Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Environ Sci Technol ; 58(6): 2728-2738, 2024 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-38232385

RESUMEN

Understanding geochemical dissolution in porous materials is crucial, especially in applications such as geological CO2 storage. Accurate estimation of reaction rates enhances predictive modeling in geochemical-flow simulations. Fractured porous media, with distinct transport time scales in fractures and the matrix, raise questions about fracture-matrix interface dissolution rates compared to bulk dissolution rate and the scale-dependency of reaction rate averaging. Our investigation delves into these factors, studying the impact of flow rate and mineralogy on interface dissolution patterns. By injecting carbonated water into carbonate rock samples containing a central channel (mimicking fracture hydrodynamics), our study utilized µCT X-ray imaging at 3.3 µm spatial resolution to estimate the reaction rate and capture the change in pore morphology. Results revealed dissolution rates significantly lower (up to 4 orders of magnitude) than batch experiments. Flow rate notably influenced fracture profiles, causing uneven enlargement at low rates and uniform widening at higher ones. Ankerite presence led to a dissolution-altered layer on the fracture surface, showing high permeability and porosity without greatly affecting the dissolution rate, unlike clay-rich carbonates. This research sheds light on controlling factors influencing dissolution in subsurface environments, critical for accurate modeling in diverse applications.


Asunto(s)
Dióxido de Carbono , Carbonatos , Microtomografía por Rayos X
2.
AAPS PharmSciTech ; 25(6): 142, 2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38898170

RESUMEN

Skin diseases pose challenges in treatment due to the skin's complex structure and protective functions. Topical drug delivery has emerged as a preferred method for treating these conditions, offering localized therapy with minimal systemic side effects. However, the skin's barrier properties frequently limit topical treatments' efficacy by preventing drug penetration into deeper skin layers. In recent years, laser-assisted drug delivery (LADD) has gained attention as a promising strategy to overcome these limitations. LADD involves using lasers to create microchannels in the skin, facilitating the deposition of drugs and enhancing their penetration into the target tissue. Several lasers, such as fractional CO2, have been tested to see how well they work at delivering drugs. Despite the promising outcomes demonstrated in preclinical and clinical studies, several challenges persist in implementing LADD, including limited penetration depth, potential tissue damage, and the cost of LADD systems. Furthermore, selecting appropriate laser parameters and drug formulations is crucial to ensuring optimal therapeutic outcomes. Nevertheless, LADD holds significant potential for improving treatment efficacy for various skin conditions, including skin cancers, scars, and dermatological disorders. Future research efforts should focus on optimizing LADD techniques, addressing safety concerns, and exploring novel drug formulations to maximize the therapeutic benefits of this innovative approach. With continued advancements in laser technology and pharmaceutical science, LADD has the potential to revolutionize the field of dermatology and enhance patient care.


Asunto(s)
Administración Cutánea , Sistemas de Liberación de Medicamentos , Rayos Láser , Absorción Cutánea , Enfermedades de la Piel , Piel , Humanos , Sistemas de Liberación de Medicamentos/métodos , Piel/metabolismo , Absorción Cutánea/fisiología , Absorción Cutánea/efectos de los fármacos , Enfermedades de la Piel/tratamiento farmacológico , Animales
3.
Dermatol Ther ; 33(6): e14467, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33112463

RESUMEN

FDA-approved drugs for the most common type of hair loss, androgenetic alopecia (AGA), present many side effects and disadvantages. However, herbal compounds are characterized by patient compliance, fewer side effects, and several mechanisms of action. The present study set to evaluate the effectiveness and safety of the topical herbal solution and to compare it with 5% minoxidil in men with AGA. A randomized, double-blind controlled trial was conducted from 28 November 2018 to 2 September 2019, in Sina Hospital, Tabriz, Iran. 24 healthy males (mean [SD] age 33.04 [5.81]) with mild to moderate AGA were selected from 44 volunteer participants. Participants were randomly assigned (1:1) into two groups. They received 1 ml of topical solutions at morning and evening intervals for 9 months. Primary outcomes consisted of measured hair diameters at baseline and repeated at weeks 12, 24, and 36. Furthermore, hair density was measured at baseline and week 36. The MTS + THS group was significantly superior to the MTS group after 36 weeks of therapy in the hair diameter improvement. At week 36, the mean hair diameter of the MTS + THS group significantly increased compared to the MTS group (P = .001). Hair density increased in both groups; however, only in the MTS + THS group, it was significant (P < .05). The findings established that the topical herbal solution has significant influence on patients with AGA and improvement of their quality of life. This solution can be considered a significant step towards the prevention and treatment of AGA. clinicaltrials.gov Identifier: NCT03753113.


