Pulmonary Delivery of Triptorelin Loaded in Pluronic Based Nanomicelles in Rat Model

INTRODUCTION

Triptorelin, the synthetic analog of gonadotrophin-releasing hormone, is used for the treatment of sex hormone dependent diseases via parenteral administration. The aim of the present study was to investigate the possibility of triptorelin pulmonary delivery and preparation of a pulmonary nanocarrier delivery system for it.

METHODS

Triptorelin was loaded in Pluronic-F127 grafted poly (methyl vinyl ether-alt-maleic acid) nanomicelles by direct dissolution method. Effects of the processing variables including: drug/polymer ratio, temperature, stirring rate and time on the physicochemical properties of nanomicelles including zeta potential, particle size, drug entrapment efficiency and release profiles of triptorelin loaded nanomicelles were evaluated. For animal studies 24 Wistar rats were separated into four groups of six. Group 1 received blank nanomicelles, groups 2, 3 and 4 were treated with a single dose of 250 µg.kg-1 of triptorelin solution subcutaneously (sc), pulmonary spraying of triptorelin solution (250 µg.kg-1) and pulmonary spraying of triptorelin nanomicelles (250 µg.kg-1), respectively by microsprayer.

RESULTS

The optimized micelles had particle size of 87.35 nm, zeta potential of -12.8 mV, entrapment efficiency of 84.36% and release efficiency of 65%. The area under the blood testosterone levels increment differed significantly (p<0.05) between pulmonary triptorelin nanomicelles and drug solution. The pharmacological activity of the simple solution was 59.38%, while it was 80.18% for the nanomicelles relative to sc route of administration with prolonged residence time.

CONCLUSION

The results of this study show that not only triptorelin is absorbable from the lungs but also nanomicelles can significantly enhance its pulmonary absorption compared to its simple solution.

Preparation and Evaluation of Lipid-Based Liquid Crystalline Formulation of Fenofibrate

BACKGROUND

Many drugs have poor water solubility and so the oral delivery of such drugs is usually associated with limitation of low bioavailability and lack of dose proportionality. Lipid-based liquid crystal (LC) systems are excellent potential formulations for increasing dissolution and bioavailability of drugs. The aim of the present study was to formulate lipid-based LC containing fenofibrate (FFB) as a hydrophobic drug.

MATERIALS AND METHODS

The studied variables included lipid and stabilizer concentrations and the type of stabilizer. The LC formation was identified by the polarized optical microscopic method. The effects of variables on formulation characteristics such as particle size, drug release, and rheological behavior were evaluated.

RESULTS

The results showed that the prepared formulations had the particle size between 42 and 503 nm. The drug release profiles showed that FFB had the continuous release from the formulations and the highest dissolution efficiency was seen in formulation prepared by 1.5% of glyceryl monostearate and 0.5% of Pluronic F127 as the stabilizer. The change of stabilizer type from colloidal silica to Pluronic F127 increased the drug release, significantly.

CONCLUSIONS

In the most formulations of FFB LCs, the DE% was more than the pure drug, and therefore, it seems that the liquid crystalline formulations can be effective for enhancing drug release. Furthermore, drug release rate depended on the stabilizer type so that the presence of colloidal silica caused slower drug release compared to Pluronic F127.

Folic acid Targeted Polymeric Micelles Based on Tocopherol Succinate- Pulluan as an Effective Carrier for Epirubicin: Preparation, Characterization and In-vitro Cytotoxicity Assessment

BACKGROUND

Chemotherapy still encounters a serious drawback, the lack of selectivity of anticancer drugs toward neoplastic cells, thus, the normal cells are affected by the cytotoxic action of the drugs. This causes a narrow therapeutic index in most anticancer drugs.

OBJECTIVE

We describe the preparation of pullulan-tocopherol succinate-folic acid (Pu-TS-FA) micelles for the first time to targeted delivery of Epirubicin (EPI) to Hela and MCF-7 cell lines.

