Cetyl Palmitate Research Articles

Liquid Crystal Formation from Sunflower Oil: Long Term Stability Studies.

The Brazilian biodiversity offers a multiplicity of raw materials with great potential in cosmetics industry applications. Some vegetable oils and fatty esters increase skin hydration by occlusivity, keeping the skin hydrated and with a shiny appearance. Sunflower (Helianthus annus L.) oil is widely employed in cosmetic emulsions in the form of soaps, creams, moisturizers and skin cleansers due to the presence of polyphenols and its high vitamin E content. Liquid crystals are systems with many applications in both pharmaceutical and cosmetic formulations and are easily detected by microscopy under polarized light due to their birefringence properties. The aim of this research was to develop emulsions from natural sunflower oil for topical uses. Sunflower oil (75.0% w/w) was combined with liquid vaseline (25.0% w/w) employing a natural self-emulsifying base (SEB) derivative. The high temperature of the emulsification process did not influence the antioxidant properties of sunflower oil. Fatty esters were added to cosmetic formulations and extended stability tests were performed to characterize the emulsions. Fatty esters like cetyl palmitate and cetyl ester increase the formation of anisotropic structures. O/W emulsions showed acidic pH values and pseudoplastic behavior. The presence of a lamellar phase was observed after a period of 90 days under different storage conditions.

Esterification of cetyl alcohol with palmitic acid over WO3/Zr-SBA-15 and Zr-SBA-15 catalysts

Tungsten loaded and Zr incorporated SBA-15 catalysts (WO3/Zr-SBA-15 and Zr-SBA-15) were developed for esterification of cetyl alcohol and palmitic acid. The influence of the Zr content, tungsten loading amount, calcination temperature, feed composition and catalyst amount has been studied. Higher tungsten loading decreased the acidity due to formation of WO3 crystals whereas calcination temperature enhanced the acidity by favoring the dispersion of WOx species. Activities of the catalyst changed depending on their amount of Brønsted sites and total number of acid sites. Zr-SBA-15 catalyst which had the highest amount of Brønsted acid sites gave maximum cetyl palmitate yield (63.1%). This catalyst retained its activity up to 3 reuse cycles without significant loss of activity.

Rapamycin Loaded Solid Lipid Nanoparticles as a New Tool to Deliver mTOR Inhibitors: Formulation and in Vitro Characterization.

Recently, the use of mammalian target of rapamycin (mTOR) inhibitors, in particular rapamycin (Rp), has been suggested to improve the treatment of neurodegenerative diseases. However, as Rp is a strong immunosuppressant, specific delivery to the brain has been postulated to avoid systemic exposure. In this work, we fabricated new Rp loaded solid lipid nanoparticles (Rp-SLN) stabilized with polysorbate 80 (PS80), comparing two different methods and lipids. The formulations were characterized by differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), wide angle X-ray scattering (WAXS), cryo-transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS) and particle tracking. In vitro release and short-term stability were assessed. Biological behavior of Rp-SLN was tested in SH-SY5Y neuroblastoma cells. The inhibition of mTOR complex 1 (mTORC1) was evaluated over time by a pulse-chase study compared to free Rp and Rp nanocrystals. Compritol Rp-SLN resulted more stable and possessing proper size and surface properties with respect to cetyl palmitate Rp-SLN. Rapamycin was entrapped in an amorphous form in the solid lipid matrix that showed partial crystallinity with stable Lβ, sub-Lα and Lβ′ arrangements. PS80 was stably anchored on particle surface. No drug release was observed over 24 h and Rp-SLN had a higher cell uptake and a more sustained effect over a week. The mTORC1 inhibition was higher with Rp-SLN. Overall, compritol Rp-SLN show suitable characteristics and stability to be considered for further investigation as Rp brain delivery system.