Asunto(s)
Alopecia , Medicina de Hierbas , Minoxidil , Calidad de Vida , Administración Tópica , Adulto , Alopecia/diagnóstico , Alopecia/tratamiento farmacológico , Método Doble Ciego , Humanos , Irán , Masculino , Minoxidil/uso terapéutico , Resultado del Tratamiento
4.
Pak J Pharm Sci ; 32(5): 1979-1986, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31813861

RESUMEN

The aim of this study was to design and develop controlled porosity osmotic pumps containing glibenclamide (as an insoluble agent) coated with nano-scale pore formers. Solubility enhancement methods including co-grinding with an anionic surfactant and pH adjustment in core formulation were employed and the prepared cores were coated with nano-suspension coating method. The prepared nano-porous osmotic pump (CPOP) system assessed by comparative parameters including D24h (cumulative release percentage after 24h), tL (lag time of the drug release from device), drug release rate from device and RSQzero. Solubility studies of glibenclamide co-ground with an anionic surfactant showed that by increasing the concentration of SLS to 83.33% (ratio of drug: SLS 1:5) in the presence of calcium carbonate, the solubility of glibenclamide was enhanced remarkably. Release study also displayed enhanced D24h and improved kinetic related parameter (RSQ zero) by increasing SLS and calcium carbonate in the core formulation via nano-porous CPOPs. It can be concluded that by employing both co-grinding technology and pH adjustment method in core formulation of glibenclamidenano-suspension coated CPOPs, enhanced D24h, drug release rate and improved kinetic related parameter (RSQ zero)) was achieved.


Asunto(s)
Preparaciones de Acción Retardada/química , Gliburida/química , Nanopartículas/química , Ósmosis/efectos de los fármacos , Agua/química , Carbonato de Calcio/química , Química Farmacéutica/métodos , Sistemas de Liberación de Medicamentos/métodos , Concentración de Iones de Hidrógeno , Cinética , Porosidad , Solubilidad , Tensoactivos/química , Suspensiones/química
5.
Drug Dev Ind Pharm ; 41(10): 1640-6, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25382163

RESUMEN

CONTEXT: Cellulite refers to dimpled appearance of the skin, usually located in the thighs and buttocks regions of most adult women. OBJECTIVE: The aim of this study was to formulate topically used caffeine-loaded solid lipid nanoparticle (SLN) for the treatment of cellulite. METHODS: SLNs were prepared by hot homogenization technique using Precirol® as lipid phase. The physical characterization and stability studies of SLNs as well as in vitro skin permeation and histological studies in rat skin were conducted. RESULTS: The mean particle size, encapsulation efficiency and loading efficiency percentages for optimized SLN formulation were 94 nm, 86 and 28%, respectively. In vitro drug release demonstrated that caffeine-loaded SLN incorporated into carbopol made hydrogel (caffeine-SLN-hydrogel) exhibited a sustained drug release compared to the caffeine hydrogel over 24 h. Caffeine-loaded SLNs showed a good stability during 12 months of storage at room temperature. The DSC and XRD results showed that caffeine was dispersed in SLN in an amorphous state. In vitro permeation studies illustrated higher drug accumulation in the skin with caffeine-SLN-hydrogel compared to caffeine hydrogel. The flux value of caffeine through rat skin in caffeine-SLN-hydrogel was 3.3 times less than caffeine hydrogel, representing lower systemic absorption. In contrast with caffeine hydrogel, the histological studies showed the complete lysis of adipocytes by administration of caffeine-SLN-hydrogel in the deeper skin layers. CONCLUSION: Results of this study indicated that SLNs are promising carrier for improvement of caffeine efficiency in the treatment of cellulite following topical application on the skin.


