Open forum conference on the ICH M13A bioequivalence guideline

The Network on Bioavailability and Biopharmaceutics of EUFEPS (European Federation for Pharmaceutical Sciences) had organised an Open Discussion Forum on the ICH M13A draft "Guideline on bioequivalence for immediate-release solid oral dosage forms". This conference was cosponsored by the Arbeitsgemeinschaft Pharmazeutische Verfahrenstechnik (APV) and the Frankfurt Foundation Quality of Medicines. Scientists from academia and industry attended this workshop on May 15, 2023, in Frankfurt/Germany, to discuss the suggested regulations with the European members of the ICH drafting group. The aim of this report is to summarise and highlight the main discussion points such as choice of study population (females and/or males), request for fasted and/or fed studies, consequences of differences in drug product content, handling of aberrant plasma profiles and additional requirements in case of pH-dependant solubility. During the discussion important arguments were presented for a revision of certain requirements suggested in the draft guideline.

Design and Characterization of Carboplatin and Paclitaxel Loaded PCL Filaments for 3D Printed Controlled Release Intrauterine Implants

Uterine cancer is the fourth most common cancer in women. Despite various chemotherapy approaches, the desired effect has not yet been achieved. The main reason is each patient responds differently to standard treatment protocols. The production of personalized drugs and/or drug-loaded implants is not possible in today’s pharmaceutical industry; 3D printers allow for the rapid and flexible preparation of personalized drug-loaded implants. However, the key point is the preparation of drug-loaded working material such as filament for 3D printers. In this study, two different anticancer (paclitaxel, carboplatin) drug-loaded PCL filaments with a 1.75 mm diameter were prepared with a hot-melt extruder. To optimize the filament for a 3D printer, different PCL Mn, cyclodextrins and different formulation parameters were tried, and a series of characterization studies of filaments were conducted. The encapsulation efficiency, drug release profile and in vitro cell culture studies have shown that 85% of loaded drugs retain their effectiveness, provide a controlled release for 10 days and cause a decrease in cell viability of over 60%. In conclusion, it is possible to prepare optimum dual anticancer drug-loaded filaments for FDM 3D printers. Drug-eluting personalized intra-uterine devices can be designed for the treatment of uterine cancer by using these filaments.

Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors

Colorectal cancer (CRC) is the third most diagnosed cancer type globally and ranks second in cancer-related deaths. With the current treatment possibilities, a definitive, safe, and effective treatment approach for CRC has not been presented yet. However, new drug delivery systems show promise in this field. Amphiphilic cyclodextrin-based nanocarriers are innovative and interesting formulation approaches for targeting the colon through oral administration. In our previous studies, oral chemotherapy for colon tumors was aimed and promising results were obtained with formulation development studies, mucin interaction, mucus penetration, cytotoxicity, and permeability in 2D cell culture, and furthermore in vivo antitumoral and antimetastatic efficacy in early and late-stage colon cancer models and biodistribution after single dose oral administration. This study was carried out to further elucidate oral camptothecin (CPT)-loaded amphiphilic cyclodextrin nanoparticles for the local treatment of colorectal tumors in terms of their drug release behavior and efficacy in 3-dimensional tumor models to predict the in vivo efficacy of different nanocarriers. The main objective was to build a bridge between formulation development and in vitro phase and animal studies. In this context, CPT-loaded polycationic-β-cyclodextrin nanoparticles caused reduced cell viability in CT26 and HT29 colon carcinoma spheroid tumors of mice and human origin, respectively. In addition, the release profile, which is one of the critical quality parameters in new drug delivery systems, was investigated mathematically by release kinetic modeling for the first time. The overall findings indicated that the strategy of orally targeting anticancer drugs such as CPT with positively charged poly-β-CD-C6 nanoparticles to colon tumors for local and/or systemic efficacy is a promising approach.

Synergistic Antitumor Potency of a Self-Assembling Cyclodextrin Nanoplex for the Co-Delivery of 5-Fluorouracil and Interleukin-2 in the Treatment of Colorectal Cancer

Chemotherapy is the most used method after surgery in the treatment of colon cancer. Cancer cells escape the recognition mechanism of immune system cells to survive and develop chemoresistance. Therefore, the use of immunotherapy in combination with chemotherapy can increase the effectiveness of the treatment. Nanoparticles have been used clinically to increase the accumulation of therapeutics in target tissues and reduce toxicity. In this paper, nanoplexes were formed via cationic cyclodextrin polymer, 5-Fluorouracil, and Interleukin-2 based on the opposite charge interaction of macromolecules without undergoing any structural changes or losing the biological activity of Interleukin-2. Anticancer activities of nanoplexes were determined in two-dimensional and three-dimensional cell culture setups. The dual drug-loaded cyclodextrin nanoplexes diffused deeper into the spheroids and accelerated apoptosis when compared with 5-FU solutions. In the colorectal tumor-bearing animal model, survival rate, antitumor activity, metastasis, and immune response parameters were assessed using a cyclodextrin derivative, which was found to be safe based on the ALT/AST levels in healthy mice. Histomorphometric analysis showed that the groups treated with the nanoplex formulation had significantly fewer initial tumors and lung foci when compared with the control. The dual drug-loaded nanoplex could be a promising drug delivery technique in the immunochemotherapy of colorectal cancer.