METHODS

We confirmed the structure of conjugate using spectroscopic methods. The degree of substitution for both folic acid and tocopherol succinate was calculated using 1HNMR. We prepared the micelles via direct dissolution method. All the physicochemical properties of micelles including size, zeta potential, polydispersity index (PDI), critical micelle concentration (CMC), entrapment efficiency (EE %) and release efficiency (RE24%) were determined. The morphology of particles was studied using transmission electron microscopy (TEM), and the in-vitro cell cytotoxicity of EPI loaded micelles was studied using MTT assay on MCF-7 and Hela cell lines.

RESULTS

The optimized micelles showed the particle size of 149.5 nm, the zeta potential of -6.49 mV, a polydispersity index of 0.259 ± 0.07, LE% of 88 %, and RE24% of 63 ± 2.45 % with a relatively low CMC 194.87 µg/ml. TEM showed the relatively uniform spherical structure for particles and in vitro MTT assay showed that EPI loaded micelles were more toxic on Hela cell line than MCF7 as expected.

CONCLUSION

Since the Pu-TS-FA micelle could improve the anticancer activity of epirubicin and would be a promising candidate for EPI treatment of cancers.

Preparation and in vitro evaluation of novel cross-linked chondroitin sulphate nanoparticles by aluminium ions for encapsulation of green tea flavonoids

Chondroitin sulphate is a sulphated glycosaminoglycan biopolymer composed over 100 individual sugars. Chondroitin sulphate nanoparticles (NPs) loaded with catechin were prepared by an ionic gelation method using AlCl₃ and optimised for polymer and cross-linking agent concentration, curing time and stirring speed. Zeta potential, particle size, loading efficiency, and release efficiency over 24 h (RE₂₄%) were evaluated. The surface morphology of NPs was investigated by scanning electron microscopy and their thermal behaviour by differential scanning calorimetric. Antioxidant effect of NPs was determined by chelating activity of iron ions. The cell viability of mesenchymal stem cells was determined by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide assay and the calcification of osteoblasts was studied by Alizarin red staining. The optimised NPs showed particle size of 176 nm, zeta potential of -20.8 mV, loading efficiency of 93.3% and RE₂₄% of 80.6%. The chatechin loaded chondroitin sulphate NPs showed 70-fold more antioxidant activity, 3-fold proliferation effect and higher calcium precipitation in osteoblasts than free catechin.

Solubility Enhancement of Domperidone by Solvent Change In situ Micronization Technique

Background:

Domperidone (DOM), a dopamine receptor antagonist, is used as antiemetic for the treatment of gastroparesis, vomiting, and nausea. The low water solubility of DOM leads to a low dissolution rate and variable bioavailability. The aim of this study was to enhance the solubility of DOM by the preparation of micron-sized particles.

Materials and Methods:

The in situ micronization process was carried out using solvent change method in the presence of Soluplus^® or PEG₆₀₀₀ as stabilizing agents. DOM was dissolved in appropriate solvent (acetone and methanol 1:1 v/v), and the stabilizing agent was dissolved in water (as nonsolvent). The nonsolvent was poured rapidly into the drug solution under stirring by a homogenizer, and the resultant was freeze dried. The crystalline shape and particle size of DOM and interaction of DOM with stabilizers were investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC), and then, dissolution test was carried out.

Results:

Optimum formulation was composed of DOM (0.5%) and PEG₆₀₀₀ (0.1%) with the lowest particle size (3 μm) and the highest DE_60% (95.95%) as compared to pure DOM (particle size of 13.4 μm and DE_60% 52.18%).

Conclusion:

SEM micrographs showed uniform and spherical shape of microcrystals. FTIR, XRD, and DSC studies indicated the micron size of the microcrystals and no interference between the drug and the stabilizer.

Solid Dispersion of Hesperetin Co-crystals Synergistically Attenuates Hepatic Toxicity of Carbon Tetrachloride Oxidative Stress in Rats

BACKGROUND

Hesperetin (HSP) is a low water-soluble flavanone aglycone with low bioavailability.

OBJECTIVES

This study aimed at enhancing the hepatoprotective effects of HSP by a combinatory technique based on solid dispersions of co-crystals of HSP.