Asunto(s)
Tejido Adiposo/efectos de los fármacos , Cafeína/administración & dosificación , Portadores de Fármacos/administración & dosificación , Hidrogeles/química , Nanopartículas/química , Acrilatos/química , Administración Cutánea , Animales , Cromatografía Líquida de Alta Presión , Preparaciones de Acción Retardada , Diglicéridos/química , Liberación de Fármacos , Femenino , Tamaño de la Partícula , Ratas , Ratas Wistar , Absorción Cutánea , Tecnología Farmacéutica , Difracción de Rayos X
6.
Pharm Dev Technol ; 19(4): 507-12, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23763379

RESUMEN

The major problem associated with conventional drug delivery systems is unpredictable plasma concentrations. The aim of this study was to design a controlled porosity osmotic pump (CPOP) of diltiazem hydrochloride to deliver the drug in a controlled manner. CPOP tablets were prepared by incorporation of drug in the core and subsequent coating with cellulose acetate as semi-permeable membrane. Non-ionic surfactants were applied as pore-formers as well. The effect of pore-formers concentration on the in vitro release of diltiazem was also studied. The formulations were compared based on four comparative parameters, namely, total drug released after 24 h (D24 h), lag-time (tL), squared correlation coefficient of zero order equation (RSQzero) and mean percent deviation from zero order kinetic (MPDzero). Results of scanning electron microscopy studies exhibited formation of pores in the membrane from where the drug release occurred. It was revealed that drug release rate was directly proportional to the concentration of the pore-formers. The value of D24 h in the formulations containing Tween 80 (10%) and Brij 35 (5%) were found to be more than 94.9%, and drug release followed zero order kinetic (RSQzero > 0.99 and MPDzero < 8%) with acceptable tL (lower than 1 h).


Asunto(s)
Preparaciones de Acción Retardada/síntesis química , Diltiazem/química , Tensoactivos/química , Celulosa/análogos & derivados , Celulosa/química , Química Farmacéutica , Sistemas de Liberación de Medicamentos/métodos , Cinética , Ósmosis , Polietilenglicoles/química , Polisorbatos/química , Porosidad , Comprimidos/química
7.
J Cosmet Dermatol ; 23(6): 2145-2155, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38415395

RESUMEN

BACKGROUND: The emulgel, a novel drug delivery system, merges emulsion and gel, offering advantages like enhanced stability, precise control over drug release kinetics, and increased drug absorption compared to emulsions alone. Kojic acid (KA) demonstrates potent inhibition of the tyrosinase enzyme, a crucial player in the melanin synthesis pathway. AIMS: The main objective of this experimental study is to formulate KA within an emulgel framework and assess its stability under various environmental conditions. METHODS: One percent of KA emulgel and 1% simple gel, serving as the control product, were supplemented with varying concentrations of sodium metabisulfite (SMBS) for its antioxidant properties. The formulations were segregated into four groups and subjected to diverse maintenance and stress conditions over a three-month period. Monthly evaluations of physicochemical alterations were conducted, initially employing digital photography, followed by the extraction of KA and subsequent quantification of its concentration through high performance liquid chromatography (HPLC). RESULTS: The best formulations for retaining KA among the prepared ones were the 0.25% SMBS KA emulgel and the 0.1% SMBS KA simple gel, capable of retaining 86% and 76% of the initial KA content under stress conditions, respectively (p < 0.0001). CONCLUSIONS: Regarding to this study, ideal storage condition for KA emulgel and simple gel is in the refrigerator temperatures. Moreover, optimal SMBS concentrations for stability enhancement are 0.25% for emulgel and 0.1% for the simple gel. A significant statistical difference was observed between refrigerated emulgel and simple gel in the retention of KA in the presence of optimum concentration of antioxidants (p < 0.0001).