A different approach to immunochemotherapy for colon Cancer: Development of nanoplexes of cyclodextrins and Interleukin-2 loaded with 5-FU

Immune system deficiencies are crucial in the progression of cancer, predominantly because immune cells are not stimulated by cytokines to eradicate cancer cells. Immunochemotherapy is currently considered an innovative approach that creates pathways in cancer treatment, sometimes also aiding in the efficacy of chemotherapeutics. The aim of this study was to prepare a cyclodextrin (CD) nanoplex based on charge interaction to deliver the anticancer drug 5-fluorouracil (5-FU) and Interleukin-2 (IL-2), thereby forming a nanoscale drug delivery system aimed at chemo-immunotherapy for colorectal cancers. The CD:IL-2 nanoplexes were obtained with a particle size below 100 nm and a cationic surface charge based on the extent of charge interaction of the cationic CD polymer with negatively charged IL-2. The loading capacity of CD nanoplexes was 40% for 5-FU and 99.8% for IL-2. Nanoplexes maintained physical stability in terms of particle size and zeta potential in aqueous solution for 1 week at + 4 °C. Moreover, the structural integrity of IL-2 loaded into CD nanoplexes was confirmed by SDS-PAGE analysis. The cumulative release rates of both 5-FU and IL-2 were found to be more than 80% in simulated biological fluids in 12 h. Cell culture studies demonstrate that CD polymers are safe on healthy L929 mouse fibroblast cells. Drug-loaded CD nanoplexes were determined to have a higher anticancer effect than free drug solution against CT26 mouse colon carcinoma cells. In addition, intestinal permeability studies supported the conclusion that CD nanoplexes could be promising candidates for oral chemotherapy as well. In conclusion, effective cancer therapy utilizing the absorptive/cellular uptake effect of CDs, the synergic effect and co-transport of chemotherapeutic drugs and immunotherapeutic molecules is a promising approach. Furthermore, the transport of IL-2 with this nano-sized system can reduce or avoid its toxicity problem in the clinic.

Nanocarriers targeting the diseases of the pancreas

Diseases of the pancreas include acute and chronic pancreatitis, exocrine pancreatic insufficiency, diabetes and pancreatic cancer. These pathologies can be difficult to treat due to the innate properties of the pancreas, its structure and localization. The need for effective targeting of the pancreatic tissue by means of nanoparticles delivering therapeutics is a major focus area covered and discussed in this review. Most common diseases of the pancreas do not have specific and direct medical treatment option, and existing treatment options are generally aimed at relieving symptoms. Diabetes has different treatment options for different subtypes based on insulin having stability problems and requiring injections reducing patient compliance. Pancreatic cancer progresses silently and can only be diagnosed in advanced stages. Therefore, survival rate of patients is very low. Gemcitabine and FOLFIRINOX treatment regimens, the most commonly used clinical standard treatments, are generally insufficient due to the chemoresistance that develops in cancer cells and also various side effects. Therefore new treatment options for pancreatic cancer are also under focus. Overcoming drug resistance and pancreatic targeting can be achieved with active and passive targeting methods, and a more effective and safer treatment regimen can be provided at lower drug doses. This review covers the current literature and clinical trials concerning pancreatic drug delivery systems in the nanoscale focusing on the challenges and opportunities provided by these smart delivery systems.

Q-TOF LC/MS-based Untargeted Metabolomics Approach to Evaluate the Effect of Folate-Conjugated Cyclodextrins on Triple-Negative Breast Cancer Cells

Background:

Breast cancer is a heterogenic disease that comprises of various morphologies with intrinsic subtypes and is principally responsible for casualties among female cancer patients. Triple-negative breast cancer (TNBC) is the most aggressive subtype with a high probability of relapsing, hence successful treatment can be quite challenging. The pathogenesis of TNBC remains ambiguous and the identification of dependable biomarkers for its early diagnosis is crucial to design a strategy for therapeutic armamentarium.

Objective:

To clarify the folate-dependent mechanism of action causing cell death and to unravel the potential biomarkers of TNBC to defeat this consequential public health burden.

Methods:

The MTT assay and the morphological examination via microscopy were carried out to examine the viability of the cells upon the administration of the blank folate-conjugated cyclodextrin nanoparticles. An untargeted metabolomic approach using Q-TOF LC/MS was performed. Multivariate analysis of the metabolomic profile was applied to the MDA-MB-231 cell line with the aim of comparing the untreated cells with the folate-conjugated cyclodextrin nanoparticles applied cells to detect possible biomarkers.

Results:

The spectrophotometric and microscopic analyses revealed that MDA-MB-231 cells underwent early apoptosis following the incubation with the folate-conjugated nanoparticles for 24 h of administration. Moreover, metabolomics profiling pointed out that hexose metabolism was significantly altered. Data mining procedures showed that glycolysis, mannose, fructose, and galactose were the most affected pathways in TNBC upon blank folate-conjugated cyclodextrin nanoparticle administration and this effect was determined to be cell-specific. A perturbed hexose pathway may be the explanation of selective cell death and decelerated cell growth seen in TNBC cells.

Conclusions:

Our study offers a new understanding of the underlying mechanisms of TNBC since we hereby provide evidence that hexose is one of the main driving forces for the metabolic mechanism over TNBC cells. This alternative mechanistic approach may markedly increase the effect of chemotherapy on TNBC.

Therapeutic efficacy and gastrointestinal biodistribution of polycationic nanoparticles for oral camptothecin delivery in early and late-stage colorectal tumor-bearing animal model

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world and is the second leading cause of cancer related deaths. New cases are increasingly diagnosed every day, but current therapeutic options are still insufficient for an effective treatment. In CRC treatment, there is a significant need for alternative treatment approaches that can both prevent relapse and provide strong antimetastatic effects as the intestines and colon are prone to metastasis to neighboring organs and tissues as well as the liver and the lung. In this study, optimized polycationic cyclodextrin (CD) nanoparticles for oral Camptothecin (CPT) delivery were comprehensively examined for in vivo performance in early and late stage tumor bearing mouse model in terms of antitumoral and antimetastatic efficacy of CPT bound to polycationic CD nanoparticles in comparison to free CPT. In addition, the gastrointestinal localization of a single administration of fluorescent dye loaded polycationic CD nanoparticles in the gastrointestinal tract at the end of 24 hours after oral administration was also imaged and evaluated by in vivo imaging system against fluorescent dye intensity. Results showed that survival percentage was significantly improved in CRC-bearing mice compared to oral CPT solution, with significantly reduced colorectal tumor masses and number of liver metastatic foci (p<0.05). It was also possible to differentiate between the effectiveness of nanoparticles in early or late stages of CRC. In vivo imaging studies have also confirmed that polycationic CD nanoparticles are able to deliver the therapeutic load up to the colon and tend to accumulate especially in tumor foci, indicating an effective local treatment strategy. In addition number of liver metastases were significantly decreased with the CPT-loaded polycationic CD nanoparticle formulation in both early and late stage tumor models. These findings indicated that CPT-loaded polycationic CD nanoparticles could be an efficient oral nanocarrier formulation for anticancer molecules that have limited application because of oral bioavailability and stability problems.