METHODS

Co-crystals were prepared using citric acid, tartaric acid, caffeine and isonicotinamide (INM) using two methods of solvent evaporation and co-grinding. The solid dispersion of co-crystals with different ratio of INM, PVP K30 and drug was prepared by the solvent evaporation method. The resulting material was characterized by DSC, XRD, FTIR and SEM, their saturated solubility and dissolution rate were compared to the pure drug. Finally, liver toxicity was induced in rats by carbon tetrachloride (CCl4) and mice were treated with different formulations of HSP. The liver function was tested by measurement of glutamate pyruvate transaminase (SGPT), glutamate oxaloacetate transaminase (SGOT), serum alkaline phosphatase (ALP) and bilirubin as well as histopathological tests.

RESULTS

Although saturation solubility of HSP was enhanced about 5 times by co-crystals of HSP/INM (1:2), solid dispersions of the co-crystals of HSP obtained from PVP K30 and INM enhanced it up to 200 folds. Functional parameters of liver in rats pretreated with a solid dispersion of co-crystals of HSP were significantly lower than those with pure HSP and co-crystals of INM/HSP with 2:1 ratio. Furthermore, this formulations reduced liver damage effectively compared with the CCL4 group.

CONCLUSION

Solid dispersion of HSP co-crystals synergistically attenuates hepatic toxicity of carbon tetrachloride oxidative stress in rats more effectively than its solid dispersions or co-crystals alone.

Immobilization of lactoperoxidase on graphene oxide nanosheets with improved activity and stability

OBJECTIVES

The purpose of this study was to develop a facile and efficient method to enhance the stability and activity of lactoperoxidase (LPO) by using its immobilization on graphene oxide nanosheets (GO-NS).

METHODS

Following the LPO purification from bovine whey, it was immobilized onto functionalized GO-NS using glutaraldehyde as cross-linker. Kinetic properties and stability of free and immobilized LPO were investigated.

RESULTS

LPO was purified 59.13 fold with a specific activity of 5.78 U/mg protein. The successful immobilization of LPO on functionalized GO-NS was confirmed by using dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR). The overall results showed that the stability of the immobilized LPO was considerably improved compared to free LPO. Apparent K_m and V_max of LPO also indicated that the immobilized enzyme had greater affinity to the substrate than the native enzyme.

CONCLUSIONS

Graphene oxide nanosheets are effective means for immobilization of LPO.

Development of a Rapid and Precise Reversed-phase High-performance Liquid Chromatography Method for Analysis of Docetaxel in Rat Plasma: Application in Single-dose Pharmacokinetic Studies of Folate-targeted Micelles Containing Docetaxel

Background:

A simple and sensitive reversed-phase high-performance liquid chromatography (HPLC) method based on liquid-liquid extraction was established and validated for determination of docetaxel (DTX) in plasma of rat.

Materials and Methods:

Samples were spiked with paclitaxel as the internal standard and the chromatographic separation was carried out using C18 HPLC column. The mobile phase consisted of a mixture of acetonitrile/water with the ratio of 60/40 v/v. The ultraviolet detector was operated at 230 nm, and the flow rate of mobile phase was 1 ml/min. The method was validated for linearity, precision, accuracy, recovery, and limit of quantification (LOQ). Then the method was applied to quantify DTX in the rat plasma after intravenous (IV) administration of the self-assembled micelles of folate-targeted Synpronic F127/cholesterol (FA-PF127-Chol) loaded with DTX and Taxotere^® as the reference marketed solution of DTX. The blood samples were taken from the ophthalmic vein at predetermined time intervals after treatment.

Results:

Calibration curve was linear between the concentration ranges of 0.1–7.5 μg/ml with the relative standard deviation % and evaluating error % ranged from 2.263 to 15.53 and −12.75 to 12.7 for intra- and inter-day validity, respectively. The mean recovery of the drug after plasma extraction was 95.67 ± 0.99% for the concentration of 1 μg/ml. The LOQ and the limit of detection for DTX in serum were 100 ng/ml and 30 ng/ml, respectively.

Conclusions:

The results indicated that the developed method could be adopted for pharmacokinetic studies of DTX-loaded FA-PF127-Chol micelles and Taxotere^® in rat.