Asunto(s)
Estabilidad de Medicamentos , Emulsiones , Geles , Pironas , Pironas/administración & dosificación , Pironas/farmacocinética , Pironas/farmacología , Emulsiones/química , Antioxidantes/administración & dosificación , Antioxidantes/farmacología , Hiperpigmentación/tratamiento farmacológico , Humanos , Almacenaje de Medicamentos , Sistemas de Liberación de Medicamentos/métodos , Administración Cutánea , Composición de Medicamentos/métodos , Sulfitos/química , Sulfitos/administración & dosificación , Preparaciones para Aclaramiento de la Piel/administración & dosificación , Preparaciones para Aclaramiento de la Piel/química , Preparaciones para Aclaramiento de la Piel/farmacología
8.
Bioimpacts ; 13(2): 109-121, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37193080

RESUMEN

Introduction: Fingolimod is a drug that is used to treat multiple sclerosis (MS). It has pH-dependent solubility and low solubility when buffering agents are present. Multi-spectroscopic and molecular modeling methods were used to investigate the molecular mechanism of Fingolimod interaction with human serum albumin (HSA), and the resulting data were fitted to the appropriate models to investigate the molecular mechanism of interaction, binding constant, and thermodynamic properties. Methods: The interaction of Fingolimod with HSA was investigated in a NaCl aqueous solution (0.1 mM). The working solutions had a pH of 6.5. Data was collected using UV-vis, fluorescence quenching titrations, FTIR, and molecular modeling methods. Results: According to the results of the fluorescence quenching titrations, the quenching mechanism is static. The apparent binding constant value (KA = 4.26×103) showed that Fingolimod is a moderate HSA binder. The reduction of the KA at higher temperatures could be a result of protein unfolding. Hydrogen bonding and van der Waals interactions are the main contributors to Fingolimod-HSA complex formation. FTIR and CD characterizations suggested a slight decrease in the α-helix and ß-sheets of the secondary structure of HSA due to Fingolimod binding. Fingolimod binds to the binding site II, while a smaller tendency to the binding site I was observed as well. The results of the site marker competitive experiment and the thermodynamic studies agreed with the results of the molecular docking. Conclusion: The pharmacokinetic properties of fingolimod can be influenced by its HSA binding. In addition, considering its mild interaction, site II binding drugs are likely to compete. The methodology described here may be used to investigate the molecular mechanism of HSA interaction with lipid-like drugs with low aqueous solubility or pH-dependent solubility.

9.
J Cosmet Dermatol ; 21(10): 5010-5017, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35226791

RESUMEN

INTRODUCTION: In recent years, argan oil has gained increasing interest in hair care products. In this study, attenuated total reflectance technique was utilized as a fast method and the results were compared to protein loss measurements in order to show the preventive effect of argan oil pre-treatment on excised human hair after oxidative hair damage. METHODS: Hair tresses were divided into three groups: in group-1; they were damaged using oxidant agent solely, in group-2 and 3; hair were pre-treated with argan oil before undergoing the oxidative damage. In group-2, the oil was removed by physical cleaning but in group-3 the oil was removed with a washing procedure. ATR (attenuated total reflectance) spectrum was recorded for different samples. Quantitative studies of protein loss in hair samples were performed by Lowry method. The antioxidant properties of argan oil were also measured in vitro using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) protocol, which determined the ability of the oil to scavenge the DPPH free radicals. RESULTS: The amount of protein loss with oil pre-treated groups was reduced significantly. The ATR spectrum showed oil deposition on hair even after washing. Four distinctive ATR peaks were changed during oxidation. The changes in peak height values were linear. The antioxidant property measured with DPPH method led to a IC50 value of 59 µg/ml. CONCLUSION: Argan oil pre-treatment was effective in protecting hair against oxidative damage. ATR outcomes were in accordance with protein loss results. In this study, the ATR testing method as a fast technique was used efficiently in quantification of hair damage.


Asunto(s)
Antioxidantes , Aceites de Plantas , Humanos , Antioxidantes/farmacología , Aceites de Plantas/farmacología , Estrés Oxidativo , Cabello
10.
J Cosmet Dermatol ; 20(1): 174-180, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32383548