Electroporation and lipid nanoparticles with cyanine IR-780 and flavonoids as efficient vectors to enhanced drug delivery in colon cancer

Nanocarriers and electroporation (also named electropermeabilization) are convenient methods to increase drug transport. In the current study, we present an effective support of drug delivery into cancer cells, utilizing these methods. We compare the efficiency of each of them and their combination. Multifunctional solid lipid nanoparticles (SLNs) loaded with a cyanine-type IR-780 — acting as a diagnostic agent and a photosensitizer, and a flavonoid derivative — baicalein (BAI) or fisetin (FIS) as a therapeutic cargo — were fabricated via solvent-diffusion method. A therapy supplemented with flavonoids may provide a more precise method to apply desirable lower drug doses and is more likely to result in lower toxicity and a decrease in tumor growth. The SLNs were stabilized with Phospholipon 90G at various concentrations; cetyl palmitate (CP) was applied as a solid matrix. The obtained nanosystems were characterized by dynamic light scattering (size along with size distribution), UV–vis (cargos encapsulation efficiency) and atomic force microscopy (morphology and shape). The obtained SLNs were used as drug carriers alone and in combination with electropermeabilization induced by millisecond pulsed electric fields of high intensity.Two cell lines were selected for the study: LoVo and CHO-K1. The viability was assessed after electroporation alone, the use of electroporation and nanoparticles, and nanoparticles or drugs alone. The intracellular accumulation of cyanine IR-780 and the impact on intracellular structure organization of cytoskeleton was visualized with confocal microscopy method with alpha-actin and beta-tubulin. In this study, the efficacy of nanoparticles with mixed cargo, additionally enhanced by electroporation, is demonstrated to act as an anticancer modality to eliminate cancer cells.

Solvent-free enzymatic production of high quality cetyl esters.

A solvent-free biocatalytic process for the synthesis of high quality cetyl laurate, myristate, palmitate and stearate has been optimized. This enzymatic procedure follows the fundamental principles of the Green Chemistry and lead to sustainable products, which can be labeled as natural and conform to the principal requirements for its use in high value-added goods. The four esters selected are the main components of spermaceti, a mixture of waxes very appreciated in cosmetic and pharmacy because of its physical properties and emolliency, which was formerly extracted from the head of the sperm whales. In this paper, the influence of the amount of biocatalyst, the commercially available Novozym(®) 435, and the temperature were studied in an open-air batch reactor before carrying out the synthesis in a high performance vacuum reactor with dry nitrogen input to shift the equilibrium towards product formation. Under optimal conditions, conversion was higher than 98.5 %. The characterization of the enzymatic cetyl esters puts in evidence that these are ultra-pure compounds, which have similar properties to the ones obtained through the conventional industrial processes with the extra benefit of being environmentally friendly.

Formulation, Characterisation, and in Vitro Skin Diffusion of Nanostructured Lipid Carriers for Deoxyarbutin Compared to a Nanoemulsion and Conventional Cream.

The long-term use of topical hydroquinone as an anti-hyperpigmentation treatment has well-known, unwanted effects. Deoxyarbutin (4-[(tetrahydro-2H-pyran-2-yl)oxy]phenol) is a relatively new tyrosinase inhibitor, with stronger inhibitory potency than hydroquinone, that exhibited decreased cytotoxicity against melanocytes and other cells. This study developed novel nanostructured lipid carriers (NLCs) for improved topical delivery of deoxyarbutin (dArb), leading to improved depigmenting efficacy. dArb is a hydrophobic substance, but it easily degrades in aqueous medium and is thermolabile. Screening and optimisation of the solid lipid, liquid lipid, surfactant, co-surfactant and production methods were performed to choose the optimum particle size and stability for NLCs. One percent dArb NLCs were obtained from a combination of cetyl palmitate (CP) and caprylic/capric tryglicerides (Myr) in 12% total lipids using poloxamer 188 (P-188) and polyethylene glycol (PEG) 400 as a surfactant and co-surfactant, respectively, with a particle diameter of approximately 500 nm and a polydispersity index (PI) <0.4. These NLCs were produced using the simple method of high-shear homogenisation (10,000 rpm, 5 minutes) and ultrasonication (3.5 min). The compatibility between the substances in the formula was evaluated using Fourier Transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The morphology of the NLCs was observed using transmission electron microscopy (TEM). In vitro penetration of dArb NLCs was evaluated and compared to the nanoemulsion (NE) and conventional emulsion (CR) delivery methods across Spangler’s membrane (SS). Delivery improvement was clearly observed, and after 8 h of application, dArb gel-NLCs showed the highest dArb penetration, followed by liquid NLCs, NE, and CR.

α-Tocopherol을 함유한 Nanostructured Lipid Carriers의 특성과 안정화 효과

Loading of hydrophobic α-tocopherol into nanostructured lipid carrier (NLC) was performed for improving its oxidative stability. First, various NLCs with different constituents and mixing ratios were prepared and their characteristics were investigated. While the stable NLCs were made when cetyl palmitate (CP) or glyceryl monosterate (GMS) was used as a solid lipid, the phase separation occurred in the NLCs consisting of stearic acid. Particle sizes of the NLCs were several hundreds of nanometers and the size decreased with increasing the ratio of solvent to lipid. It was examined from DSC thermogram and anisotropy test that the degree of crystallinity of the lipid phase decreased and the lipid matrix became less ordered when octyldodecanol, a long chain fatty alcohol, was added into the solid lipid. The oxidative stability of α -tocopherol in NLC was remarkably improved compared to that in solution or emulsion under high temperature (45 °C) and UV radiation, which was verified through DPPH test and peroxide value measurement.

Radar charts based on particle sizing as an approach to establish the fingerprints of polymeric nanoparticles in aqueous formulations

Pre-formulation studies are conducted each time new nanoparticulate formulations are in development to the selection of a satisfactory drug delivery system. We hypothesized that laser diffraction technique could be used as an initial screening, being an excellent tool to save time and reduce the number of necessary tests to select formulations. We built radar charts based on laser diffraction data as a new approach to determine the fingerprints of nanocarrier formulations in order to select promising drug delivery systems. To validate our approach different lipophilic dispersions of poly(epsilon-caprolactone) and polysorbate 80, combined with 4 solid materials: sorbitan monostearate (I), cetyl palmitate (II), stearic acid (III) or cholesterol (IV), and 4 oils: capric/caprylic triglycerides (A), mineral oil (B), octyl methoxycinnamate (C) or oleic acid (D), were prepared. Formulations were analyzed by laser diffraction, as well as considering the visual appearance, pH, organic phase viscosity, hydrodynamic diameter, polydispersity index, zeta potential and in vitro drug release. Specific fingerprints were determined for formulations having unimodal particle size distributions with low polydispersity. On the other hand, formulations showing multimodal particle size distributions were rapidly identified in the radar charts and classified as noncompliance products.

Hot homogenization process optimization for fragrance encapsulation in solid lipid nanoparticles

AbstractSolid lipid nanoparticles (SLNs) loaded with perfume were prepared using a hot homogenization process coupled with ultrasounds. The objective was to develop a simple process adjustable to several kinds of lipids. The process comprised two steps: a pre‐emulsion of the melted lipids in water followed by a size reduction by sonication, before cooling. The study of several formulation parameters showed that the size distribution of SLNs depended essentially on the sonication step, and especially on the ultrasounds power and time. Five types of SLNs loaded with perfume were produced, based on petrolatum, candelilla, shea butter, C10‐18 triglycerides, and cetyl palmitate. The size distribution was below 200 nm with a narrow size distribution. Moreover, high encapsulation efficiency was obtained, at least 66.5% (±0.5) for petrolatum SLNs and 94.9% (±0.5) for cetyl palmitate SLNs and the loading % was comprised between 4.9% (±0.5) (petrolatum) and 7.0% (±0.5) (cetyl palmitate). A correlation between the partition coefficient of the molecules and the encapsulation efficiency was established for all lipids except cetyl palmitate. Cetyl palmitate, candelilla and petrolatum SLNs were stable for at least one month at 4 °C and 25 °C. Copyright © 2015 John Wiley &amp; Sons, Ltd.

Polymeric Versus Lipid Nanoparticles: Comparative Study of Nanoparticulate Systems as Indomethacin Carriers

Encapsulation of nonsteroidal or non-steroidal anti-inflammatory drugs (NSAID) in nanocarrier systems aims to enhance bioavailability and to decrease toxicity of these drugs and thus improve the efficacy of treatments. With this aim two types of nanoparticles were prepared and compared: lipid nanoparticles, made of cetyl palmitate and Miglyol 812 which were uncoated or coated with chitosan; or polymeric nanoparticles, made of poly (DL-lactic-co-glycolic acid) (PLGA) for which different emulsion stabilizers were also tested (poly (vinyl alcohol) (PVA), and Pluronic F68). Nanoparticles were characterized for drug content and for particle size, charge and morphology. The lipid matrix was analyzed regarding its crystallinity by differential scanning calorimetry (DSC). The size of the nanoparticles was measured by dynamic light scattering (DLS) which indicated a unimodal particle size distribution in all systems. Nanoparticles' stability was confirmed by their highly negative surface charge in the case of polymeric and uncoated lipid nanoparticles, as analyzed by zeta potential measurements using electrophoretic light scattering (ELS). Lipid chitosan coated nanoparticles have also shown to be stable presenting highly positive surface charge. Results have further demonstrated that indomethacin is highly encapsulated regardless the type of particles. Morphological analysis by scanning electron microscopy has shown that the nanoparticles were smooth and spherical. The results gathered within the current study point to the conclusion that the proposed formulations provide nanoparticles of satisfactory quality to encapsulate indomethacin, which might be used to improve bioavailability of other NSAID in the treatment of inflammation.

Active Targeting of Sorafenib: Preparation, Characterization, and In Vitro Testing of Drug-Loaded Magnetic Solid Lipid Nanoparticles.

Sorafenib is an anticancer drug approved by the Food and Drug Administration for the treatment of hepatocellular and advanced renal carcinoma. The clinical application of sorafenib is promising, yet limited by its severe toxic side effects. The aim of this study is to develop sorafenib-loaded magnetic nanovectors able to enhance the drug delivery to the disease site with the help of a remote magnetic field, thus enabling cancer treatment while limiting negative effects on healthy tissues. Sorafenib and superparamagnetic iron oxide nanoparticles are encapsulated in solid lipid nanoparticles by a hot homogenization technique using cetyl palmitate as lipid matrix. The obtained nanoparticles (Sor-Mag-SLNs) have a sorafenib loading efficiency of about 90% and are found to be very stable in an aqueous environment. Plain Mag-SLNs exhibit good cytocompatibility, whereas an antiproliferative effect against tumor cells (human hepatocarcinoma HepG2) is observed for drug-loaded Sor-Mag-SLNs. The obtained results show that it is possible to prepare stable Sor-Mag-SLNs able to inhibit cancer cell proliferation through the sorafenib cytotoxic action, and to enhance/localize this effect in a desired area thanks to a magnetically driven accumulation of the drug. Moreover, the relaxivity properties observed in water suspensions hold promise for Sor-Mag-SLN tracking through clinical magnetic resonance imaging.

Multifunctional di-N-oxide surfactants in fabrication of lipid nanoparticles

A homologous series of dicephalic surfactants, 1,1-bis{[3-(N,N-dimethylamino)ethyl]amido}alkane-di-N-oxides (CnMEDA), is reported, and their applicability for stabilization of the lipid nanoparticles (solid lipid nanoparticles (SLNs) or nanostructured lipid carriers (NLCs)) is discussed and compared with that of their counterparts, single-head–single-tail 2-alkanoylamino)ethyldimethylamines (CnEDA). For the SLN formation, solid cetyl palmitate (Crodamol CP-PA-(SG) is applied as the solid lipid, and in the case of NLCs, cetyl palmitate and triglycerides of caprylic/capric are applied as the liquid lipid. Structural parameters of the resulting nanoparticles are characterized by dynamic light scattering, transmission electron microscopy and scanning electron microscopy and thermal behavior by differential scanning calorimetry (DSC). The studied nanoparticles stabilized with dicephalic CnMEDA had a mean diameter of about 145 nm, whereas the particle size of those stabilized with CnEDA is around 160 nm. Zeta potential measurements demonstrated a negative charge of all obtained SLNs and NLCs, and their values are between −7 and −20 mV. These characteristics remained unchanged for samples stabilized with CnMEDA for least 3 months, suggesting good stability. According to the DSC findings, the NLCs stabilized by the tested CnMEDA had lower values for phase transition temperature, melting enthalpy and the recrystallization index than those obtained for the SLNs. The obtained findings suggest that less ordered crystalline structure is conferred by the inclusion of the liquid lipid. Moreover, the SLNs and NLCs stabilized by dicephalic surfactants constitute more stable products than those stabilized by their linear counterparts.

PH-controlled delivery of curcumin from a compartmentalized solid lipid nanoparticle@mesostructured silica matrix.

Silicalization of curcumin-loaded solid lipid nanoparticle (SLN)/micelle dispersions afforded a compartmentalized nanovector, with both macro- and mesostructured domains. SLNs act as reservoirs of curcumin (CU), while mesopores act as pathways to control drug release. Moreover, the release sustainability depends on the nature of the solid lipid (cetyl palmitate vs. stearic acid) and on the pH of the receiving phase. The meso-macrostructured silica matrix templated by SLNs appears thus as a promising drug delivery system for pH-responsive controlled release.

Formulation of solid lipid nanoparticles (SLN): The value of different alkyl polyglucoside surfactants

Alkyl polyglycosides (APGs) represent a group of nonionic tensides with excellent skin compatibility. Thus they seem to be excellent stabilizers for lipid nanoparticles for dermal application. To investigate this, different APGs were selected to evaluate their influence on the formation and characteristics of solid lipid nanoparticles (SLN). Contact angle analysis of the aqueous solutions/dispersions of the APGs on cetyl palmitate films revealed good wettability for all APG surfactants. Cetyl palmitate based SLN were prepared by hot high pressure homogenization and subjected to particle size, charge and inner structure analysis. 1% of each APG was sufficient to obtain SLN with a mean size between 150nm and 175nm and a narrow size distribution. The zeta potential in water was ∼ −50mV; the values in the original medium were distinctly lower, but still sufficient high to provide good physical stability. Physical stability at different temperatures (5°C, 25°C and 40°C) was confirmed by a constant particle size over an observation period of 90 days in all dispersions. In comparison to SLN stabilized with classical surfactants, e.g., Polysorbate, APG stabilized SLN possess a smaller size, improved physical stability and contain less surfactant. Therefore, the use of APGs for the stabilization of lipid nanoparticles is superior in comparison to classical stabilizers. Further, the results indicate that the length of the alkyl chain of the APG influences the diminution efficacy, the final particle size and the crystallinity of the particles. APGs with short alkyl chain led to a faster reduction in size during high pressure homogenization, to a smaller particle size of the SLN and to a lower recrystallization index, i.e., to a lower crystallinity of the SLN. The crystallinity of the SLN increased with an increase in the alkyl chain length of APGs. Therefore, by using the tested APGs differing in the alkyl chain length, not only small sized and physically stable but also SLN with different sizes and crystallinity can be obtained. An optimized selection of these stabilizers might therefore enable the production of lipid nanoparticles with “tailor-made” properties.

Effect of vegetable oils on obtaining lipid nanocarriers for sea buckthorn extract encapsulation

The principal aim of the present study was to develop new safe and highly antioxidant nanostructured lipid carriers loaded with sea buckthorn extract. Three vegetable oils — grape seed oil, sea buckthorn oil and St. John's wort oil ( Hypericum perforatum oil) — were used as matrix components and the modified high shear homogenization technique has been employed for the synthesis of nanostructured materials. The effect of these oils on the antioxidant and antimicrobial activities of loaded sea buckthorn extract — nanostructured lipid carriers — has also been studied. For this purpose, a combination of two solid lipids: cetyl palmitate with glyceryl stearate and lecithin/block copolymer has been used. The obtained nanostructured lipid carriers have been characterized for the particle size and zeta potential by means of dynamic light scattering measurements. The nano-dimension morphology of loaded nanostructured lipid carriers was confirmed by transmission electron microscopy. Their crystallinity measured by differential scanning calorimetry has revealed a high disordered lipid matrix. The properties of sea-buckthorn-extract-loaded nanoparticles have been evaluated by an appropriate in vitro analysis (chemiluminescence method). The presence of the three vegetable oils influences extensively the antioxidant properties of the developed nano-formulations, as has been demonstrated using the chemiluminescence technique. The antimicrobial activity of the studied nanostructured lipid carriers, analyzed by the diffusion disc method, shows in most of the samples a high efficiency against Escherichia coli bacteria.

Idebenone loaded solid lipid nanoparticles: calorimetric studies on surfactant and drug loading effects.

In this study we prepared solid lipid nanoparticles (SLN), by the phase inversion temperature (PIT) method, using cetyl palmitate as solid lipid and three different non-ionic emulsifiers of the polyoxyethylene ethers family (ceteth-20, isoceteth-20, oleth-20). These SLN were loaded with different amount of idebenone (IDE), an antioxidant drug useful in the treatment of neurodegenerative diseases and skin oxidative damages. The differential scanning calorimetry (DSC) was employed to evaluate the effects of the different emulsifiers and the different amounts of drug loaded on the thermotropic behavior of SLN and to investigate how the drug was arranged into these nanoparticles. The IDE seemed to be located into different regions of the SLN depending on its concentration and on the surfactant used. The results of this study suggest that the calorimetric studies performed on SLN could provide valuable information to optimize SLN design and drug release from these carriers.

Solid Lipid Nanoparticles as Indomethacin Carriers for Topical Use ( 2 ) : DSC Analysis , Drug Release and Rheological Properties = الجسيمات الدهنية الصلبة النانوية كناقلات الإندوميثاسين للاستخدام الموضعي : المسح التفاضلي الحراري ، انطلاق الدواء و الخواص الريولوجية

Solid lipid nanoparticles (SLNs) and nano structured lipid carriers (NLCs) containing or not containing indomethacin (IND) were prepared with either Cetyl palmitate, GeleolTM, or Compritol® 888 ATO as a lipid phase by the hot homogenization technique. In all systems the surfactant was sucrose fatty acid ester SP 30 (HLB 6.0). Differential scanning calorimetry (DSC) experiments were carried out on the freeze - dried samples for all developed plain and drug- loaded formulations after one month of storage at room temperature. The recorded DSC parameters of the samples were compared with those of pure components and physical mixtures of IND with the surfactant or lipids at equivalent ratios to that in nanoparticualtes. Furthermore, rheological analyses of the empty and loaded systems, release experiments at pH 5.0 and the release kinetics were all investigated. This study focuses on the investigation of how the nature and the amount of formulation components are able to modify the properties of the system. In particular, the concentration of the surfactant used for the nanosuspension stabilization, the nature and concentration of the lipid phase used for the nanoparticles preparation, as well as the drug- lipid ratio employed in the preparation of loaded SLNs were investigated. DSC results showed crystalline particles at room temperature exhibited a shift of the melting endotherm of the lipid phase, with the maximum at a temperature value higher than that of the empty or loaded SLNs except in GeleolTM - based systems. For the investigated formulations a percentage of crystallinity between 61.0 % and 88.33 % was found. Furthermore, IND suffered a marked reduction in its crystallinity and had better solubility in both GeleolTM and Compritol® 888 ATO as compared to Cetyl palmitate screened. Hydrogen bonding with glyceride containing lipids can be one reason for the observed loss of IND crystallinity. All formulations were of creamy texture and viscous especially GeleolTM - based systems. Rheological analysis confirmed that all systems show a complete dependence of the viscosity from the shear stress. The release profiles of different formulations at pH 5.0 allow affirming that these systems are suitable for modified topical delivery. Release studies showed that IND exhibited a prolonged slow release over 24 hours (hrs) with release kinetics in general following zero order model and there was insignificant difference in the amount of released drug depending upon the composition of the formulations.

