Development of self-microemulsifying drug delivery system for oral bioavailability enhancement of berberine hydrochloride

Development and evaluation of vitamin E d-α-tocopheryl polyethylene glycol 1000 succinate-mixed polymeric phospholipid micelles of berberine as an anticancer nanopharmaceutical

Berberine (Brb) is an active alkaloid occurring in various common plant species, with well-recognized potential for cancer therapy. Brb not only augments the efficacy of antineoplastic chemotherapy and radiotherapy but also exhibits direct antimitotic and proapoptotic actions, along with distinct antiangiogenic and antimetastatic activities in a variety of tumors. Despite its low systemic toxicity, several pharmaceutical challenges limit the application of Brb in cancer therapy (ie, extremely low solubility and permeability, very poor pharmacokinetics (PKs), and oral bioavailability). Among lipid-based nanocarriers investigated recently for Brb, stealth amphiphilic micelles of polymeric phospholipid conjugates were studied here as a promising strategy to improve Brb delivery to tumors. Specifically, physicochemically stable micelles made of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)-2000] (PEG-PE) mixed with d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) (PEG-succinate ester of vitamin E), in a 3:1 M ratio, increased Brb solubilization by 300%. Our PEG-PE/TPGS-mixed micelles firmly retained the incorporated Brb, displaying extended-release profile in simulated media, with up to 30-fold projected improvement in simulated PKs of Brb. Owing to the markedly better uptake of Brb-containing mixed micelles in vitro, our Brb-mixed micelles nanoformulation significantly amplified apoptosis and overall cytotoxic effectiveness against monolayer and spheroid cultures of human prostate carcinomas (16- to 18-fold lower half-maximal inhibitory concentration values in PC3 and LNPaC, respectively), compared to free Brb. Mixed PEG-PE/TPGS micelles represent a promising delivery platform for the sparingly soluble anticancer agent, Brb, encouraging further pharmaceutical development of this drug for cancer therapy.

Mixed surfactant based (SNEDDS) self-nanoemulsifying drug delivery system presenting efavirenz for enhancement of oral bioavailability

This study aims to develop a self-nanoemulsifying drug delivery system (SNEDDS) based on non-ionic surfactant mixtures to improve the oral bioavailability of efavirenz (EFZ) categorized as a class II according to the BCS, for HIV- therapy. The result of solubility studies of EFZ in various excipients utilized for construction of the pseudo ternary phase diagram containing surfactant mixtures. Surfactants in 1:1 combination are used with different co-surfactants in different ratio to delineate the area of monophasic region of the pseudo ternary phase diagram. Different accelerated physical stability studies and self-emulsification assessment were performed on the formulations. The formulations clearing the above studies are considered for percentage transmittance and turbidity analysis. The globule size distributions of post diluted SNEDDS having percentage transmittance above 90 were estimated. The TEM analysis of two optimized post diluted SNEDDS formulations further confirm the size in nanometric range (below 50nm). FT-IR studies showed the retention of the characteristic peaks of EFZ in the preconcentrate. The in vitro dissolution profile of SNEDDS established advantages of SNEDDS over plain drug as more than 80% drug was released within 30min in case of optimized SNEDDS while it was approximately 18.3% in the case of plain drug powder. Pharmacokinetic parameters were calculated after performing the in vivo studies of best optimized formulation in rats. The Pharmacokinetic data reveal a 2.63 fold increase in AUC(0-∞) in comparison to plain EFZ suspension. The designed delivery system showed the faith in generating an effective formulation of EFZ for HIV treatment.

Development of Bioadhesive Microspheres for Oral Bioavailability Enhancement of Berberine Hydrochloride

The objective of this study was to innovatively prepare chitosan-coated alginate/gelatin BBH loaded microspheres and evaluate their pharmaceutical characteristics and pharmacokinetics. The bioadhesive microspheres were prepared using an emulsification technique. Three batches of microspheres were formed and their stability was evaluated. BBH loaded microspheres were almost spherical with shallow elevation on surfaces. The mean particle size of microspheres was 368.2 μm, drug loading was3.59±0.01%, andin situbioadhesion percentage was91.23%±8.2%and they achieved a sustained release with 71.29% for 8 hoursin vitro. Pharmacokinetic studies in rats indicated that the bioavailability of BBH microspheres was enhanced about 1.5-fold as compared with commercial tablets. BBH microspheres exhibited a sustained-release profile over 48 h. Thus, chitosan-coated alginate/gelatin BBH loaded microspheres which combined the advantages of alginate/gelatin microspheres and chitosan may be used as a sustained delivery system for BBH to treat duodenal and benign gastric ulcers.

Nanocarriers for the delivery of active ingredients and fractions extracted from natural products used in traditional Chinese medicine (TCM)

Traditional Chinese medicine (TCM) has been practiced for thousands of years with a recent increase in popularity. Despite promising biological activities of active ingredients and fractions from TCM, their poor solubility, poor stability, short biological half-life, ease of metabolism and rapid elimination hinder their clinical application. Therefore, overcoming these problems to improve the therapeutic efficacy of TCM preparations is a major focus of pharmaceutical sciences. Recently, nanocarriers have drawn increasing attention for their excellent and efficient delivery of active TCM ingredients or fractions. This review discusses problems in the delivery of active TCM ingredients or fractions; focuses on recent advances in nanocarriers that represent potential solutions to these problems, including lipid-based nanoparticles and polymeric, inorganic, and hybrid nanocarriers; and discusses unanswered questions in the field and criteria for the development of better nanocarriers for the delivery of active TCM ingredients or fractions to be focused on in future studies.

Curcumin-piperine mixtures in self-microemulsifying drug delivery system for ulcerative colitis therapy

Curcumin (CUR) is a poorly water-soluble drug and its absorption is very low. In this study, CUR and piperine (PIP) were co-encapsulated into the nanoformulation called self-microemulsifying drug delivery system (SMEDDS) to improve the stability and water-solubility of CUR and enhance its anti-colitis activity. The formulation of CUR-PIP-SMEDDS was prepared to encapsulate two hydrophobic components CUR and PIP, and then was characterized by assessing appearance, morphology, particle size, zeta potential and drug encapsulation efficiency. The appearance of CUR-PIP-SMEDDS remained clarified and transparent, and the microemulsion droplets appeared spherical without aggregation. The mean size of microemulsion droplet formed from CUR-PIP-SMEDDS was 15.87 ± 0.76 nm, and the drug encapsulation efficiency of SMEDDS for CUR and PIP were (94.34 ± 2.18)% and (90.78 ± 2.56)%, respectively. The vitro stability investigation of CUR-PIP-SMEDDS in colon tissue suggested that using SMEDDS as a delivery vehicle and co-encapsulated with PIP, CUR was more stable than drug solution in colons site. Meanwhile, the anti-inflammatory activity of CUR-PIP-SMEDDS was evaluated on DSS-induced colitis model. The results showed that CUR-PIP-SMEDDS exhibited definite anti-colitis activity by directing CUR-PIP-SMEDDS to inflammatory colon tissue through retention enema administration. Our study illustrated that the developed CUR-PIP-SMEDDS formulation was a potential carrier for developing colon-specific drug delivery system of CUR for ulcerative colitis treatment.

Self-nanoemulsifying drug delivery systems ameliorate the oral delivery of silymarin in rats with Roux-en-Y gastric bypass surgery

Roux-en-Y gastric bypass (RYGB) is a popular surgery to reduce the body weight of obese patients. Although food intake is restricted by RYGB, drug absorption is also decreased. The purpose of this study was to develop novel self-nanoemulsifying drug delivery systems (SNEDDS) for enhancing the oral delivery of silymarin, which has poor water solubility. The SNEDDS were characterized by size, zeta potential, droplet number, and morphology. A technique of RYGB was performed in Sprague-Dawley rats. SNEDDS were administered at a silymarin dose of 600 mg/kg in normal and RYGB rats for comparison with silymarin aqueous suspension and polyethylene glycol (PEG) 400 solution. Plasma silibinin, the main active ingredient in silymarin, was chosen for estimating the pharmacokinetic parameters. SNEDDS diluted in simulated gastric fluid exhibited a droplet size of 190 nm with a spherical shape. The nanocarriers promoted silibinin availability via oral ingestion in RYGB rats by 2.5-fold and 1.5-fold compared to the suspension and PEG 400 solution, respectively. A significant double-peak concentration of silibinin was detected for RYGB rats receiving SNEDDS. Fluorescence imaging showed a deeper and broader penetration of Nile red, the fluorescence dye, into the gastrointestinal mucosa from SNEDDS than from PEG 400 solution. Histological examination showed that SNEDDS caused more minor inflammation at the gastrointestinal membrane as compared with that caused by PEG 400 solution, indicating a shielding of direct silymarin contact with the mucosa by the nanodroplets. SNEDDS generally showed low-level or negligible irritation in the gastrointestinal tract. Silymarin-loaded SNEDDS were successfully developed to improve the dissolution, permeability, and oral bioavailability of silymarin. To the best of our knowledge, this is the first investigation reporting the usefulness of SNEDDS for improving drug malabsorption elicited by gastric bypass surgery.