RESUMEN

OBJECTIVES: Antioxidant containing cosmeceuticals are commonly prescribed products in treating wrinkles and revitalizing the skin. The aim of this study was the comparative evaluation of physicochemical stability and clinical anti-wrinkle efficacy of transdermal emulgel preparations of sodium ascorbyl phosphate (SAP) and ascorbic acid (AA) on human volunteers. METHODS: Emulgel preparations containing 5% of (SAP) and or (AA) were prepared. HPLC analysis was performed for stability evaluations. Clinical anti-wrinkle efficacy of the formulations was examined on human healthy volunteers in crow's feet area. Elasticity and digital images were recorded before and after treatment. RESULTS: Formulations with added antioxidants and kept in the refrigerator exhibited better stability characteristics. Two-sided blind study and placebo-controlled study showed that both actives were effective in wrinkles depth reduction and also elasticity enhancement but statistically significant difference in the efficacy of the products was not observed. CONCLUSION: Formulations containing (AA) and or (SAP) both improved elasticity and wrinkles of the skin almost by the same extent, and it is necessary to add antioxidant stabilizing agents to both preparations to reach a desired stability.


Asunto(s)
Envejecimiento de la Piel , Administración Cutánea , Ácido Ascórbico/análogos & derivados , Voluntarios Sanos , Humanos
11.
Pharm Dev Technol ; 15(6): 619-25, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19929166

RESUMEN

The enhancing effects of routinely used co-solvents, propylene glycol and 2-propanol, anionic and cationic surfactants and a co-surfactant with different concentrations were evaluated on the skin permeation of Finasteride. In vitro permeation experiments with rat skin revealed that the solvent mixture is a very important factor in the penetration of Finasteride through the skin. Unexpectedly, cationic and anionic surfactants in various concentrations did not show any enhancement effect on drug transdermal absorption but co-surfactant Transcutol P increased skin penetration of Finastride significantly. Transcutol P with 0.25% and 1% showed the best enhancement in the initial and final sampling time, respectively. Transcutol P in a concentration of 0.25% increased skin absorption of the drug nearly 3.6 times in the first 15 min. The highest enhancement ratio (ER) was gained in the presence of 1% Transcutol P (ER = 5.98). In this study, among the different topical Finastride formulations, Transcutol P 1% in combination with water, propylene glycol and 2-propanol (30, 10, and 60) showed the highest enhancement ratio.


Asunto(s)
Inhibidores de 5-alfa-Reductasa/farmacocinética , Excipientes/química , Finasterida/farmacocinética , Absorción Cutánea , Inhibidores de 5-alfa-Reductasa/administración & dosificación , Administración Cutánea , Animales , Glicoles de Etileno/química , Finasterida/administración & dosificación , Masculino , Ratas , Ratas Wistar , Solventes/química , Tensoactivos/química
12.
Clin Exp Dent Res ; 6(5): 506-511, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32592335

RESUMEN

OBJECTIVES: Oral lichen planus (OLP) is a chronic inflammatory disease of unknown etiology which is known as a premalignant disease. A complete cure has not been found for this condition. Mycophenolate mofetil (MMF) is a new drug that seems to be effective in improving OLP lesions. But there are no studies on the efficacy of mucoadhesive form of MMF in ulcerative OLP. Therefore, this study was performed to determine the therapeutic effect of MMF mucoadhesive on OLP lesions. MATERIAL AND METHODS: Twenty-seven patients with OLP, were enrolled in two groups. All the patients were instructed to place the MMF 2% mucoadhesive on the lesion twice daily for 4 weeks. Lesion size was measured by a sterile digital caulis (mm) and the severity of burning sensation and pain by visual analogue scale (VAS; cm) at baseline and weekly follow-ups. RESULTS: There was no significant difference in burning sensation and lesion size at Weeks 1, 2, and 3 in both groups. In Group A, at Week 4, there was significant reduction in pain and burning sensation and lesion size on both sides (p = .048, .012). The difference in lesion size on control sides was not significant. In Group B, at Week 4, there was significant reduction in pain and burning sensation and lesion size (p = .004). No side effects were reported by the patients. CONCLUSIONS: Based on the results, 2% MMF mucoadhesive was effective in decreasing burning sensation and pain severity and ulcer size of ulcerative OLP and the effect was time-dependent.


