Current Drug Delivery - Volume 14, Issue 8, 2017

Background: Curcumin is a yellow polyphenolic chemopreventive agent isolated from the rhizomes of Curcuma longa. It is approved as Generally Regarded as Safe by US FDA. Nonetheless, its clinical success is limited due to its poor aqueous solubility, fast metabolism and short biological half-life attributes. Objective: Quercetin-decorated liposomes of curcumin (QCunp) are perceived to be able to overcome these biopharmaceutical drawbacks. Methods: Curcumin liposomes with/without quercetin were prepared by lipid hydration technique. The liposomes were characterized for their particle size, zeta potential, surface morphology, drug loading and release characteristics. The toxicity of the liposomes were evaluated in-vitro and their invivo efficacy were tested against Dalton's ascites lymphoma in mice. Results: Liposomes designed showed particle size of 261.8 ± 2.1 nm with a negative zeta potential of -22.6±1.6 mV. Quercetin decorated liposomes were more effective in increasing the life span and body weight of lymphoma inflicted mice compared to those without quercetin. Similarly, the presence of quercetin also contributed to enhanced cytotoxicity of the liposomal formulation towards HT-29 cells and HCT-15 cells. Conclusion: Newer liposomal design exhibited promising potential to emerge as alternative anticancer therapeutics.

Background: CXCR4 possesses a critical role in several intracellular events such as chemotaxis, invasion and adhesion, which are associated with metastasis of cancer cell. Objective: In this study, CXCR4 targeted polymeric nanoparticle was developed for delivering cytotoxic drug and blocking the chemokine induced migration of cells expressing CXCR4. Method: A peptide which was a linear form of CXCR4 antagonist (LFC131) was attached to PLGA nanoparticles (LFC131-NPs) and PLGA nanoparticles encapsulating DOX (LFC131-DOX-NPs). The cellular binding and internalization of LFC131-DOX-NPs were investigated. Results: The binding and internalization of LFC131-DOX-NPs were higher and more rapidly compared to unconjugated NPs. LFC131-NPs blocked SDF-1α induced migration of BT-549-Luc cells. MTT assays demonstrated that LFC131-NPs and LFC131-DOX-NPs decreased cell viability in a dose dependent manner in 24, 72 and 120 h incubation. Conclusion: A treatment concept of blocking breast cancer cell migration from interaction with SDF- 1α by using LFC131-NPs and then attacking breast cancer cells with doxorubicin might increase the efficacy of current breast cancer treatment.

Background: Nano-scale carbon systems are emerging alternatives in drug delivery and bioimaging applications of which they gradually replace the quantum dots characterized by toxic heavy metal content in the latter application. Objective: The work intended to use carbon nanospheres synthesized from biowaste Sago bark for cancer cell imaging applications. Methods: This study synthesised carbon nanospheres from biowaste Sago bark using a catalyst-free pyrolysis technique. The nanospheres were functionalized with fluorescent dye coumarin-6 for cell imaging. Fluorescent nanosytems were characterized by field emission scanning electron microscopy-energy dispersive X ray, photon correlation spectroscopy and fourier transform infrared spectroscopy techniques. Results: The average size of carbon nanospheres ranged between 30 and 40 nm with zeta potential of -26.8 ± 1.87 mV. The percentage viability of cancer cells on exposure to nanospheres varied from 91- 89 % for N2a cells and 90-85 % for A-375 cells respectively. Speedy uptake of the fluorescent nanospheres in both N2a and A-375 cells was observed within two hours of exposure. Conclusion: Novel fluorescent carbon nanosystem design following waste-to-wealth approach exhibited promising potential in cancer cell imaging applications.

Background: More than 60% of the new drug molecules are lipophilic in nature. Low aqueous solubility and thus poor bioavailability is the main issue for these drugs for successful formulations into oral dosage form. Self-microemulsifying drug delivery systems (SMEDDS) have gained much attention. These are isotropic mixtures of different components (oil, surfactant and cosurfactant) that quickly disperse in gastrointestinal fluid yielding micro/nano-emulsions. These systems contain solubilized drug that is absorbed by lymphatic pathway along with other pathways like diffusion, collisional transfer, intracellular junctions, biliary acid pathway (BA), biliary acid mixed micelles pathway (BAMM) etc. and thus hepatic first pass metabolism is reduced. Stability of conventional SEDDS is considered very high with reference to other drug delivery systems as liposome, nanoparticles, nanoemulsion and micro emulsion. In fact SEDDS does not contain water in their composition which enhances their chemical and physical stability. Very few works have studied the stability of conventional SEDDS as it was confirmed. The major drawback for conventional SEDDS could be- i) high manufacturing cost (as they have to be filled in soft gelatin capsules); ii) interaction of capsule shell components with SEDDS. Therefore, attention has been given to transform liquid into solid SMEDDS by several techniques such as spray drying, spray cooling, super critical fluid technology and using adsorption carriers. Adsorption using solid carriers (Neusilin, Fujicalin, and dextran) is the successful inexpensive technique at initial research level whereas other requires expensive instrumentation. Conclusion: Current review focuses on biopharmaceutical aspects, characterization of SMEDDS and excipients used in the formulation, techniques used for conversion of liquid SMEDDS to solid SMEDDS (including examples of various research reports where these techniques are used). Various adsorbent carriers (alongwith their different features) which have been reported in research papers have been detailed. It thoroughly covers patent literature on SMEDDS and research carried on solid SMEDDS as well which is the most imperative part of the review.

Background: Pharmaceutical cocrystal is an emerging approach to tailor physicochemical and mechanical properties of drug substances. Cocrystals are composed of API and pharmaceutically acceptable coformer. It is used to address the solubility, dissolution, mechanical properties and stability of drugs. Methods: This review discusses introduction to cocrystal, preparation, and characterization, what USFDA says on cocrystal and role of Hansen solubility parameter to predict cocrystal. The effect of cocrystal on drug properties, dependence of cocrystal solubility on pH, concept of drug-drug cocrystal, and aerosil 200 as novel cocrystal former and impact of cocrystal on drug pharmacokinetic has also been presented in this review along with highly selected examples of cocrystals. Finally, how cocrystal offers an opportunity for patents is also delineated. Results: Pharmaceutical cocrystals have ability to tailor physichochemical and mechanical properties of drug substances. It also provides opportunity for patentable invention. Therapeutic efficacy of drugs may be improved via drug-drug cocrystal. Conclusion: The pharmaceutical cocrystals are not fully explored and have potential for future development. Successful drug delivery can be achieved through cocrystallization. Pharmaceutical industry will be beneficial through successful cocrystallization of drug substances.

Skin is the most suitable and recommendable organ of the human body for topical administration and the main route for topical drug delivery system. Drug delivery system is the methodology used to ensure the entry of drugs into the body, reaching their target for pharmacological action. Patients tend to prefer the painless route for drug administration. So, pharmaceutical aerosols came to existence to meet patient compliance. Many variations in excipients with respect to compatibility to drugs, stability and economy are being used to improve the aerosol system of drug delivery. The present review deals with the excipients and constituents used in a pharmaceutical aerosol system as per target delivery. Summary: The review deals with the excipients and constituents used in a pharmaceutical aerosol system as per target delivery. Conclusion: Presently, aerosol drug delivery system has become beneficial as far as faster pharmacological action and economy are concerned. Other than the active pharmaceutical ingredient (API), the pharmacological action of the aerosol system is also dependent on the excipients used as they help the API to penetrate through the skin as fast as possible.

Background: Levofloxacin is a potent antibiotic with severe side effects due to its high doses. Bacterial resistance may be due to frequent use of antibiotics. Biogenic gold nanoparticles conjugated levofloxacin (Au-HSA-LvN-NPs) were developed by Human Serum Albumin (HSA) and nitrate reductasemediated pathways. Methods: Au-HSA-LvN-NPs (size = 27.2 ± 1 nm) were readily generated with high emulsion stability zeta potential (-13.3 mV). The developed nanoparticles were also characterized by UVvisible spectroscopy, Transmission Electron Microscopy and Dynamic Light Scattering techniques. Results: The optimized nanoparticles were found efficient against both Gram-positive bacteria and Gramnegative bacteria specifically S. aureus (MIC-0.373 μg/ml), E. coli (MIC-0.149 μg/ml) and P. aeruginosa (MIC-0.346 μg/ml) respectively. Conclusion: The efficiency of bioconjugated levofloxacin got improved by 1.94 times, 2.89 times and 1.46 times against S. aureus, E. coli and P. aeruginosa respectively, in comparison to pure levofloxacin.

Background: Cabazitaxel (CBZ) is a new taxane approved by FDA for treatment of castration- resistant prostate cancer not responding to docetaxel. However, CBZ is not a suitable substrate for p-glycoprotein 60, an efflux pump which transports anticancer drugs out of malignant cells and is therefore a promising drug for treatment of multidrug resistant tumors. Similar to other taxanes, the presence of Tween 80 in the CBZ formulation shows that it is insoluble in water. Methods: In order to increase the solubility and circulation time of this drug, CBZ-human serum albumin (HSA) conjugate was synthesized. The designed linker was composed of methacrylic acid and N-acetyl cysteine to increase the solubility of CBZ and to increase the efficiency of conjugation. Targeting was performed by poly(ethylene glycol)-folic acid amide bound formation with carboxyl groups of HSA during in the step of nanoparticle formation. Cytotoxicity of nanoparticles was evaluated in vitro on HT-29, as a folate negative cell line, and MDA-MB-231, as a folate positive cell line. Results: H-NMR, Gel Permeation Chromatography, High Pressure Liquid Chromatography and UV spectrophotometry analysis confirmed the composition of conjugates. The resulting nanoparticles had a spherical shape, narrow size distribution and mean diameter of 138 nm. The efficiency of conjugation was 41.6 %. The IC50 of CBZ in targeted nanoparticles was 10.1 and 17.4% lower than that of the free CBZ for HT-29 and MDA-MB-231 cells, respectively. Conclusion: This designed drug delivery system was more water-soluble and had enhanced in vitro characteristics and higher cytotoxic activity on cancer cells.

Background: The solubilization of poorly water-soluble drugs remains challenging. The purpose of this study was to design a liquid formulation that can improve the solubility of poorly water-soluble and weakly acidic ST-246, an anti-smallpox drug. Methods: Soluble ternary cyclodextrin complexations (t-CDs) containing ST-246, 2-hydroxypropyl-β- cyclodextrin (HP-β-CD) and meglumine (MEG) were prepared and optimized. The optimized t-CDs were further characterized using a scanning electron microscope (SEM), Powder X-ray Diffractometry (PXRD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance Spectroscopy (NMR). Results: The solubility of ST-246 improved dramatically from 3 μg/ml (in water, 37°C) to 50 mg/ml in the optimized t-CDs (ST-246/MEG/HP-β-CD, 1:2:6 weight ratio). The results suggested that the drug was associated with MEG through hydrogen bonds and then included into the hydrophobic cavity of HP-β-CD, which might be a major factor for solubility improvement. To determine the exact inclusion mechanism, a Phase Soluble Study (PSS) was also conducted, and it indicated that a 1:1 soluble complex was formed between ST-246 and HP-β-CD and that the action mechanism of MEG was complicated and relied on more than pH modulation. Conclusion: Generally, the optimized ternary cyclodextrin complexation might be a potential formulation strategy for enhancing the solubility and bioavailability of poorly water-soluble ST-246.

Background: Miconazole nitrate has been widely employed in treatment of oral mycoses, however your immediate bio-availability and location in the affected area is critical. Objective: The aim of this study was to prepare and evaluate Eudragit® L100 and Gantrez MS-955 microparticles containing miconazole nitrate for oral delivery. Methods: Microparticles were prepared by spray-drying method to achieve high encapsulation efficiency and increase the drug solubility. The microparticles were formed containing 10% and 20% of drug on polymer Eudragit® L100 (E10 and E20), Gantrez MS-955 (G10 and G20) or their combination (EG10 and EG20). The influence of formulation factors (polymer:drug ratio, type of polymer) on yield percent, encapsulation efficiency, particle size, Fourier-transformed infrared spectroscopy (FTIR), X-ray diffraction, differential scanning calorimetry, in vitro drug release and antifungal activity were investigated. Results: Acceptable yield, micrometer-sized and drug-loading efficiencies higher than 89% were obtained. No change in FTIR assignments was recorded after the microencapsulation procedure. X-ray and differential scanning calorimetry studies revealed amorphous/non-crystalline formulations. Miconazole nitrate-microparticles provided a remarkable increase of dissolution rate of the drug. Miconazole nitrate and G10, G20 and EG20 microparticles fitted to biexponential kinetic model, and E10, E20 and EG10 microparticles, monoexponential kinetic model. The antifungal activity test demonstrated that miconazole nitrate-microparticles possessed the same anti-Candida albicans activity as the pure drug. Conclusion: These results indicate that miconazole nitrate-microparticles are feasible carriers for increased release of miconazole at oral environment.

Background: The study was aimed to enhance the mucoadhesive potential of Eudragit RS 100 and RL 100 using iron oxide. Methods: Microspheres of Eudragit RS/RL100, containing cinnarizine, were prepared by emulsification solvent evaporation technique employing 32 full factorial design. Eudragit RS or RL (X1) and iron oxide (X2) concentrations were the independent variables. Particle size, entrapment efficiency, mucoadhesion, zeta potential and t90% were the response variables. Microspheres when characterized by FTIR-ATR and DSC confirm entrapment of drug. Results: SEM analysis of microspheres exhibits roughness/micropores responsible for drug release. Particle size of Eudragit RS and Eudragit RL microspheres was found to increase from 275.60±2.68 to 438.72±22.73 nm and 283.14±1.95 to 475.55±29.66 nm. Incorporation of iron oxide increases zeta potential from 0.88±0.18 to 10.74±1.78 mV and 1.12±0.11 to 14.44±2.44 mV for Eudragit RS and RL microspheres, respectively. Highest mucoadhesion and zeta potential were obtained when 4.5% w/v of X1 and 20% w/v of X2 were used in the formulation of microspheres. Conclusion: The r2 values were significantly higher (P < 0.01) for the Langmuir equation as compared to Freundlich equation, indicating the involvement of electrostatic forces in the specific adsorption of mucin on to Eudragit microspheres. In vivo study indicates 2.5 to 3 times increased bioavailabity of cinnarizine through mucoadhesive microspheres.

Background: It is well known that the properties of polymers can be altered by exposure to γ- ray. γ-irradiation has been used as a sterilization method for polymeric drug delivery devices, and its drug release profile must not be significantly changed. In this study, the effect of γ-irradiation on the release profile of leuprolide acetate from PLGA-based in situ forming system was investigated. Methods: Poly(lactide-co-glycolide) (PLGA) was dissolved in N-methylpyrrolidinone (NMP) and irradiated with a total dose of 8 kGy γ-ray emitted by a 60Co source. Then, leuprolide acetate was added to the polymer solution. PLGA-based in situ forming systems were prepared by injecting some specific amount of prepared solution into a buffer phosphate pH 7.4 at 37 °C. The effects of γ-ray on drug release profiles, morphology of matrices and thermal properties as well as stability of polymer were evaluated. Results: The results showed that γ-irradiation causes a decrease in glass transition temperature (Tg) of PLGA from 43.4 to 38.1°C. A reduction in molecular weight of PLGA by about 17.8 % was found as consequence of radiolytic degradation. The morphological studies of PLGA matrices confirmed that the irradiated sample had higher porosity than the non-irradiated sample. It is found that the amount of released leuprolide acetate from irradiated matrix was increased by about 1.6 times after 33 days compared to the nonirradiated ones. In vitro drug release experimental data were fitted using the Gallagher- Corrigan model which indicated that diffusion and degradation were the predominant mechanisms of drug release. Conclusion: Accordingly, leuprolide acetate was released faster from the irradiated matrix compared to the non- irradiated matrix.

Background: Melanoma is known as the most dangerous form of skin cancer; whereas the malignant choroidal melanoma is an orphan disease known as the most common primary intraocular malignancy in adults. Literature suggests that the consumption of garlic and mistletoe leads to a reduced risk of developing cancer. Objective: The aim of this study was the obtaining and the characterization of polymer structures containing mistletoe or garlic extract. Methods: The structures were obtained in a polyaddition process combined with a spontaneous emulsification; they were characterized by pH, size, Zeta potential and DSC measurements, evaluation of encapsulation efficacy, penetrability through membranes and in vitro cytotoxicity tests. Results: The microstructures present sizes between 1.05 and 2.60 μm and Zeta potentials between -7 and +36 mV. A good encapsulation was observed on different evaluations (88-92%). It was determined that approx. 30% of polymer microstructures containing vegetal extracts pass through an artificial membrane in 4 days. An in vitro cytotoxicity test revealed that these products are safe for administration. The analysis of antitumor efficacy indicates that garlic extracts have important effects after 48 and 72 hours on A375 cells; however, polymer microstructures with herbal extracts did not reveal antiproliferative activities on A375 cells because these polymer structures present a slow degradation. Conclusion: Sterile eye drops solutions based on polymer microstructures containing garlic or mistletoe extracts were obtained; the sample based on garlic extracts may be used in the pharmaceutical field as drug carrier with an antiproliferative effect which occurs after a prolong period.

Objective: Low water solubility, high systemic toxicity and insignificant cellular uptake have limited efficient clinical applications of the anti-tumor agent Paclitaxel (PTX). To overcome these limitations, a Novel Nanostructured Lipid Carrier (NLC) modified with Folic Acid (FA) and polyethylene glycol (PEG) was prepared by emulsion solvent evaporation method using cholesterol, α-tocopherol, lecithin and Poloxamer. A partial factorial design was applied to determine the appropriate levels of variables for optimized formulation. Formulations were evaluated for Particle Size (PS), Zeta Potential (ZP), Entrapment Efficiency (EE), and release efficiency (RE72%). FA- and PEGconjugated octadecylamine (FA-ODA and PEG-ODA) were synthesized and confirmed by FTIR and H-NMR and incorporated either alone or in combination with the optimized formulation whose properties were also evaluated. PTX-loaded optimized, targeted, pegylated, targeted/pegylated NLCs, pure PTX, and Anzatax® along with their respective controls were selected for toxicity evaluation on human breast cancer cell line, MCF-7, using MTT assay. Methods: PS, ZP, EE%, and RE72% of the optimized formulation were 154.6 nm, -16.5 mv, 79.1% and 49.3%, respectively. Incorporation of α-tocopherol as the liquid lipid allowed for more efficient drug encapsulation, PS reduction, enhanced stability and sustained-release of the drug. Cytotoxicity of PTX-loaded NLCs modified with both FA-ODA and PEG-ODA was significantly enhanced compared to that of free PTX and other drug-loaded modified NLCs. Results and Conclusion: The results suggest that preparation of NLCs with synthesized conjugates might be a promising candidate for drug delivery of PTX to the cancerous cells and has a great potential as a carrier for tumor targeting in breast cancer.

Background: The present work describes the role of melt granulation and microenviron-mental pH modulation technique in solubility enhancement of a poorly water soluble NSAID, Aceclofenac (ACL). ACL is a BCS Class II drug showing dissolution rate limited absorption and pH dependent solubility, with higher solubility at alkaline pH. The limited solubility of ACL affects drug absorption and hence, therapeutic effect as the drug is indicated in conditions of pain where rapid onset of action is desired. Methods: Solubility enhancement of ACL was carried out by melt granulation technique using Gelucire 50/13 as molten carrier. The solubility of ACL was improved further by incorporating sodium hydrogen carbonate as pH modifier. The granules of ACL thus developed, were compressed into tablets using adsorbing carriers and other tableting excipients. Results: This dual approach not only enhanced ACL solubility but also aided in achieving a pH independent release. The developed tablets exhibited pH independent release as well as enhanced rate of dissolution which is indicated by in vitro dissolution studies and ex-vivo intestinal permeation studies. The pH independent release would ensure absorption of drug throughout the gastrointestinal tract. The solubility enhancement of ACL was further confirmed by characterization studies such as DSC and XRD. Conclusion: Thus, the dual approach of melt granulation and micro-environmental pH modulation can be simple and scalable method for solubility enhancement of poorly soluble drugs showing pH dependent dissolution rate limited absorption.

Background: The use of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) is not up to its potential because of their gastrointestinal side effects. Significant attention has been focused on the growth of bio-reversible derivatives, such as mutual prodrugs, to momentarily mask the acidic group of NSAIDs as a promising means of decreasing or eliminating the GI side effects. The aims of this paper are to synthesize the mutual prodrugs of selected NSAIDs (Ketorolac, niflumic acid, tolfenamic acid) with propyphenazone, a study on their several physicochemical characters, hydrolysis kinetics, antiinflammatory, analgesic activity and ulcerogenicity. Methods: Mutual prodrugs were synthesized and their structures were confirmed and characterized using IR, 1H NMR, 13C NMR, mass spectroscopy and their purity was established by elemental analysis. Synthesized prodrugs were subjected for pharmacokinetic studies, analgesic, anti-inflammatory activities and ulcerogenic index. Results: In vitro hydrolysis study of synthesized prodrugs in enzyme-free simulated intestinal fluid (SIF, pH 7.4) and 80% human plasma showed encouraging hydrolysis rate following first order kinetics while found stable in simulated gastric fluid (SGF, pH 1.2). Considerable decrease in ulcerogenic index and better anti-inflammatory activities were found in most of the cases as compared to their parent drugs. Among all prodrugs, viz. KE and NG showed excellent pharmacological response. A very less irritation to gastric mucosal was observed with the synthesized prodrugs than their parent drugs and can be considered for sustained drug release. Conclusion: Encouraging hydrolysis rate in SIF and 80% human plasma, improved analgesic and anti-inflammatory activities and reduced ulcerogenic liabilities of synthesized prodrugs revealed enhancement in the therapeutic index of the parent drugs. On the basis of above observation, it is concluded that mutual prodrugs approach can be applied to obtain synergistic effect for analgesic and anti inflammatory activities as well as to minimize gastrointestinal toxicity of the drug.