Preparation, in Vitro and in Vivo Evaluation of Liposomal/Niosomal Gel Delivery Systems for Clotrimazole

Clotrimazole, which is an imidazole derivative antifungal agent, was widely used for the treatment of mycotic infections of the genitourinary tract. To develop alternative formulation for the vaginal administration of clotrimazole to provide sustained and controlled release of appropriate drug for local vaginal therapy, liposomes/niosomes were evaluated as delivery vehicles. To optimize the preparation of liposomes/niosomes with regard to size and entrapment efficiency, multilamellar liposomes/niosomes containing drug were prepared by lipid hydration method. The prepared liposomes/niosomes were incorporated into 2% carbopol gel, and the systems were evaluated for drug stability in phosphate-buffered saline (pH 7.4) and simulated vaginal fluid at 37 ± 1°C. Further, the vesicle gel system was evaluated by antifungal activity and tolerability on tissue level in rat.     

Characterization of amphotericin B liposome formulations

Liposomes composed of hydrogenated soya phosphatidylcholine (Emulmetik 950®)/cholesterol/charged lipids [dicetyl phosphate (-) or stearylamine (+)] were developed. The hydrogenated soya phosphatidylcholine/cholesterol/charged lipid liposomes at molar ratios of 1:1:0, 7:2:0, 7:2:1 (-), and 7:2:1 (+), with and without the entrapped amphotericin B (0.05 mg AmB/mg lipid), were prepared by a chloroform-film method with sonication. The charges of liposomes were characterized by a Zeta-Meter. The negative liposomes with and without the entrapped AmB showed higher surface charge density than other formulations. The size distribution of liposomes determined by standard error of the mean (SEM) was in the range of 0.115 to 0.364 µm. The smallest size was observed in the negative liposomes with the entrapped drug [7:2:1 (-) AmB]. The lamellarity of more than 15 layers was observed by transmission electron microscope (TEM) in the neutral liposomes with the entrapped drug [7:2 AmB]. The transition temperature and enthalpy of transition (ΔH) were determined by differential scanning calorimetry (DSC). Positive liposomes with the entrapped and unentrapped AmB demonstrated higher ΔH of the first peak than other formulations, indicating higher rigidity of liposomal membrane. The AmB contents in liposomes were determined by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection at 382 nm. The percentages of entrapment of AmB in all formulations were above 85%. The positive liposome [7:2:1 (+) AmB] formulation, which gave the highest thermal stability, was selected for further skin absorption evaluation.     

A transferrin receptor-targeted liposomal formulation for docetaxel

Transferrin receptor (TfR) is frequently over-expressed on epithelial cancer cells, TfR-targeted liposomes, therefore, can potentially improve tumor cell uptake, cytotoxicity, and treatment efficacy of the encapsulated drug. The liposomes loaded with docetaxel were prepared by polycarbonate membrane extrusion with the composition of hydrogenated soy phosphatidylcholine (HSPC)/egg phosphatidylcholine (PC)/cholesterol (Chol)/methoxy-polyethylene glycol (mPEG)2,000-distearoyl-phosphatidylethanolamine (DSPE) (HSPC/ePC/Chol/mPEG-DSPE) at the ratio of (10:75:10:5, mol/mol) and a drug-to-lipid ratio of 1:20, wt/wt. TfR-targeted liposomes were obtained by a post-insertion method with the ratio of Tf to phospholipid at 1:400 (mol/mol) and then lyophilized with sucrose as a lyoprotectant. TfR-liposomes exhibited enhanced stability for more than 6 months when stored as lyophilized cake. TfR-targeted liposomes of the same lipid composition entrapping calcein showed efficient uptake by K562 cells, which were TfR+. In vitro study of TfR-targeted liposomes containing docetaxel showed 3.6-fold greater cytotoxicity compared to non-targeted control liposomes in KB cells. Compared to docetaxel in Tween 80/ethanol formulation, the liposomal formulations showed much longer terminal half lives (6.37 h and 7.33 h for TfR-targeted and non-targeted, respectively). In conclusion, TfR-targeted liposomes might be a promising targeting delivery vehicle for TfR+ cancers and warrant further investigation.     