Asunto(s)
Liquen Plano Oral/tratamiento farmacológico , Ácido Micofenólico/administración & dosificación , Administración Tópica , Método Doble Ciego , Femenino , Humanos , Liquen Plano Oral/patología , Masculino , Persona de Mediana Edad , Mucosa Bucal , Resultado del Tratamiento
13.
J Integr Med ; 17(5): 344-350, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31201146

RESUMEN

BACKGROUND: Bloating is a common gastrointestinal complaint which is difficult to treat. OBJECTIVE: This study investigated the efficacy and compliance of a formulation called KAASER comprised of Trachyspermum ammi (L.) Sprague seed, Zingiber officinale Roscoe. rhizome and Piper nigrum L. berry in the treatment of functional bloating. DESIGN, SETTING, PARTICIPANTS AND INTERVENTION: A total of 106 patients with functional bloating, between 20 and 50 years of age, participated in this double-blind randomized controlled trial. Patients were divided into 3 parallel groups that received 500 mg of placebo, dimethicone or KAASER, three times a day for 2 weeks. MAIN OUTCOME MEASURES: The frequency and severity of bloating were primary outcomes, while the frequencies of eructation, defecation, borborygmus and early satiation were secondary outcomes. All parameters were evaluated at the beginning (week 0), and also weeks 2, 4 and 10 of the study, through self-report checklists with a scoring system. RESULTS: Among the 84 patients who completed the study, the frequency and severity of bloating (P < 0.001), the frequencies of eructation, defecation and borborygmus (P = 0.03) were significantly improved in the group receiving KAASER (36 patients) compared with the dimethicone (35 patients) and placebo (35 patients) groups, during the 3 phases of follow-up. These significant differences persisted through the 2 and 8 weeks of follow-ups after cessation of medication (week 4 and 10). In early satiation, no significant differences were observed among the 3 groups. CONCLUSION: The results showed that KAASER can be effectively used to treat patients suffering from bloating. Bloating, eructation, defecation and borborygmus in the KAASER group remained significantly improved after 2 and 8 weeks of cessation of medication, making this mechanism an interesting area for further investigation. TRIAL REGISTRATION: Registration trial IRCT2015100324327N on Iranian Registry of Clinical Trials.


Asunto(s)
Enfermedades Gastrointestinales/tratamiento farmacológico , Preparaciones de Plantas/uso terapéutico , Adulto , Método Doble Ciego , Femenino , Humanos , Irán , Masculino , Persona de Mediana Edad , Fitoterapia , Encuestas y Cuestionarios
14.
Eur J Pharm Biopharm ; 68(2): 289-97, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17616378

RESUMEN

A new type of elementary osmotic pump (EOP) tablet for efficient delivery of poorly water-soluble/practically insoluble drugs has been designed. Drug release from the system, called swellable elementary osmotic pump (SEOP), is through a delivery orifice in the form of a very fine dispersion ready for dissolution and absorption. SEOP tablets were prepared by compressing the mixture of micronized drug and excipients into convex tablets. Factors affecting the release of drug from the SEOP tablets containing a poorly water-soluble drug, indomethacin, have been explored. The release behaviour of indomethacin from different formulations of this dosage form was studied at pH 6.8 for a period of 24h. The formulations were compared based on four comparative parameters, namely, D(24h) (total release after 24h), t(L) (lag time), RSQ(zero) (R square of zero order equation) and D%(zero) (percentage deviation from zero order kinetics). The drug release profile from osmotic devices showed that the type of polymer in the core formulation can markedly affect the drug release. The results showed that concentration of wetting agent in the core formulation was a very important parameter in D(24h) and release pattern of indomethacin from SEOP system. Increasing the amount of wetting agent to an optimum level (60mg) significantly increased D(24h) and improved zero order release pattern of indomethacin. Increasing concentration of caster oil (hydrophobic) in the semipermeable membrane of the device or hydrophilic plasticizer (glycerin) in coating formulation markedly increased t(L) and decreased D(24h). The results also demonstrated that aperture size is a critical parameter and should be optimized for each SEOP system. Optimum aperture diameter for the formulations studied here was determined to be 650microm for zero order release pattern. t(L) and D%(zero) were dramatically decreased whereas D(24h) and RSQ(zero) increased with increasing the aperture size to optimum level. This study also revealed that optimization of semipermeable membrane thickness is very important for approaching zero order kinetics.