Berberine nanosuspension enhances hypoglycemic efficacy on streptozotocin induced diabetic C57BL/6 mice

Berberine (Ber), an isoquinoline derivative alkaloid and active ingredient of Coptis, has been demonstrated to possess antidiabetic activities. However its low oral bioavailability restricts its clinical application. In this report, Ber nanosuspension (Ber-NS) composed of Ber and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) was prepared by high pressure homogenization technique. Antidiabetic effects of Ber-NS relative to efficacy of bulk Ber were evaluated in streptozotocin (STZ) induced diabetic C57BL/6 mice. The particle size and zeta potential of Ber-NS were 73.1 ± 3.7 nm and 6.99 ± 0.17 mV, respectively. Ber-NS (50 mg/kg) treatment via oral gavage for 8 weeks resulted in a superior hypoglycemic and total cholesterol (TC) and body weight reduction effects compared to an equivalent dose of bulk Ber and metformin (Met, 300 mg/kg). These data indicate that a low dosage Ber-NS decreases blood glucose and improves lipid metabolism in type 2 diabetic C57BL/6 mice. These results suggest that the delivery of Ber as a nanosuspension is a promising approach for treating type 2 diabetes.

Nanocomplexes based on amphiphilic hyaluronic acid derivative and polyethylene glycol-lipid for ginsenoside rg3 delivery

Hybrid nanocomplex formulations, based on amphiphilic hyaluronic acid-ceramide (HACE) and lipids, were fabricated for the delivery of 20(S)-ginsenoside Rg 3 [(S)-Rg3]. Nanocomplexes with less than 200 nm mean diameter, narrow size distribution, spherical shape, and negative zeta potential were prepared. The maintenance of the structural stability of the hybrid nanocomplexes in the blood stream was demonstrated by measuring their particle size in serum. Nanocomplexes based on HACE, phosphatidylcholine (PC), and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)-2000] (DSPE-PEG) showed a sustained drug release profile compared with other formulations. Blank nanocomplexes exhibited negligible cytotoxicity within the tested concentration range in A549 human lung adenocarcinoma cells. The cellular uptake efficiency of hybrid nanocomplexes was improved compared with the HACE-based nanoparticles probably because of interactions between lipids and the cellular membrane. The results of a pharmacokinetic study in rats revealed decreased in vivo clearance of (S)-Rg3, especially in the HACE/PC/DSPE-PEG-based hybrid nanocomplex (F3) group. The hybrid nanostructure and the outer PEG chain likely contributed to improve in vivo performance of the F3 group. Thus, these developed hybrid nanocomplexes could serve as good candidates for tumor-targeted delivery of anticancer agents.

Improvement of anti-inflammatory and anti-angiogenic activity of berberine by novel rapid dissolving nanoemulsifying technique

Berberine, an isoquinoline alkaloid, has wide biological and pharmacological actions. Despite the promising pharmacological effects and safety of berberine, poor oral absorption due to its extremely low aqueous solubility results in poor oral systemic bioavailability. This limits its clinical usage. This study describes the development and characterization of self-nanoemulsifying drug delivery system (SNEDDS) of berberine in liquid as well as solid form with improved solubility, dissolution and in vivo therapeutic efficacy. The SNEDDS of berberine were prepared using Acrysol K-150, Capmul MCM and polyethylene glycol 400. The formulations were characterized for various in vitro physicochemical characteristics. In vivo efficacy was evaluated in acetic acid induced inflammatory bowel model in rats. Anti-angiogenic activity of the developed SNEDDS of berberine was studied using chick chorioallantoic membrane assay. SNEDDS of berberine rapidly formed nanoemulsions with globule size of 17-45 nm. The in vitro rate and extent of release of berberine from SNEDDS was significantly higher than berberine alone. Chick chorioallantoic membrane assay revealed potent anti-angiogenic activity of SNEDDS of berberine. These studies demonstrate that the SNEDDS of berberine is a promising strategy for improving its therapeutic efficacy and have potential application in the treatment of chronic inflammatory conditions and cancer.

The lectin-like oxidized low-density lipoprotein receptor-1 as therapeutic target for atherosclerosis, inflammatory conditions and longevity

INTRODUCTION

The lectin-like oxidized LDL receptor-1 (LOX-1) is a scavenger receptor and is regarded as a central element in the initiation of endothelial dysfunction and its further progression to atherosclerosis. Increasing numbers of studies suggest that therapeutic strategies to modulate LOX-1 will have a broad spectrum of applications ranging from cardiovascular diseases to longevity.

AREAS COVERED

The dual role of LOX-1 as a culprit molecule in the process of atherosclerosis and as a danger signal in various tissues is introduced. The structure of the receptor, its ligands and its modulation by known drugs, by natural products (e.g., statins, imipramine, salicylate-based drugs, procyanidins, curcumin) and by new strategies (antisenseRNA, miRNA, pyrrole-imidazol-polyamides, LOX-1 antibodies, lipid apheresis) are described.

EXPERT OPINION

Therapeutic approaches via transcript regulation, allowing a modulation of LOX-1, may be an easier and safer strategy than a blockade of the receptor. Considering the wide distribution of LOX-1 on different tissues, research on the mechanisms of LOX-1 modulation by drugs and natural products applying "omic"-technologies will not only allow a better understanding of the role of LOX-1 in the processes of atherosclerosis, inflammation and longevity but also support the development of specific LOX-1 modulators, avoiding the initiation of molecular mechanisms which lead to adverse events.