Optimization of Poly(methyl vinyl ether-co-maleic acid) Electrospun Nanofibers as a Fast-Dissolving Drug Delivery System

Background:

Poly(methyl vinyl ether-maleic acid) (PMVEMA) is a water-soluble, biodegradable polymer used for drug delivery. The aim of the present study was to prepare nanofibers of this polymer as a fast-dissolving carrier for montelukast.

Materials and Methods:

Polymeric nanofibers were spun by electrospinning method using different ratios of biodegradable polymer of PMVEMA. The processing variables including voltage, distance of the needle to rotating screen, and flow rate of the solution were optimized based on the diameter of the nanofibers, drug content, and release efficiency by a Taguchi design. The morphology, diameter, and diameter distribution of the nanofibers were studied by scanning electron microscopy (SEM). Drug loading and its release rate from the nanofibers were analyzed spectrophotometrically. The possible molecular between the polymer and the drug was characterized with Fourier-transform-infrared spectroscopy.

Results:

The results showed the best situation for electrospinning of the polymer obtained at the polymer concentration of 37%, the distance of the needle to rotating screen of 19 cm, the voltage of 120 kV, and the rate of injection of 0.2 ml/h. In these situations, the fiber diameter and drug loading efficiency percentage were 273 nm and 83%, respectively. These nanofibers released the total loaded drug within 1–3 s with no residue in the dissolution medium. SEM results showed that the optimized nanofibers were quite smooth and without beads.

Conclusions:

The results indicated that the nanofibers of PMVEMA could dissolve the drug very rapidly and can be adopted for fast-dissolving dosage forms.

Recent approaches for targeted drug delivery in rheumatoid arthritis diagnosis and treatment

Rheumatoid arthritis (RA) is a chronic inflammatory disease with complex pathology characterized by inflammation of joints, devastation of the synovium, pannus formation, bones and cartilage destruction and often is associated with persistent arthritic pain, swelling, stiffness and work disability. In conventional RA therapy, because of short biological half-life, poor bioavailability, high and frequent dosing is required. Thereby, these anti-RA medications, which unable to selectively target affected zone, may cause severe side effects in extra-articular tissues. Today, nanotechnology has emerged as promising tool in the development of novel drug delivery systems for the treatment and diagnosis of intractable diseases such as RA. Active targeting in RA nanomedicine has also been introduced a successful way for facilitating specific uptake of therapeutic agents by the disease cells. In this review, it is attempted to describe various targeted drug delivery systems (localized and receptor-based) used for RA diagnosis and therapy. Then, we highlight recent developments related to various non-viral gene delivery systems for RA gene therapy.

Nanocrystalization of Pioglitazone by Precipitation Method

BACKGROUND

Poor solubility in aqueous medium limits the use of many drugs. Different methods have been adopted to promote the rate of dissolution of slightly water soluble drugs. Crystallization improves solubility, and bioavailability by increasing the surface area of slightly water soluble drugs. Pioglitazone (PGZ), which is a class II Biopharmaceutical Classification System drug has a slight solubility in water and a slow rate of dissolution, which may have a negative effect on its metabolism leading to a therapeutic failure.

AIM

The aim of this study was to improve the solubility of PGZ-HCl; an antidiabetic drug using precipitation method.

MATERIALS AND METHODS

Formulations were prepared with polyethylene glycol 6000 and isomalt using different speed of homogenizer and quantity of solvent by precipitation method. Drug-polymer interactions were examined using differential scanning calorimetry (DSC), and Powder X-Ray Diffraction (PXRD). Surface structure were shown by SEM photographs.

RESULTS

The particle size was significantly decreased and solubility was enhanced with increase speed, ethanol solvent and increase stabilizer, however very high amount of stabilizer resulted in a decrease in solubility.

CONCLUSION

This result however showed that solid dispersion technique is a potential method for increasing dissolution profile of a poorly aqueous soluble agent.

Synthesis, in vitro characterization, and anti-tumor effects of novel polystyrene-poly(amide-ether-ester-imide) co-polymeric micelles for delivery of docetaxel in breast cancer in Balb/C mice

OBJECTIVE

The goal of the present work was to make novel co-polymeric micellar carriers for the delivery of docetaxel (DTX).

SIGNIFICANCE

Co-polymeric micelles can not only solubilize DTX and eliminate the need for toxic surfactants to dissolve it, but also cause passive targeting of the drug to the tumor and reduce its toxic side effects.