Antioxidant and antimicrobial activities of green tea extract loaded into nanostructured lipid carriers

Abstract In this paper, the preparation and characterization of some novel nanostructured lipid carriers for drug delivery are reported. They are obtained by mixing two solid lipids, cetyl palmitate and glyceryl stearate, with three types of vegetable oils: grape seed oil, St. John's wort oil ( Hypericum perforatum oil) and sea buckthorn oil. In order to increase their antioxidant and antimicrobial properties, they are co-loaded with green tea extract by using a modified high shear homogenization technique. Size distribution and polydispersity index of the developed nanostructured lipid carriers determined by the dynamic light scattering, and corroborated with the results obtained by the transmission electron microscopy analysis, confirmed that the structures obtained are at nanoscales. The crystallinity behavior of the prepared nanostructured lipid carriers has been studied by differential scanning calorimetry; zeta potential measurements show that all loaded nanostructures present excellent physical stability. Their antioxidant and antimicrobial properties evaluated by an appropriate in vitro analysis using the chemiluminescence method, and the diffusion disc method, respectively, show that green tea extract could be utilized as a valuable natural source of antioxidant and antimicrobial agent. These new nano-formulations proved to have significant potential for nutritional and pharmaceutical applications.

Improved brain delivery of vincristine using dextran sulfate complex solid lipid nanoparticles: Optimization and in vivo evaluation

Vincristine (VC) sulfate, a freely water-soluble cytotoxic agent was incorporated into cetyl palmitate solid lipid nanoparticles (SLNs) with the aid of dextran sodium sulfate (DS), a poly anion, using a microemulsion method. The manufacturing process was optimized using response surface methodology (Box-Behnken design). SLNs were characterized for size, zeta potential, morphology, crystallinity, and release behavior. The drug encapsulation efficiency reached up to 93% and release study revealed sustained drug release. SLN formulation showed comparable cytotoxic effect in comparison to VC sulfate solution against the MDA-MB-231 cells. The in vivo studies following injection to rat revealed higher plasma and tissue concentrations and longer drug mean residence times compared to VC solution. Using cumarin-6 as a model drug, it was shown that drug delivery to the brain was enhanced close to five times using SLNs prepared in this study compared to free cumarin-6. It can be concluded that complexes of cetyl palmitate SLNs with DS could produce high VC-loaded SLNs suitable for delivery of anticancer drugs to brain tumors.

Thermal characterization and compatibility studies of itraconazole and excipients for development of solid lipid nanoparticles

The current study was performed to investigate possible interactions between triazole antifungal drug itraconazole (ITR) with selected excipients commonly used for development of solid lipid nanoparticles. The excipients included common lipids (glyceryl behenate (Compritol 888 ATO™), glyceryl monostearate, stearic acid, and cetyl palmitate), charge inducers (dicetyl phosphate and stearlyamine), and surfactants (sodium cholate and sodium deoxycholate). Differential scanning calorimetry, isothermal stress testing, Fourier transform infrared spectral analysis, optical microcopy, and X-ray powder diffraction analysis were performed for assessing the compatibility between the drug and the excipients. Results of the study suggest that the stearic acid exhibited drug–excipient interactions, whereas all other excipients used in the study were found to be compatible with ITR.