Asunto(s)
Sistemas de Liberación de Medicamentos , Ósmosis , Solubilidad , Agua
15.
Drug Deliv ; 15(1): 43-8, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18197523

RESUMEN

Oral osmotic devices including an elementary osmotic pump (EOP) are efficient systems for the delivery of drugs with high/moderately water-solubility. In this study we designed a new type of EOP for the efficient delivery of poorly water-soluble and practically insoluble drugs. In this system, called swellable elementary osmotic pump (SEOP), drug is released from the delivery orifice in the form of a very fine dispersion of drug in gel which is ready for dissolution and absorption. Factors affecting the release of drug from the SEOP containing a poorly water-soluble drug, nifedipine, were explored extensively. To this end, effect of swelling and wetting agents, orifice size, concentration of osmotic agent, and hydrophobic plasticizer were investigated. Interestingly, in the absence or low concentration of a hydrophobic plasticizer (caster oil), the osmotic devices did not retain their integrity in dissolution media. Caster oil in concentration of > 1% was necessary for tablets to retain their integrity during dissolution process. A zero-order release kinetics for nifedipine was achieved following the effective optimization of the concentrations of swelling agent, osmotic agent, wetting agent, and also size of orifice and membrane thickness in SEOP. The zero-order release lasted for 10 hr at pH 6.8 dissolution medium. The designed SEOP is suggested as an efficient controlled delivery system for oral delivery of a poorly water soluble drug such as nifedipine.


Asunto(s)
Celulosa/análogos & derivados , Portadores de Fármacos , Membranas Artificiales , Nifedipino/química , Administración Oral , Aceite de Ricino/química , Celulosa/química , Química Farmacéutica , Preparaciones de Acción Retardada , Composición de Medicamentos , Geles , Concentración de Iones de Hidrógeno , Derivados de la Hipromelosa , Cinética , Metilcelulosa/análogos & derivados , Metilcelulosa/química , Modelos Químicos , Nifedipino/administración & dosificación , Ósmosis , Permeabilidad , Plastificantes/química , Cloruro de Potasio/química , Dodecil Sulfato de Sodio/química , Solubilidad , Comprimidos , Agua/química , Agentes Mojantes/química
16.
J Cosmet Dermatol ; 17(6): 1225-1232, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29178604

RESUMEN

BACKGROUND: Polyquaterniums (PQs) as important ingredients of hair products are synthetic cationic polymers and are used in commercial hair volumizers and conditioners. METHODS: Three different grades of polymers including PQ 87, 68, and 46 with various concentrations were used, and their hair deposition efficacy was measured at 5 different pH values using hair diameters measurements by digital micrometer. Deposition durability of polymer layer on the hair surface was tested by a defined washing test. Optical microscopic images and polarized light images were also taken from treated and untreated samples for further investigation. Attenuated total reflectance (ATR) spectral were recorded from hair samples to prove the polymer deposition and probable interaction with hair fibers. RESULTS: PQ-68 with the highest molecular weight (300 kDa) at pH = 9 exhibited the best hair deposition efficacy. The results revealed that the deposition of polymers is directly proportional to the pH values. The best results were seen at pH = 9, and at the lowest pH (pH = 5), the efficiency of polymers was approximately equal to zero. The best resistance against washing was shown by PQ-44 at pH = 6. ATR successfully tracked the presence of the polymers on the hair fibers and also proposed specific wave numbers for each polymeric agent, individually. CONCLUSIONS: In general, two main parameter which can mainly influence the deposition efficacy of PQs are the type of polymer or its molecular weight and also the positive charge density on the polymer molecules.


Asunto(s)
Preparaciones para el Cabello/farmacología , Cabello/efectos de los fármacos , Polímeros/farmacología , Compuestos de Amonio Cuaternario/farmacología , Femenino , Cabello/patología , Humanos , Peso Molecular , Técnicas de Cultivo de Tejidos
17.
Acta Pharm ; 68(3): 325-336, 2018 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-31259692