Erlotinib complexation with randomly methylated β-cyclodextrin improves drug solubility, intestinal permeability, and therapeutic efficacy in non-small cell lung cancer

The purpose of this study was to investigate the impact of anticancer drug erlotinib-randomly methylated-β-cyclodextrin complex (ERL-RAMEB CD) on drug solubility and dissolution rate. Phase solubility study showed erlotinib displayed maximum solubility in RAMEB CD solution and the stability constant (K_c) was calculated to be 370 ± 16 M^-1. The optimal formulation was obtained with ERL-RAMEB CD in a 1:1 molar ratio using the co-lyophilization technique. Differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM) verified the inclusion of complex formation. In vitro dissolution study confirmed ERL-RAMEB CD as a favorable approach to increase drug dissolution with a 1.5-fold increase than free ERL at 1 h. An improved dissolution with ∼88.4% drug release at 1 h was observed, in comparison with Erlotinib with ∼58.7% release in 45 min. The in vitro cytotoxicity results indicated that the ERL-RAMEB CD inclusion complex reduced cell viability than free erlotinib. Caco-2 cell uptake that is indicative of drug intestinal permeability resulted in a 5-fold higher uptake of ERL-RAMEB CD inclusion complex than the ERL solution. Hence, ERL-RAMEB CD complexation displays a strong potential to increase dissolution and permeability of erlotinib leading eventually to enhanced oral bioavailability.

A Review on Cancer Immunotherapy and Applications of Nanotechnology to Chemoimmunotherapy of Different Cancers

Clinically, different approaches are adopted worldwide for the treatment of cancer, which still ranks second among all causes of death. Immunotherapy for cancer treatment has been the focus of attention in recent years, aiming for an eventual antitumoral effect through the immune system response to cancer cells both prophylactically and therapeutically. The application of nanoparticulate delivery systems for cancer immunotherapy, which is defined as the use of immune system features in cancer treatment, is currently the focus of research. Nanomedicines and nanoparticulate macromolecule delivery for cancer therapy is believed to facilitate selective cytotoxicity based on passive or active targeting to tumors resulting in improved therapeutic efficacy and reduced side effects. Today, with more than 55 different nanomedicines in the market, it is possible to provide more effective cancer diagnosis and treatment by using nanotechnology. Cancer immunotherapy uses the body's immune system to respond to cancer cells; however, this may lead to increased immune response and immunogenicity. Selectivity and targeting to cancer cells and tumors may lead the way to safer immunotherapy and nanotechnology-based delivery approaches that can help achieve the desired success in cancer treatment.

Polycationic cyclodextrin nanoparticles induce apoptosis and affect antitumoral activity in HepG2 cell line: An evaluation at the molecular level

Hepatocellular carcinoma (HCC) is a highly metastatic primary liver cancer generating molecular alterations that end up escaping the apoptotic machinery and conferring multidrug resistance. Targeted medicines with increased and selective cytotoxicity and minimal drug resistance are essential for the treatment of HCC. In this study, a self-assembled polycationic (PC) amphiphilic β-cyclodextrin (βCDC6) nanoparticle formulation was characterized and its efficacy over HCC cell line HepG2 was evaluated in terms of cytotoxicity, apoptotic potential, chemosensitivity and mitochondrial balance utilizing biochemical, gene expression and proteomic approaches without encapsulating an anti-neoplastic agent. Blank PC βCDC6 exerted an anti-proliferative effect on 3D multicellular HepG2 spheroid tumors. These nanoparticles were able to trigger apoptosis proved by caspase 3/7 activity, gene expression and flow cytometry studies. The subjection of PC restored the chemosensitivity of HepG2 cells by suppressing the function of p-glycoprotein. The proteomic studies with Q-TOF LC/MS revealed 73 proteins that are aberrantly encoded after cells were treated with the blank PC. Metabolomic analysis further confirmed the shift in certain biological pathways. Thus, we confirmed that the hepatocellular carcinoma-targeting βCDC6 PC nanoparticles induce apoptosis, lower the rate of cell proliferation, hinder multidrug resistance and they are convenient carriers for eventual therapeutic administrations in HCC patients.

ACPA decreases non-small cell lung cancer line growth through Akt/PI3K and JNK pathways in vitro

Therapeutic agents used for non-small cell lung cancer (NSCLC) have limited curative efficacy and may trigger serious adverse effects. Cannabinoid ligands exert antiproliferative effect and induce apoptosis on numerous epithelial cancers. We confirmed that CB1 receptor (CB1R) is expressed in NSCLC cells in this study. Arachidonoylcyclopropylamide (ACPA) as a synthetic, CB1R-specific ligand decreased proliferation rate in NSCLC cells by WST-1 analysis and real-time proliferation assay (RTCA). The half-maximal inhibitory concentration (IC50) dose of ACPA was calculated as 1.39 × 10-12 M. CB1 antagonist AM281 inhibited the antiproliferative effect of ACPA. Flow cytometry and ultrastructural analyzes revealed significant early and late apoptosis with diminished cell viability. Nano-immunoassay and metabolomics data on activation status of CB1R-mediated pro-apoptotic pathways found that ACPA inhibited Akt/PI3K pathway, glycolysis, TCA cycle, amino acid biosynthesis, and urea cycle and activated JNK pathway. ACPA lost its chemical stability after 24 hours tested by liquid chromatography-mass spectrometry (LC-MS/MS) assay. A novel ACPA-PCL nanoparticle system was developed by nanoprecipitation method and characterized. Sustained release of ACPA-PCL nanoparticles also reduced proliferation of NSCLC cells. Our results demonstrated that low dose ACPA and ACPA-PCL nanoparticle system harbor opportunities to be developed as a novel therapy in NSCLC patients that require further in vivo studies beforehand to validate its anticancer effect.