Transfersomes--a novel vesicular carrier for enhanced transdermal delivery: development, characterization, and performance evaluation

This work describes the use of a novel vesicular drug carrier system called transfersomes, which is composed of phospholipid, surfactant, and water for enhanced transdermal delivery. The transfersomal system was much more efficient at delivering a low and high molecular weight drug to the skin in terms of quantity and depth. In the present study transfersomes and liposomes were prepared by using dexamethasone as a model drug. The system was evaluated in vitro for vesicle shape and size, entrapment efficiency, degree of deformability, number of vesicles per cubic mm, and drug diffusion across the artificial membrane and rat skin. The effects of surfactant type, composition, charge, and concentration of surfactant were studied. The in vivo performance of selected formulation was evaluated by using a carrageenan-induced rat paw edema model. Fluorescence microscopy by using rhodamine-123 and 6-carboxyfluorescein as fluorescence probe was performed. The stability study was performed at 4°C and 37°C. An in vitro drug release study has shown a nearly zero order release of drug and no lag phase. The absence of lag phase in comparison to liposomes and ointment is attributed to the greater deformability, which may account for better skin permeability of transfersomes. In vivo studies of transfersomes showed better antiedema activity in comparison to liposomes and ointment, indicating better permeation through the penetration barrier of the skin. This was further confirmed through a fluorescence microscopy study. Finally, it may be concluded from the study that complex lipid molecules, transfersomes, can increase the transdermal flux, prolong the release, and improve the site specificity of bioactive molecules.     

Development, characterization and in vitro evaluation of single or co-loaded imatinib mesylate liposomal formulations

Mitoxantrone-based combinations are a standard palliative treatment in hormone-refractory prostate cancer (HRPC) but with no survival benefit. Imatinib has shown preclinical activity against HRPC although minimal clinical therapeutic efficacy. Our previous in vitro studies demonstrated that simultaneous combination of imatinib with mitoxantrone yielded additive growth inhibition effects against PC-3 cell line. The main aim of the work was to develop novel liposomal formulations comprising imatinib co-encapsulated with mitoxantrone, by different loading methods and experimental conditions, in order to achieve the highest drug loading and maximum physical stability. In the optimized formulations, imatinib and mitoxantrone were actively co-loaded by means of a (NH4)2SO4 transmembrane gradient. Encapsulation efficiency, mean size diameter and drug retention in storage and in biological conditions were characterized. Our study presented for the first time an active loading method for imatinib and suggests that the optimized liposomal formulation co-encapsulates both drugs with high encapsulation efficiency (> 95%), shows enhanced drug retention under tested conditions and delivers a drug:drug ratio capable of improving tumor cell growth inhibition with a mitoxantrone dose reduction of 2.6-fold as compared to single liposomal formulation. Therefore, our nanotechnology-based drug combined platform may constitute a promising strategy in prostate cancer therapy.     

Effect of Polycation Complexation on Methotrexate-Liposome Cytotoxicity

Methotrexate and methotrexate-DEAE dextran complex were microencapsulated in positively charged liposomes. Their cytotoxicity was determined and compared with the cytotoxicity of control systems against L1210 mouse leukemia eel Is at 37°C In acetate buffer of pH 7.40 ± 0.05. The control systems used were acetate buffer, blank liposome, DEAE-dextran liposome and methotrexate solution. The methotrexate and methotrexate-DEAE dextran liposomes were lyophilized and the Influence of lyophilization on their cytotoxicity was also examined. The methotrexate-DEAE dextran liposomes resulted in slightly higher mean growth ratios than the free methotrexate liposomes in non lyophilized as well as lyophilized systems. The ED⁵⁰ values for methotrexate and methotrexate-DEAE dextran liposomes were similar to that for the free methotrexate solution. This observation indicated that microencapsulation of methotrexate in liposomes either as a free drug or a complex has no effect on the cytotoxicity of the drug. In addition, lyophilization of liposome products does not seem to change their effectiveness.     

Lyophilization — a Means of Increasing Shelf-Life of Phospholipid Bi-Layer Vesicles

The release rates of sodium stibogluconate were followed in lyophilized and non-lyophilized phospholipid bi-layer vesicles. The release rates were followed under the following environmental temperatures: 4°C, 19°C, 29°C, 35°C, 45°C, 50°C and 55°C. Lyophilization did not significantly effect release rates within temperature groups 4°, 19°, 29°, 35 and 45°C. When the environmental temperature was varied above the tranisition temperature of the dipalmitoyl lecithin, release rates of sodium stibogluconate from lyophilized and non-lyophilized liposomes were found to be independent of temperature.     