METHODS

Poly(styrene-maleic acid) (SMA) was conjugated to poly (amide-ether-ester-imide)-poly ethylene glycol (PAEEI-PEG). Copolymer synthesis was proven by Fourier transform infrared (FTIR) and ¹H-nuclear magnetic resonance (¹H-NMR). The SMA-PAEEI-PEG micelles loaded with DTX were prepared and their critical micelle concentration (CMC), zeta potential, particle size, entrapment efficiency, and their release efficiency were studied. MCF-7 and MDA-MB231 breast cancer cells were used to evaluate the cellular uptake and cytotoxicity of the micelles. The antitumor activity of the DTX-loaded nanomicelles was measured in Balb/c mice.

RESULTS

The FTIR and HNMR spectroscopy confirmed successful conjugation of SMA and PAEEI-PEG. The drug loading efficiency was in the range of 34.01-72.75% and drug release lasted for 120 h. The CMC value of the micelles was affected by the SMA/PAEEI-PEG ratio and was in the range of 29.85-14.28 µg/ml. The DTX-loaded micelles showed five times more cytotoxicity than the free drug. The DTX loaded micelles were more effective in tumor growth suppression in vivo and the animals showed an enhanced rate of survival.

CONCLUSION

The results show that the SMA-PAEEI-PEG micelles of DTX could potentially provide a suitable parenteral formulation with more stability, higher cytotoxicity, and improved antitumor activity.

Enhancement in Biological Activity of L-Asparginase by its Conjugation on Silica Nanoparticles

BACKGROUND

L-asparaginase is a drug of choice in the treatment of Hodgkin's lymphoma and acute lymphoblastic leukemia. Production of its bioconjugates can increase its half-life, stability and decrease its immunogenicity.

OBJECTIVE

The aim of the present study was to immobilize this drug on silica nanoparticles by two different cross-linking agents.

METHOD

The drug was conjugated to nanoparticles by two cross-linking agents; 1-ethyl-3-(3- dimethylaminopropyl) carboiimide HCl (EDC) or glutaraldehyde. The effect of the drug to the nanoparticles ratio, the amount of cross-linking agents and the time of conjugation were optimized according to the zeta potential, size particle and the enzyme immobilization efficiency. Conjugation of L-asparaginase to nanoparticles was confirmed by FT-IR and TEM. The activity, kinetic profiles, stability against pH changes, thermal and storage stability of the native and immobilized drug were compared.

RESULTS

The results showed significant increase in pH range of the stability and decrease in the km value of the drug after immobilization; indicating an increase in the enzyme tendency for the substrate. The Time of stability of the drug increased after immobilization in plasma and phosphate buffer saline which can increase its half-life of circulation.

CONCLUSION

The activity and stability of immobilized drug by EDC were better than glutaraldehyde.

Enhanced solubility, oral bioavailability and anti-osteoporotic effects of raloxifene HCl in ovariectomized rats by Igepal CO-890 nanomicelles

The purpose of the present study was to enhance the bioavailability and anti-osteoporotic effects of raloxifene HCl (RH) by increasing its solubility and inhibition of the p-glycoprotein pump using surfactant micelles of Igepal CO-890. The micelles were prepared by the direct method and their critical micellar concentration, drug dissolution rate, saturated solubility, drug loading and surface morphology were defined. The cytotoxicity of Igepal CO-890 and its ability to inhibit the p-glycoprotein pump were studied on Caco-2 cells. The pharmacokinetic parameters were analyzed by oral administration of a single dose of 15 mg/kg in Wistar rats. Anti-osteoporotic effects were studied by measuring the calcium, phosphorous, and uterus weight of rats after one month of oral administration of 6 mg/kg/day of RH in ovariectomized rats. Igepal CO-890 micelles enhanced the RH solubility by about two-fold. The FT-IR and DSC studies indicated no interaction between the drug and the surfactant. XRD spectrum showed an amorphous state of RH in the micelles. The p-glycoprotein pump was inhibited by Igepal CO-890 in Caco-2 cells comparable to verapamil. Micelles increased the uterine weight and decreased the serum calcium and phosphorus significantly compared to the untreated drug. Oral bioavailability of RH increased about four-fold by nanomicelles.