Erlotinib entrapped in cholesterol-depleting cyclodextrin nanoparticles shows improved antitumoral efficacy in 3D spheroid tumors of the lung and the liver

Erlotinib (ERL), a tyrosine kinase inhibitor approved for therapeutic use in non-small cell lung cancer is further researched for eventual liver cancer treatment. However, conventional ERL has important bioavailability problems resulting from oral administration, poor solubility and gastrointestinal degradation into inactive metabolites. Alternative administration routes and nanoparticulate drug delivery systems are studied to prevent or reduce these drawbacks. In this study, ERL-loaded CD nanosphere and nanocapsule formulations capable of cholesterol depletion in resistant cancer cells were evaluated for ERL delivery. Drug loading and release profile depended largely on the surface charge of nanoparticles. Antiproliferative activity data obtained from 2D and 3D cell culture models demonstrated that polycationic βCD nanocapsules were the most effective formulation for ERL delivery to lung and liver cancer cells. 3D tumour tumoral penetration studies further revealed that nanocapsule formulations penetrated deeper into the tumour through the multilayered cells. Furthermore, all formulations were able to extract membrane cholesterol from lung and liver cancer cell lines, indicating the induction of apoptosis and overcoming drug resistance. In conclusion, given their tumoral penetration and cell membrane cholesterol depletion abilities, amphiphilic CD nanocapsules emerge as promising alternatives to improve the safety and efficiency of ERL treatment of both liver and lung tumours.

Cyclodextrin nanoparticle bound oral camptothecin for colorectal cancer: Formulation development and optimization

Chemotherapeutic drugs for colorectal cancer(CRC) which is currently the third most lethal cancer globally, are administered intravenously (iv) due to their low oral bioavailability resulting from their physicochemical properties. Non-selective biodistribution and difficulties of parenteral administration reduce treatment efficacy. The aim of this work is to develop cyclodextrin (CD) based cationic nanoparticles (NPs) for CRC treatment with model drug camptothecin (CPT) that can be administered orally, protecting CPT through gastrointestinal tract (GIT), accumulating at mucus layer and providing an effective local treatment for the tumor area. NPs using two different amphiphilic CDs were prepared and coated with polyethylenimine (PEI) or chitosan (CS) to obtain positively charged surface for all formulations. Pre-formulation studies resulted in optimal formulation, CPT loaded Poly-β-CD-C6 NPs, with 135 nm diameter and zeta potential of + 40 mV. In vitro release study was designed to represent gastrointestinal pH and transit time revealing 52% of encapsulated CPT successfully delivered all the way to simulated colon. CPT bound to Poly-β-CD-C6 NPs exhibited higher cytotoxicity on HT-29 cells compared to equivalent CPT in solution. Caco-2 cell permeability studies showed 276% increase in CPT permeability and significantly higher mucosal penetration in cationic CD nanoparticle form.

Nanocapsules for Drug Delivery: An Updated Review of the Last Decade

BACKGROUND

For the past few decades, there has been considerable research interest in drug delivery strategies using nanoparticulate systems as carriers for a wide range of active pharmaceutical ingredients.

OBJECTIVE

It is known that nanoparticulate drug delivery systems comprise a wide variety of dosage forms including nanospheres, micelles, solid lipid nanoparticles, nanoliposomes, dendrimers, magnetic nanoparticles, and nanocapsules.

METHODS

This review describes nanocapsule preparation techniques and their applications for the treatment of several diseases using patents and examples from the literature.

RESULTS

Nanocapsules are vesicular systems consisting of an inner liquid core (aqueous/oily) surrounded by a polymeric wall that has immense potential as drug carriers because of the many advantages like improving poor aqueous solubility, stabilizing drugs by protecting the molecule from the environment, providing the desired pharmacokinetic profile, allowing controlled release, as well as facilitating oral administration.

CONCLUSION

The present study discusses and summarizes patents related to preparation methods of and recent studies from the last 10 years on nanocapsules as drug delivery systems.

Mechanical characterization and ex vivo evaluation of anticancer and antiviral drug printed bioadhesive film for the treatment of cervical cancer

As research progresses on personalized medicines, it is clear that personalized and flexible formulations can provide effective treatment with reduced side effects especially for diseases like cancer, characteristic of high patient variability. 2D and 3D printers are frequently reported in the literature for the preparation of pharmaceutical products with adjusted dose and selected drug combinations. However, in-depth characterization studies of these formulations are rather limited. In this paper, ex vivo and mechanical characterization studies of antiviral and anticancer drug printed film formulations designed for personalized application were performed. Effects of the printing process with pharmaceutical formulations such as paclitaxel (PCX):cyclodextrin (CD) complex or cidofovir (CDV) encapsulated into poly(ethylene glycol)-polycaprolactone (PEG-PCL) nanoparticles on the films were evaluated through a series of mechanical characterization studies. Inkjet printing process was found to cause no significant change in the thicknesses of the film formulations, while mechanical strength and surface free energy increased and nano-sized voids in the film structure decreased. According to the mechanical characterization data, the unprinted film had maximum force (F_max) value of 15.6 MPa whereas F_max increased to 43.8 MPa for PCX:CD complex printed film and to 37.7 MPa for the antiviral CDV-PEG-PCL nanoparticle printed film. In the light of ex vivo findings of sheep cervix-uterine tissue, bioadhesive properties of film formulations significantly improved after inkjet printing with different drug formulations. It has also been shown that the anticancer formulation printed on the film was maintained at the cervix tissue surface for >12 h. This study has shown for the first time that inkjet printing process does not adversely affect the mechanical properties of the bioadhesive film formulations. It has also been shown that durable bioadhesive film formulations for personalized dosing can be prepared by combining nanotechnology and inkjet printing.

Global omics strategies to investigate the effect of cyclodextrin nanoparticles on MCF-7 breast cancer cells

Cyclodextrins (CD) are natural macrocyclic oligosaccharides linked by α(1,4) glycosidic bonds. Hydrophobic cavity of CDs are able to incorporate small molecules, ions, macromolecules which makes them excellent delegates for forming nanoparticulate carriers upon chemical modification to render amphiphilicity to CDs. In this study, blank 6OCaproβCD nanoparticle was prepared and administered to MCF-7 breast cancer cells. The effects of these nanoparticles on the cells were investigated in depth through biochemical and proteomic tests following 48 h of incubation. Proteomics studies revealed that apoptosis-related protein levels of hnRNP and CBX1 were increased while HDGF was not affected supporting the idea that 6OCaproβCD nanoparticles prevent cell proliferation. Gene expression studies were generally in correlation with protein levels since gene expression was significantly stimulated while protein levels were lower compared to the control group suggesting that a post-transcriptional modification must have occurred. Furthermore, 6OCaproβCD was observed to not trigger multidrug resistance as proved with RT-PCR that effectuates another exquisite characteristic of 6OCaproβCD nanoparticle as carrier of chemotherapeutic drugs. Metabolomic pathways of CD effect on MCF7 cells were elucidated with HMDB as serine biosynthesis, transmembrane transport of small molecules, metabolism of steroid hormones, estrogen biosynthesis and phospholipid biosynthesis. In conclusion, 6OCaproβCD is a promising nanoparticulate carrier for chemotherapeutic drugs with intrinsic apoptotic effect to be employed in treatment of breast cancer and further studies should be conducted in order to comprehend the exact mechanism of action.

Cellular Interaction and Tumoral Penetration Properties of Cyclodextrin Nanoparticles on 3D Breast Tumor Model

Amphiphilic cyclodextrins are biocompatible oligosaccharides that can be used for drug delivery especially for the delivery of drugs with solubility problems thanks to their unique molecular structures. In this paper, Paclitaxel was used as a model anticancer drug to determine the inclusion complex properties of amphiphilic cyclodextrins with different surface charge. Paclitaxel-loaded cyclodextrin nanoparticles were characterized in terms of mean particle diameter, zeta potential, encapsulation efficacy, drug release profile and cell culture studies. It was determined that the nanoparticles prepared from the inclusion complex according to characterization studies have a longer release profile than the conventionally prepared nanoparticles. In order to mimic the tumor microenvironment, breast cancer cells and healthy fibroblast cells were used in 3-dimensional (3D) cell culture studies. It was determined that the activities of nanoparticles prepared by conventional methods behave differently in 2-dimensional (2D) and 3D cell cultures. In addition, it was observed that the nanoparticles prepared from the inclusion complex have a stronger anti-tumoral activity in the 3D multicellular tumor model than the drug solution. Furthermore, polycationic amphiphilic cyclodextrin nanoparticles can diffuse and penetrate through multilayer cells in a 3D tumor model, which is crucial for an eventual antitumor effect.

Development of polycationic amphiphilic cyclodextrin nanoparticles for anticancer drug delivery

Background: Paclitaxel is a potent anticancer drug that is effective against a wide spectrum of cancers. To overcome its bioavailability problems arising from very poor aqueous solubility and tendency to recrystallize upon dilution, paclitaxel is commercially formulated with co-solvents such as Cremophor EL® that are known to cause serious side effects during chemotherapy. Amphiphilic cyclodextrins are favored oligosaccharides as drug delivery systems for anticancer drugs, having the ability to spontaneously form nanoparticles without surfactant or co-solvents. In the past few years, polycationic, amphiphilic cyclodextrins were introduced as effective agents for gene delivery in the form of nanoplexes. In this study, the potential of polycationic, amphiphilic cyclodextrin nanoparticles were evaluated in comparison to non-ionic amphiphilic cyclodextrins and core-shell type cyclodextrin nanoparticles for paclitaxel delivery to breast tumors. Pre-formulation studies were used as a basis for selecting the suitable organic solvent and surfactant concentration for the novel polycationic cyclodextrin nanoparticles. The nanoparticles were then extensively characterized with particle size distribution, polydispersity index, zeta potential, drug loading capacity, in vitro release profiles and cytotoxicity studies. Results: Paclitaxel-loaded cyclodextrin nanoparticles were obtained in the diameter range of 80-125 nm (depending on the nature of the cyclodextrin derivative) where the smallest diameter nanoparticles were obtained with polycationic (PC) βCDC6. A strong positive charge also helped to increase the loading capacity of the nanoparticles with paclitaxel up to 60%. Interestingly, cyclodextrin nanoparticles were able to stabilize paclitaxel in aqueous solution for 30 days. All blank cyclodextrin nanoparticles were demonstrated to be non-cytotoxic against L929 mouse fibroblast cell line. In addition, paclitaxel-loaded nanoparticles have a significant anticancer effect against MCF-7 human breast cancer cell line as compared with a paclitaxel solution in DMSO. Conclusion: According to the results of this study, both amphiphilic cyclodextrin derivatives provide suitable nanometer-sized drug delivery systems for safe and efficient intravenous paclitaxel delivery for chemotherapy. In the light of these studies, it can be said that amphiphilic cyclodextrin nanoparticles of different surface charge can be considered as a promising alternative for self-assembled nanometer-sized drug carrier systems for safe and efficient chemotherapy.

Therapeutic efficacy of folate receptor-targeted amphiphilic cyclodextrin nanoparticles as a novel vehicle for paclitaxel delivery in breast cancer

PURPOSE

The aim of this study is to test folate-conjugated cyclodextrin nanoparticles (FCD-1 and FCD-2) as a vehicle for reducing toxicity and increasing the antitumor efficacy of paclitaxel especially for metastatic breast cancer.

METHODS

For the evaluation of PCX-loaded FCD nanoparticles, animal studies were realised in terms of survival rate, tumour size, weight change, metastazis and histopathological examination.

RESULTS

FCD-1 displayed significant advantages such as efficient targeting of folate receptor positive breast cancer cells and having considerably lower toxicity compared to that of Cremophor^®. When loaded with paclitaxel, FCD-1 nanoparticles, which have smaller particle size, neutral zeta potential, high encapsulation efficiency and better loading capacity for controlled release, emerged as an effective formulation in terms of cytotoxicity and high cellular uptake. In an experimental breast cancer model, anticancer activity of these nanoparticles were compatible with that of paclitaxel in Cremophor^® however repeated administrations of FCD-1 nanoparticles were better tolerated by the animals. These nanoparticles were able to localise in tumour site. Both paclitaxel-loaded FCD-1 and FCD-2 significantly reduced tumour burden while FCD-1 significantly improved the survival.

CONCLUSIONS

Folate-conjugated amphiphilic cyclodextrin nanoparticles can be considered as promising Cremophor^®-free, low-toxicity and efficient active drug delivery systems for paclitaxel.

Amphiphilic cyclodextrin nanoparticles

Cyclodextrins are cyclic oligosaccharides obtained by enzymatic digestion of starch. The α-, β- and γ- cyclodextrins contain respectively 6, 7 and 8 glucopyranose units, with primary and secondary hydroxyl groups located on the narrow and wider rims of a truncated cone shape structure. Such structure is that of a hydrophobic inner cavity with a hydrophilic outer surface allowing to interact with a wide range of molecules like ions, protein and oligonucleotides to form inclusion complexes. Many cyclodextrin applications in the pharmaceutical area have been widely described in the literature due to their low toxicity and low immunogenicity. The most important is to increase the solubility of hydrophobic drugs in water. Chemically modified cyclodextrin derivatives have been synthesized to enhance their properties and more specifically their pharmacological activity. Among these, amphiphilic derivatives were designed to build organized molecular structures, through selfassembling systems or by incorporation in lipid membranes, expected to improve the vectorization in the organism of the drug-containing cyclodextrin cavities. These derivatives can form a variety of supramolecular structures such as micelles, vesicles and nanoparticles. The purpose of this review is to summarize applications of amphiphilic cyclodextrins in different areas of drug delivery, particularly in protein and peptide drug delivery and gene delivery. The article highlights important amphiphilic cyclodextrin applications in the design of novel delivery systems like nanoparticles.

Inkjet printing of antiviral PCL nanoparticles and anticancer cyclodextrin inclusion complexes on bioadhesive film for cervical administration

Personalized medicine is an important treatment approach for diseases like cancer with high intrasubject variability. In this framework, printing is one of the most promising methods since it permits dose and geometry adjustment of the final product. With this study, a combination product consisting of anticancer (paclitaxel) and antiviral (cidofovir) drugs was manufactured by inkjet printing onto adhesive film for local treatment of cervical cancers as a result of HPV infection. Furthermore, solubility problem of paclitaxel was overcome by maintaining this poorly soluble drug in a cyclodextrin inclusion complex and release of cidofovir was controlled by encapsulation in polycaprolactone nanoparticles. In vitro characterization studies of printed film formulations were performed and cell culture studies showed that drug loaded film formulation was effective on human cervical adenocarcinoma cells. Our study suggests that inkjet printing technology can be utilized in the development of antiviral/anticancer combination dosage forms for mucosal application. The drug amount in the delivery system can be accurately controlled and modified. Moreover, prolonged drug release time can be obtained. Printing of anticancer and antiviral drugs on film seem to be a potential approach for HPV-related cervical cancer treatment and a good candidate for further studies.

Cationic PEGylated polycaprolactone nanoparticles carrying post-operation docetaxel for glioma treatment

Background: Brain tumors are the most common tumors among adolescents. Although some chemotherapeutics are known to be effective against brain tumors based on cell culture studies, the same effect is not observed in clinical trials. For this reason, the development of drug delivery systems is important to treat brain tumors and prevent tumor recurrence. The aim of this study was to develop core-shell polymeric nanoparticles with positive charge by employing a chitosan coating. Additionally, an implantable formulation for the chemotherapeutic nanoparticles was developed as a bioadhesive film to be applied at the tumor site following surgical operation for brain glioma treatment. To obtain positively charged, implantable nanoparticles, the effects of preparation technique, chitosan coating concentration and presence of surfactants were evaluated to obtain optimal nanoparticles with a diameter of less than 100 nm and a net positive surface charge to facilitate cellular internalization of drug-loaded nanoparticles. Hydroxypropyl cellulose films were prepared to incorporate these nanoparticle dispersions to complete the implantable drug delivery system. Results: The diameter of core-shell nanoparticles were in the range of 70-270 nm, depending on the preparation technique, polymer type and coating. Moreover, the chitosan coating significantly altered the surface charge of the nanoparticles to net positive values of +30 to +50 mV. The model drug docetaxel was successfully loaded into all particles, and the drug release rate from the nanoparticles was slowed down to 48 h by dispersing the nanoparticles in a hydroxypropyl cellulose film. Cell culture studies revealed that docetaxel-loaded nanoparticles cause higher cytotoxicity compared to the free docetaxel solution in DMSO. Conclusion: Docetaxel-loaded nanoparticles dispersed in a bioadhesive film were shown to be suitable for application of chemotherapeutics directly to the action site during surgical operation. The system was found to release chemotherapeutics for several days at the tumor site and neighboring tissue. This can be suggested to result in a more effective brain tumor treatment when compared to chemotherapeutics administered as an intravenous bolus infusion.

Design and optimization of novel paclitaxel-loaded folate-conjugated amphiphilic cyclodextrin nanoparticles

As nanomedicines are gaining momentum in the therapy of cancer, new biomaterials emerge as alternative platforms for the delivery of anticancer drugs with bioavailability problems. In this study, two novel amphiphilic cyclodextrins (FCD-1 and FCD-2) conjugated with folate group to enable active targeting to folate positive breast tumors were introduced. The objective of this study was to develop and characterize new folated-CD nanoparticles via 3(2) factorial design for optimal final parameters. Full physicochemical characterization studies were performed. Blank and paclitaxel loaded FCD-1 and FCD-2 nanoparticles remained within the range of 70-275nm and 125-185nm, respectively. Zeta potential values were neutral and -20mV for FCD-1 and FCD-2 nanoparticles, respectively. Drug release studies showed initial burst release followed by a longer sustained release. Blank nanoparticles had no cytotoxicity against L929 cells. T-47D and ZR-75-1 human breast cancer cells with different levels of folate receptor expression were used to assess anti-cancer efficacy. Through targeting the folate receptor, these nanoparticles were efficiently engulfed by the breast cancer cells. Additionally, breast cancer cells became more sensitive to cytotoxic and/or cytostatic effects of PCX delivered by FCD-1 and FCD-2. In conclusion, these novel folate-conjugated cyclodextrin nanoparticles can therefore be considered as promising alternative systems for safe and effective delivery of paclitaxel with a folate-dependent mechanism.

Localized delivery of methylprednisolone sodium succinate with polymeric nanoparticles in experimental injured spinal cord model

With important social and economic consequences, spinal cord injuries (SCIs) still exist among major health problems. Although many therapeutic agents and methods investigated for the treatment of acute SCI, only high dose methylprednisolone (MP) is being used currently in practice. Due to the serious side effects, high dose systemic MP administration after SCI is a critical issue that is mostly considered controversial. In our study, it is aimed to develop a nanoparticle-gel combined drug delivery system for localization of MP on trauma site and eliminating dose-dependent side effects by lowering the administered dose. For this purpose, methyl prednisolone sodium succinate (MPSS) loaded polycaprolactone based nanoparticles were developed and embedded in an implantable fibrin gel. The effects of MPSS delivery system are evaluated on an acute SCI rat model, by quantification the levels of three inflammatory cytokines (interleukin-1β, interleukin-6 and caspase-3) and assessment of the damage on ultrastructural level by transmission electron microscopy. Developed NP-gel system showed very similar results with systemic high dose of MPSS. It is believed that developed system may be used as a tool for the safe and effective localized delivery of several other therapeutic molecules on injured spinal cord cases.

Antitumor Efficacy of Bacillus Calmette-Guerin Loaded Cationic Nanoparticles for Intravesical Immunotherapy of Bladder Tumor Induced Rat Model

For bladder cancer, intravesical chemo/immunotherapy is widely used as adjuvant therapy after surgical transurethral resection. Bacillus Calmette-Guerin (BCG) is a live attenuated Mycobacterium of the same family as tuberculosis, that is capable of inducing a local inflammatory response upon instillation into the bladder. Intravesical therapy with BCG has proved to be more effective in the prophylaxis and treatment of superficial bladder tumors than most chemotherapeutic agents used for the same indication. However, compared to intravesical chemotherapy, BCG immunotherapy provokes more pronounced local and systemic reactions. In addition to the commonly induced granulomatous inflammatory changes in the bladder, which produce irritative symptoms, this therapy may cause systemic side effects varying from mild malaise and fever to, in rare instances, life-threatening or fatal sepsis. Nanoparticles with positive surface charge and mucoadhesive properties were developed to overcome these side effects. Hence, the aim of this study was to optimize and evaluate cationic chitosan (CS) nanoparticles encapsulating BCG in terms of antitumor efficacy after intravesical administration in bladder tumor, induced in rat model. It was found that nanoparticle formulations of 269-375 nm in size can be produced with 42% encapsulation efficiency. The zeta potential was positive and was suitable for intravesical administration. Antitumor efficacy was determined over the parameters of histopathological evaluation, survival rate and mean bladder weight in comparison to treatment with commercial BCG solution. Concerning survival rates, BCG-loaded chitosan nanoparticles resulted in significantly longer survival than BCG commercial product (up to 86 days of survival with no systemic side effects). When compared to healthy bladder weight averages, all groups (especially BCG commercial solution) showed higher bladder weights confirming tumor formation. Histopathological findings confirmed antitumor activity in all treatment groups and optimum findings were observed in groups treated with CS nanoparticles encapsulating BCG. At the same time, significant nanoparticle accumulation in bladder tissues was observed especially for BCG-loaded CS group. In this study, it was clearly observed that cationic CS nanoparticles provide a significantly improved perspective in intravesical immunotherapy of bladder tumors.

Formulation development, stability and anticancer efficacy of core-shell cyclodextrin nanocapsules for oral chemotherapy with camptothecin

BACKGROUND

The aim of this study was to design and evaluate hybrid cyclodextrin (CD) nanocapsules intended for the oral delivery of the anticancer agent camptothecin (CPT) in order to maintain drug stability in the body and to improve its eventual bioavailability. For this reason, an amphiphilic cyclodextrin (CD) derivative per-modified on the primary face 6OCAPRO was used as core molecule to form nanocapsules with the nanoprecipitation technique. Nanocapsules were further coated with the cationic polymer chitosan to improve the cellular uptake and interaction with biological membranes through positive surface charge. Nanocapsules were evaluated for their in vitro characteristics such as particle size, zeta potential, drug loading and release profiles followed by cell culture studies with the MCF-7 and Caco-2 cell line evaluating their anticancer efficacy and permeability. The CD nanocapsules were imaged by scanning electron microscopy (SEM). The concentration of CPT entrapped in nanocapsules was determined by reversed phase HPLC. The in vitro release study of CPT was performed with a dialysis bag method under sink conditions mimicking the gastric and intestinal pH. The hydrolytic stability of CPT in nanocapsules was investigated in simulated gastric and intestinal fluids (SGF, SIF).

RESULTS

The mean particle sizes of both anionic and cationic CPT-loaded nanocapsules were in the range of 180-200 nm with polydispersity indices lower than 0.400 indicating monodisperse size distribution of nanocapsules with favourable potential for intracellular drug delivery to tumour cells. Surface charges of anionic and cationic nanocapsules were demonstrated as -21 mV and +18 mV, respectively. The stability of CPT in simulated release media, SGF and SIF were maintained suggesting the improved protection of the drug molecule from rapid hydrolysis degradation or gastrointestinal pH in nanocapsule oily core. Furthermore CD nanocapsules showed higher anticancer efficacy than CPT solution against the MCF-7 cell line. Permeation of CPT across Caco-2 cells was found to be 3 fold higher when incorporated in hybrid CD nanocapsules compared with a DMSO solution.

CONCLUSION

Oral CD nanocapsules indicating increased oral bioavailability might be a promising strategy to maintain the physiological stability and to improve the oral bioavailability of problematic anticancer drugs such as CPT which may contribute to patient quality of life and drug efficacy in cancer therapy.

Cationic core-shell nanoparticles for intravesical chemotherapy in tumor-induced rat model: safety and efficacy

Mitomycin C (MMC) has shown potent efficacy against a wide spectrum of cancers and is clinical first choice in superficial bladder tumors. However, intravesical chemotherapy with MMC has been ineffective due to periodical discharge of the bladder and instability of this drug in acidic pH, both resulting in high rate of tumor recurrence and insufficiency to prevent progression. Nanocarriers may be a promising alternative for prolonged, effective and safe intravesical drug delivery due to their favorable size, surface properties and optimum interaction with mucosal layer of the bladder wall. Hence, the aim of this study was to evaluate and optimize cationic core-shell nanoparticles formulations (based on chitosan (CS) and poly-ϵ-caprolactone (PCL)) in terms of antitumor efficacy after intravesical administration in bladder tumor induced rat model. Antitumor efficacy was determined through the parameters of survival rate and nanoparticle penetration into the bladder tissue. Safety of the formulations were evaluated by histopathological evaluation of bladder tissue as well as observation of animals treated with MMC bound to nanoparticles. Results indicated that chitosan coated poly-ϵ-caprolactone (CS-PCL) nanoparticles presented the longest survival rate among all treatment groups as evaluated by Kaplan-Meier plotting. Histopathological evaluation revealed that cationic nanoparticles were localized and accumulated in the bladder tissue. As intravesical chemotherapy is a local therapy, no MMC was quantified in blood after intravesical instillation indicating no systemic uptake for the drug which could have subsequently led to side effects. In conclusion, core-shell type cationic nanoparticles may be effective tools for the intravesical chemotherapy of recurrent bladder tumors.

The evaluation of topical administration of Bellis perennis fraction on circular excision wound healing in Wistar albino rats

CONTEXT

Bellis perennis L. (Asteraceae) has been used traditionally in the treatment of bruises, broken bones, and wounds by European people.

OBJECTIVE

To investigate the wound healing activity of B. perennis flowers in Wistar albino rats.

MATERIALS AND METHODS

Dried B. perennis flowers were extracted with ethanol, then fractioned with n-butanol and an oinment was prepared. Twelve male adult Wistar rats were used. Six wounds were created for each animal by using circular excision wound model. The first two wounds were treated topically with HOTBp (hydrophilic ointment treatment containing n-butanol fraction). The second two wounds were control group and not treated with anything. The third two wounds were treated only with HOT (hydrophilic ointment treatment without n-butanol fraction). Treatments were applied once a day and lasted for 30 days. Wound samples were excised on days 5(th), 10(th) and 30(th). The percentage of wound healing was calculated by Walker's formula after measurement of the wound area and the tissue samples were examined histopathologically.

RESULTS

The percentages of wound closure (HOTBp: 100%; HOT: 85% and control: 87%) and histopathological observations showed that there were statistically significant differences between HOTBp, HOT and control groups (p < 0.05) at 30(th) day.

DISCUSSION AND CONCLUSION

Topically administered ointment prepared from the n-butanol fraction of B. perennis flowers has a wound healing potential without scar formation in circular excision wound model in rats. Thus, traditional usage of wound healing activity of B. perennis was scientifically verified for the first time.

Prolonged retention and in vivo evaluation of cationic nanoparticles loaded with Mitomycin C designed for intravesical chemotherapy of bladder tumours

To overcome the recurrence problem in bladder tumours; nanoparticles with positive surface charge may improve interaction with biological membranes for intravesical administration. The aim of this study was to design, develop and evaluate (in vitro-in vivo) cationic nanoparticles based on chitosan, poly-L-lysine or polycaprolactone for the effective intravesical delivery of chemotherapeutic agent MMC in a rat model. Poly-L-lysine-coated polycaprolactone nanoparticles and chitosan-coated polycaprolactone nanoparticles were prepared by the double emulsion technique. Chitosan nanoparticles were prepared by ionic gelation. It was found that nanoparticle formulations of 160-320 nm in size can be produced in 14-35% encapsulation efficiency. Variability in the particle size of nanoparticles depended on the preparation method. Encapsulation was increased by two-fold for CS-PCL as a result of the double emulsion technique. Commercial MMC product in solution form and cationic nanoparticle formulations were compared for in vivo bladder retention properties and effect of formulations on urine volume.

Comparative evaluation of in vitro parameters of tamoxifen citrate loaded poly(lactide-co-glycolide), poly(epsilon-caprolactone) and chitosan nanoparticles

Tamoxifen (TAM), the clinical choice for the antiestrogen treatment of advanced or metastatic breast cancer, was formulated in nanoparticulate carrier systems in the form of poly(lactide-co-glycolide) (PLGA), poly-epsilon-caprolactone (PCL) and chitosan (CS) nanoparticles. The PLGA and PCL nanoparticles were prepared by a nanoprecipitation technique whereas the CS nanoparticles were prepared by the ionic gelation method. Mean particle sizes were under 260 nm for PLGA and PCL nanoparticles and around 400 nm for CS nanoparticles. Polydispersity indices were less than 0.4 for all formulations. Zeta potential values were positive for TAM loaded nanoparticles because of the positive charge of the drug. Drug loading values were significantly higher for PCL nanoparticles when compared to PLGA and CS nanoparticles. All nanoparticle formulations exhibited controlled release properties. These results indicate that TAM loaded PLGA, PCL and CS nanoparticles may provide promising carrier systems for tumor targeting.

Alternative oral exemestane formulation: improved dissolution and permeation

Exemestane (EXE) is an irreversible aromatase inactivator used for the treatment of advanced postmenopausal breast cancer. EXE is orally active but its bioavailability is about 5% due to its low solubility in water and the extensive first pass effect. It is known that cyclodextrin (CD) complexation enhances solubility and oral bioavailability of poorly soluble drugs. Thus, it was aimed to design and develop cyclodextrin complexes in powder and tablet forms containing EXE to improve aqueous solubility and in vitro permeability. In this study, inclusion complexes of EXE were prepared with three different CD derivatives (methyl-beta-cyclodextrin, hydroxypropyl-beta-cyclodextrin and hydroxypropyl-gamma-cyclodextrin) and by two different preparation methods (kneading and colyophilization) and the complexes were characterized with (1)H NMR, FT-IR, SEM, X-ray and DSC analyses. Both inclusion complexes and tablet formulations prepared using EXE:CD inclusion complexes showed significant improvement in the dissolution profile of this oral antiestrogen drug. Furthermore, Caco-2 cell permeation studies revealed that apparent permeability constant for EXE was increased by 3-fold via cyclodextrin complexation. In conclusion, complexation of EXE with cyclodextrin derivatives, randomly methylated-beta-cyclodextrin in particular, results in a more efficient tablet formulation with improved dissolution and better permeation suggesting an enhancement in oral bioavailability of the drug.