Liposomal Encapsulation and Stability of Dideoxyinosine Triphosphate

Dideoxyinosine triphosphate (ddITP) was encapsulated in multilamellar liposomes prepared with various lipid composition. The stability of liposomes in terms of retention of ddITP was measured at 4°, 25° and 37°C. The encapsulation of ddITP was 7.5 times greater in liposomes prepared with dipalmitoylphosphatidylcholine (DPPC) compared to dimyristoylphosphatidyl-choline (DMPC). When equimolar cholesterol (CHOL) was added to DM PC liposomes the encapsulation of ddITP was increased by 4.5 times. The leakage of ddITP was 60% from DMPC liposomes stored at 4° and 25° C after a month and 100% leakage after 16 days when stored at 37° C. The leakage of ddITP from DMPC:CHOL liposomes was only 20% after a month at 4° C, 50% at 25° and 90% at 37° C. These results suggest that the encapsulation of hydrophilic compound such as ddITP can be increased either by increasing the fatty acid chain length (DPPC) or by inclusion of CHOL. However, the optimum encapsulation and retention of ddITP was achieved using DMPC:CHOL liposomes. Retention of ddITP in these liposomes was maximum when stored at 4°c.     

Preparation,Characterization, and Pharmacokinetics of Sterically Stabilized Nimodipine-Containing Liposomes

ABSTRACT

Nimodipine is a dihydropyridine calcium antagonist used in clinical trials in the treatment of ischemic damage in subarachnoid hemorrhage and commercially available as nimotop® intravenous infusion solution and tablets. However, due to its poor solubility in water, intravenous administration depends on the use of the dehydrated alcohol to achieve a clinically relevant concentrated infusion solution while the low bioavailability of the nimotop® tablets were far away from content. We have prepared a well-characterized novel lyophilized liposome-based nimodipine formulation that is sterile and easy-to-use. Of the several formulations examined, nimodipine-liposomes composed of ePC/CHOL 20:3 and co-surfactant poloxamer 188/sodium deoxycholate/ePC/3:0.3:5 were chosen for further studies. This composition was found to give more stable liposomes than other formulations. It gave 89.9% entrapment efficiency and particle size of 200 nm after lyophilization. The pharmacokinetic parameters following orally and intravenously administration to New Zealand rabbits were determined and compared with those of commercial nimodipine formulations. Encapsulation of nimodipine in liposomes produced marked differences over those of commercial preparations with an increased C_max, prolonged elimination half-life, and an increased value for AUC. The obtained values for mean residence time (MRT) indicated that nimodipine remains longer for liposomal formulation. Thus an optimum i.v. liposome formulation for nimodipine can be developed for an alternative to the commercial nimodipine preparations.     

Preparation,in Vitro and in Vivo Evaluation of Liposomal/Niosomal Gel Delivery Systems for Clotrimazole

Clotrimazole, which is an imidazole derivative antifungal agent, was widely used for the treatment of mycotic infections of the genitourinary tract. To develop alternative formulation for the vaginal administration of clotrimazole to provide sustained and controlled release of appropriate drug for local vaginal therapy, liposomes/niosomes were evaluated as delivery vehicles. To optimize the preparation of liposomes/niosomes with regard to size and entrapment efficiency, multilamellar liposomes/niosomes containing drug were prepared by lipid hydration method. The prepared liposomes/niosomes were incorporated into 2% carbopol gel, and the systems were evaluated for drug stability in phosphate-buffered saline (pH 7.4) and simulated vaginal fluid at 37 ± 1°C. Further, the vesicle gel system was evaluated by antifungal activity and tolerability on tissue level in rat.     

Computational design strategy: an approach to enhancing the transdermal delivery of optimal capsaicin-loaded transinvasomes

Abstract

The aim of this study was to design and develop simultaneous optimal transinvasome formulations (OTV) to enhance the transdermal delivery of capsaicin. Using a central composite experimental design with duplicate centroids, 10 model formulations of transinvasomes (TVs) were demonstrated. The lipid compositions of the TV formulations were determined as formulation factors (X_n) and response variables (Y_n), respectively. TV formulations containing a constant concentration of phosphatidylcholine, cholesterol, 0.15% capsaicin, and various percentages of d-limonene (X₁) and cocamide diethanolamine (X₂) were prepared. The physicochemical characteristics, e.g. the vesicle size, size distribution, zeta potential, entrapment efficiency, and skin permeability, of the TV formulations were experimentally investigated. The relationship among the formulation factor, the response variables, and the OTV was predicted using Design Expert^® software. The accuracy and reliability of the OTV predicted using computer software were experimentally confirmed and investigated as an experimental transinvasome formulation (ETV). The results indicated that the skin permeability of the ETV was close to the OTV and was significantly higher than that of conventional liposomes and commercial products. The response surfaces estimated by the computer software were helpful in understanding the complicated relationship among the formulation factor, the response variables, and the stability of the TV formulation.     

Preparation, characterization, and pharmacokinetics of sterically stabilized nimodipine-containing liposomes

Nimodipine is a dihydropyridine calcium antagonist used in clinical trials in the treatment of ischemic damage in subarachnoid hemorrhage and commercially available as nimotop^® intravenous infusion solution and tablets. However, due to its poor solubility in water, intravenous administration depends on the use of the dehydrated alcohol to achieve a clinically relevant concentrated infusion solution while the low bioavailability of the nimotop^® tablets were far away from content. We have prepared a well-characterized novel lyophilized liposome-based nimodipine formulation that is sterile and easy-to-use. Of the several formulations examined, nimodipine-liposomes composed of ePC/CHOL 20:3 and co-surfactant poloxamer 188/sodium deoxycholate/ePC/3:0.3:5 were chosen for further studies. This composition was found to give more stable liposomes than other formulations. It gave 89.9% entrapment efficiency and particle size of 200 nm after lyophilization. The pharmacokinetic parameters following orally and intravenously administration to New Zealand rabbits were determined and compared with those of commercial nimodipine formulations. Encapsulation of nimodipine in liposomes produced marked differences over those of commercial preparations with an increased C_max, prolonged elimination half-life, and an increased value for AUC. The obtained values for mean residence time (MRT) indicated that nimodipine remains longer for liposomal formulation. Thus an optimum i.v. liposome formulation for nimodipine can be developed for an alternative to the commercial nimodipine preparations.     

Physicochemical properties of amphotericin B liposomes prepared by reverse-phase evaporation method

The physicochemical properties of phosphatidylcholine-cholesterol liposomes containing amphotericin B and prepared by reverse-phase evaporation method were studied. Uniformly dispersed liposomal suspensions were obtained by employing 3:1 ratio (by volume) of diethyl ether to normal saline, 5 min sonication time at 7°C, and evaporation of diethyl ether at 25°C. Microscopic examination showed that the prepared liposomes were spheroids with unilamellar, oligolamellar, or multilamellar structure. The liposomes containing amphotericin B 2.0 mol% of total lipid led to the highest percentage of drug entrapment. Liposomes with maximum entrapment efficiency were obtained from using 250 µmol of total lipid. The liposomal amphotericin B possessing the highest drug entrapment efficiency (approximately 95%) with particle size range of 1307-1451 nm was the one composed of 1:1 molar ratio of phosphatidylcholine to cholesterol.     

Development of a Lyophilized Parenteral Pharmaceutical Formulation of the Investigational Polypeptide Marine Anticancer Agent Kahalalide F

Kahalalide F is a novel antitumor agent isolated from the marine mollusk Elysia rufescens; it has shown highly selective in vitro activity against androgen-independent prostate tumors. The purpose of this study was to develop a stable parenteral formulation of kahalalide F to be used in early clinical trials. Solubility and stability of kahalalide F were studied as a function of polysorbate 80 (0.1%-0.5% w/v) and citric acid monohydrate (5-15 mM) concentrations using an experimental design approach. Stabilities of kahalalide F lyophilized products containing crystalline (mannitol) or amorphous (sucrose) bulking agents were studied at +5°C and +30°C ±60% relative humidity (RH) in the dark. Lyophilized products were characterized by infrared (IR) spectroscopy and differential scanning calorimetry (DSC). Recovery studies after reconstitution of kahalalide F lyophilized product and further dilution in infusion fluid were carried out to select an optimal reconstitution vehicle. It was found that a combination of polysorbate 80 and citric acid monohydrate is necessary to solubilize kahalalide F. Lyophilized products were considerably less stable with increasing polysorbate 80 and citric acid monohydrate concentrations, with polysorbate 80 being the major effector. A combination of 0.1% w/v polysorbate 80 and 5 mM citric acid monohydrate was selected for further investigation. Lyophilized products containing sucrose as a bulking agent were more stable compared to the products containing mannitol. The glass transition temperature of the sucrose-based product was determined to be + 46°C. The amorphous state of the product was confirmed by IR analysis. A solution composed of Cremophor EL, ethanol, and water for injection (5%/5%/90% v/v/v CEW) kept kahalalide F in solution after reconstitution and further dilution with 0.9% w/v sodium chloride (normal saline) to 1.5 μg/m. A stable lyophilized formulation was presented containing 100 μg of kahalalide F, 100 mg sucrose, 2.1 mg citric acid monohydrate, and 2 mg polysorbate 80 to be reconstituted with a vehicle composed of 5%/5%/90% v/v/v CEW and to be diluted further using normal saline.     

Preparation, in vitro and in vivo evaluation of liposomal/niosomal gel delivery systems for clotrimazole

Clotrimazole, which is an imidazole derivative antifungal agent, was widely used for the treatment of mycotic infections of the genitourinary tract. To develop alternative formulation for the vaginal administration of clotrimazole to provide sustained and controlled release of appropriate drug for local vaginal therapy, liposomes/niosomes were evaluated as delivery vehicles. To optimize the preparation of liposomes/niosomes with regard to size and entrapment efficiency, multilamellar liposomes/niosomes containing drug were prepared by lipid hydration method. The prepared liposomes/niosomes were incorporated into 2% carbopol gel, and the systems were evaluated for drug stability in phosphate-buffered saline (pH 7.4) and simulated vaginal fluid at 37 +/- 1 degrees C. Further, the vesicle gel system was evaluated by antifungal activity and tolerability on tissue level in rat.     

Preparation of griseofulvin nanoparticle suspension by high-pressure homogenization and preservation of the suspension with saccharides and sugar alcohols

Aim: We have attempted to micronize drug particles with a particle size of less than 100 nm and maintain the particle size of their suspension to improve the solubility and bioavailability of poorly water-soluble drugs. Furthermore, the method of freeze-drying nanoparticles was applied to maintain particulate nature of nanoparticles containing various saccharides and sugar alcohols for a long time. Method: Griseofulvin (GF)–lipid nanoparticle suspension is prepared using GF and a lipid by high-pressure homogenization. The particle size of the obtained GF–lipid nanoparticle suspension is maintained constant by freeze-drying. Result: The mean particle size of GF–lipid nanoparticles prepared by high-pressure homogenization is approximately 60 nm. The mean particle size remains less than 100 nm for 1 month. The GF–lipid nanoparticle suspension containing xylitol, trehalose, or sucrose is freeze-dried to maintain the particulate nature. The mean particle size of the rehydrated suspension is lower than that of the rehydrated suspension containing erythritol or lactose. In particular, it is new knowledge to have found that an aggregation is minimized by adding xylitol which is sugar alcohol. The minimum concentration of xylitol, trehalose, and sucrose required to maintain a constant particle size by rehydration is 3%, 3%, and 5% (w/v), respectively.     

Triptolide loaded solid lipid nanoparticle hydrogel for topical application

Triptolide (TP) has been shown to have anti-inflammatory, antifertility, antineoplastic, and immunosuppressive activity. However, its clinical usage is limited to some extent due to its poor water solubility and toxicity. In order to use innovative ways to administer TP and to overcome or alleviate its disadvantages, controlled-release delivery systems such as solid lipid nanoparticle(SLN(s)) have been developed. In the present paper we describe the preparation and some characterization of specialized delivery systems for TP. The transdermal delivery and anti-inflammatory activity were also evaluated. The results indicated that SLN could serve as an efficient promoter of TP penetrating into skin. Furthermore, different formulations were optimized in this study. The best formulation of SLN, consisted of tristearin glyceride, soybean lecithin, and PEG400MS, with a particle size of 123 ± 0.9 nm, polydispersity index (PI) of 0.19, and zeta potential of - 45 mV. When this SLN dispersion was incorporated into hydrogel, the nanoparticulate structure was maintained, and aggregation and gel phenomena of the particle could be avoided. The cumulative transdermal absorption rate in 12 h was 73.5%, whereas the conventional TP hydrogel was 45.3%. The anti-inflammatory effect is over two-fold higher than that of conventional TP hydrogel. Moreover, this SLN hydrogel consists of pharmaceutically acceptable ingredients, such as soybean lecithin and lipid, and the nanoparticle can improve safety and minimize the toxicity induced by TP.     

In vitro skin permeation and retention of paromomycin from liposomes for topical treatment of the cutaneous leishmaniasis

Paromomycin (PA), a very hydrophilic antibiotic, has been tested as an alternative topical treatment against cutaneous leishmaniasis (CL). Although this treatment has shown promising results, it has not been successful in accelerating the recovery in most cases. This could be attributed to the low skin penetration of PA. Liposomal formulations usually provide sustained and enhanced drug levels in skin. The aim of this study was to prepare liposomal formulations containing PA and to investigate their potential as topical delivery systems of this antileishmanial. Large multilamellar vesicles (MLVs) were prepared by conventional solvent evaporation method. Large unilamellar vesicles (LUVs) were prepared by reverse-phase evaporation method. The lipids used were soybean phosphatidylcholine (PC) and PC:cholesterol (CH) (molar ratio 1:1). The skin permeation experiments across stripped and normal hairless mice skin were performed in modified Franz diffusion cells. The PA entrapment in LUV liposomes (20.4 ± 2.2%) was higher than that observed for MLV liposomes (7.5 ± 0.9%). Drug entrapment was 41.9 ± 6.2% and 27.2 ± 2.4% for PC and PC:CH LUV, respectively. The skin permeation was 1.55 ± 0.31%, 1.29 ± 0.40%, 0.20 ± 0.08%, and 0.50 ± 0.19% for PC LUV, PC:CH LUV, empty LUV + PA and aqueous solution, respectively. Controlled topical delivery, across stripped skin, was observed for PA entrapped in LUV liposomes.     

Liposomes containing drug and cyclodextrin prepared by the one-step spray-drying method

The one-step spray-drying method was applied in the preparation of liposomes containing drug and cyclodextrin (CD). Spray-dried lecithin liposomes, entrapping metronidazole or verapamil alone or together with hydroxypropyl-β-cyclodextrin (HPβCD), were characterized for morphology, size distribution, and drug entrapment efficiency. The main factor influencing the liposomal size was the volume of aqueous medium used for hydration of the spray-dried product. No differences in size or entrapment between liposomes prepared by immediate hydration of dried powder or by hydration after 1 year of powder storage at 4°C were observed. All liposomes were tested for their serum stability. The most stable liposomes (still retaining about 10% of the originally entrapped drug even after 24 hr incubation with serum) were liposomes prepared by the direct spray-drying of the mixture of lipid, drug, and HPβCD.     

Physical characterization and macrophage cell uptake of mannan-coated nanoparticles

Previously, we reported on a cationic nanoparticle-based DNA vaccine delivery system engineered from warm oil-in-water microemulsion precursors. In these present studies, the feasibility of lyophilizing the nanoparticles and their thermal properties were investigated. Also, the binding and uptake of the nanoparticles by a macrophage cell line were studied. The nanoparticles (prior to pDNA coating) were freeze-dried with lactose or sucrose as cryoprotectants. The stability of lyophilized nanoparticles at room temperature was monitored and compared to that of the aqueous nanoparticle suspension. The thermal properties of the nanoparticles were investigated using differential scanning calorimetry (DSC). The nanoparticles, coated or uncoated with mannan as a ligand, were incubated with a mannose receptor positive (MR+) mouse macrophage cell line (J774E), at either 4°C or 37°C to study the binding and uptake of the nanoparticles by the cells. It was found that lactose or sucrose (1-5%, w/v) was required for successful lyophilization of the nanoparticles. After 4 months of storage, the size of lyophilized nanoparticles did not significantly increase while those in aqueous suspension grew by over 900%. Unlike its individual components, emulsifying wax (m.p., ~55°C) and hexadecyltrimethyl ammonium bromide, the nanoparticles showed a melting point of ~90°C. Moreover, the DSC profile of the nanoparticles was different from that of the physical mixture of emulsifying wax and CTAB. After 1 hour incubation at 37°C, the uptake of mannan-coated nanoparticles was 50% higher than that of the uncoated nanoparticles. At 4°C and after one hour, the binding of the mannan-coated nanoparticles by J774E was over 2-fold higher than that of the uncoated nanoparticles. This increase in J774E binding could be abolished by preincubating the cells with free mannan, suggesting that the binding and uptake were receptor-mediated. In conclusion, the nanoparticles were lyophilizable, and lyophilization was shown to enhance the stability of the nanoparticles. DSC provided evidence that the nanoparticles were not a physical mixture of their individual components. Finally, cell binding and uptake studies demonstrated that the nanoparticles have potential application for cell-specific targeting.