both free and micellar WIN, with both formulations demonstrating equal cytotoxicity. CONCLUSION: SMA-WIN demonstrated characteristics theorized to improve in vivo drug biodistribution. Potent cytotoxicity was found against breast and prostate cancer cells in vitro, showing promise as a novel treatment against breast and prostate cancer.