Pharmacokinetics and in vitro/in vivo antitumor efficacy of aptamer-targeted Ecoflex® nanoparticles for docetaxel delivery in ovarian cancer

Purpose

Epithelixal ovarian cancer is the fourth cause of cancer death in developed countries with 77% of ovarian cancer cases diagnosed with regional or distant metastasis, with poor survival rates. Docetaxel (DTX) is a well-known anticancer agent, with clinically proven efficacy in several malignancies, including ovarian cancer. However, the adverse effects caused by the active ingredient or currently marketed formulations could even deprive the patient of the advantages of treatment. Therefore, in the current study, polymeric nanoparticles (NPs) equipped with aptamer molecules as targeting agents were proposed to minimize the adverse effects and enhance the antitumor efficacy through directing the drug cargo toward its site of action.

Materials and methods

Electrospraying technique was implemented to fabricate poly (butylene adipate-co-butylene terephthalate) (Ecoflex^®) NPs loaded with DTX (DTX-NPs). Afterward, aptamer molecules were added to the DTX-NPs, which bound via covalent bonds (Apt-DTX-NPs). The particle size, size distribution, zeta potential, entrapment efficiency, and release profile of the NPs were characterized. Using MTT assay and flow-cytometry analysis, the in vitro cytotoxicity and cellular uptake of the NPs were compared to those of the free drug. Following intravenous administration of Taxotere^®, DTX-NPs, and Apt-DTX-NPs (at an equivalent dose of 5 mg/kg of DTX), pharmacokinetic parameters and antitumor efficacy were compared in female Balb/c and HER-2-overexpressing tumor-bearing B6 athymic mice, respectively.

Results

The obtained results demonstrated significantly enhanced in vitro cytotoxicity and cellular uptake of Apt-DTX-NPs in a HER-2-overexpressing cell line, comparing to DTX-NPs and the free drug. The results of in vivo studies indicated significant increment in pharmacokinetic parameters including the area under the plasma concentration–time curve, mean residence time, and elimination half-life. Significant increment in antitumor efficacy was also observed, probably due to the targeted delivery of DTX to the tumor site and enhanced cellular uptake as evaluated in the aforementioned tests.

Conclusion

Hence, the proposed drug delivery system could be considered as an appropriate potential substitute for currently marketed DTX formulations.

Poly(methyl vinyl ether-co-maleic acid) for enhancement of solubility, oral bioavailability and anti-osteoporotic effects of raloxifene hydrochloride

Raloxifene HCl (RH) has poor water solubility and due to its extensive first pass metabolism; its bioavailability is only 2%. The purpose of the present study was to enhance the aqueous solubility, oral bioavailability and anti-osteoporotic effects of RH by electro-sprayed nanoparticles (NPs) in ovariectomized rats. NPs containing RH and different ratio of poly(methyl vinyl ether-co-maleic acid) (PMVEMA) were electrosprayed. The voltage, distance of needle to the collector, flow rate of the solution and polymeric percentage were optimized according to the size of NPs and drug solubility. The optimized formulation was characterized by SEM, XRD, DSC, and FTIR. The pharmacokinetic parameters were studies by oral administration of a single dose of 15mg/kg in Wistar rats. The anti-osteoporotic effects were studied in female ovariectomized rats. Animals were treated with 6mg/kg/day for 2months then serum calcium, phosphorous and alkaline phosphatase levels were measured. RH loaded electrosprayed NPs showed 10-fold enhanced solubility compared to the free drug. Moreover, the XRD and SEM tests displayed an amorphous state of drug in the NPs. FTIR and DSC tests revealed no interaction between the polymer and the drug. Serum calcium, phosphorous and alkaline phosphatase levels were significantly decreased in ovariectomized rats receiving oral RH NPs (P<0.05). No significant difference was detected between RH NPs and estradiol groups (P>0.05). Oral bioavailability of NPs showed 7.5-fold increase compared to the pure drug. The electrosprayed PMVEMA nanoparticles can enhance solubility, bioavailability and antiosteoporotic effects of RH.