RESUMEN

The study was conducted to enhance the dissolution rate of ketoconazole (KCZ) (a poorly water-soluble drug) using the liquisolid technique. Microcrystalline cellulose, colloidal silica, PEG400 and polyvinyl pyrrolidone (PVP) were employed as a carrier, coating substance, nonvolatile solvent and additive in the KCZ liquisolid compact formulation, respectively. The drug-to-PEG400 and carrier-to-coating ratio variations, PVP concentration and aging effects on the in vitro release behavior were assessed. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) data revealed no alterations in the crystalline form of the drug and the KCZ-excipient interactions within the process. The load factor and the drug release rate were significantly enhanced compared to directly compressed tablets in the presence of the additive. Increasing the PEG400-to-drug ratio in liquid medications enhanced the dissolution rate remarkably. The dissolution profile and hardness of liquisolid compacts were not significantly altered by keeping the tablets at 40 °C and relative humidity of 75 % for 6 months. With the proposed modification of the liquisolid process, it is possible to obtain flowable, compactible liquisolid powders of high-dose poorly-water soluble drugs with an enhanced dissolution rate.


Asunto(s)
Química Farmacéutica/métodos , Portadores de Fármacos/química , Excipientes/química , Cetoconazol/química , Rastreo Diferencial de Calorimetría , Celulosa/química , Liberación de Fármacos , Cetoconazol/administración & dosificación , Polietilenglicoles/química , Povidona/química , Dióxido de Silicio/química , Solubilidad , Solventes/química , Comprimidos , Tecnología Farmacéutica/métodos , Difracción de Rayos X
18.
Bioimpacts ; 7(4): 207-208, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29435427

RESUMEN

Various nanomaterials/nanoparticles (NPs) have been used for the development of cosmetic products - a field so-called nanocosmetic formulations. These advanced materials offer some benefits, while their utilization in the cosmetic formulations may be associated with some risks. The main aim of this editorial is to highlight the benefits and risks of the nanomaterials used in the cosmetic products.

19.
Bioimpacts ; 7(1): 5-12, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28546948

RESUMEN

Introduction: The potential of combining liquisolid and co-grinding technologies (liquiground technique) was investigated to improve the dissolution rate of a water-insoluble agent (glibenclamide) with formulation-dependent bioavailability. Methods: To this end, different formulations of liquisolid tablets with a wide variety of non-volatile solvents contained varied ratios of drug: solvent and dissimilar carriers were prepared, and then their release profiles were evaluated. Furthermore, the effect of size reduction by ball milling on the dissolution behavior of glibenclamide from liquisolid tablets was investigated. Any interaction between the drug and the excipient or crystallinity changes during formulation procedure was also examined using X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Results: The present study revealed that classic liquisolid technique did not significantly affect the drug dissolution profile as compared to the conventional tablets. Size reduction obtained by co-grinding of liquid medication was more effective than the implementation of liquisolid technique in enhancing the dissolution rate of glibenclamide. The XRD and DSC data displayed no formation of complex or any crystallinity changes in both formulations. Conclusion: An enhanced dissolution rate of glibenclamide is achievable through the combination of liquisolid and co-grinding technologies.

20.
Colloids Surf B Biointerfaces ; 153: 27-33, 2017 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-28208062

RESUMEN

In controlled porosity osmotic pumps (CPOP), usually finding a single solvent with a capability to dissolve both film former (hydrophobic) and pore former (hydrophilic) is extremely challenging. Therefore, the aim of the present investigation was to tackle the issue associated with controlled porosity osmotic pump (CPOP) system using nano-suspension coating method. In the present study 4-Amino pyridine was used as a highly water soluble drug. In this method, a hydrophilic pore former (sucrose or mannitol) in nano range was suspended in polymeric coating solution using ball-mill. The performance of the prepared formulations was assessed in terms of D12h (cumulative release percent after 12h), Devzero (mean percent deviation of drug release from zero order kinetic), tL (lag time of the drug release) and RSQzero. The results revealed that gelling agent amount (HPMC E15LV) in core and pore former concentration in SPM had crucial effect on SPM integrity. All the optimised formulations showed a burst drug release due to fast dissolving nature of the pore formers. Results obtained from scanning electron microscopy demonstrated the formation of nanopores in the membrane where the drug release takes place via these nanopores. Nano suspension coating method can be introduced as novel method in formulation of CPOPs.


Asunto(s)
4-Aminopiridina/química , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Nanotecnología/métodos , Ósmosis , Interacciones Hidrofóbicas e Hidrofílicas , Tamaño de la Partícula , Porosidad , Solubilidad , Propiedades de Superficie , Suspensiones/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA