Current Nanomedicine - Volume 8, Issue 2, 2018

Background: Nanocarriers have been a part of drug delivery for some decades now. Due to the enormous advantages offered by them, they are replacing the conventionally available systems. Objective: The objective of the current review is to focus wider applications of these nanocarriers in drug delivery, diagnosis, imaging, and targeting as well. It also focuses on the different types of nanocarriers, method of preparation, characterization and most advanced uses or application in medicine. Methods: Literature has been reviewed intensely. Data from various sources like NCBI PubMed and other valued journals have been reviewed thoroughly. Various research investigations related to nanocarriers systems have been compiled. Results: Selection of the nanocarriers type as well as their composition depends upon the disease and the application for which it is to be used. Nanocarriers have been investigated for various diseases such as cancer drug delivery, cardiovascular drug delivery, insulin delivery, antimalarial drug delivery, central nervous system drug delivery, ophthalmic, pulmonary and brain delivery, etc. Conclusion: Nanotherapy has led to the advancement in the delivery of chemotherapeutic drugs in cancer because of their characteristic enhanced permeation and retention in the tumor tissue. Also, its applications in various other aspects of therapeutics have been extraordinary and much more is yet to be explored.

Objective: The aim of the present work is to prepare Mefenamic acid nanoparticles by Nanoprecipitation technique. Two different polymers were used namely Ethyl cellulose and Eudragit S-100 to study the effect of polymers on the release rate of the prepared formulation. The process parameters such as stirring rate, %surfactant (w/v), drug to polymer ratio and so forth were optimized. Methods: Nanoprecipitation technique was employed in which drug and polymer were dissolved in an organic solvent and added drop wise to 0.4% (w/v) Poly Vinyl Alcohol aqueous solution under continuous magnetic stirring. After 5hrs, the solvent was removed by means of rotary evaporator to collect amorphous nanoparticles. For each polymer, total five formulations were prepared by varying the concentration of drug and polymer. Results: The prepared nanoparticles were then characterized for drug-polymer interaction study, mean particle diameter, stability, and surface morphology and evaluated for drug content, entrapment efficiency, loading capacity, and in-vitro drug release. After evaluating the parameters the best formulation was found to be F3 formulation of ethyl cellulose with drug content of 94%, drug entrapment efficiency of 92.2%, loading capacity of 32.6%, mean particle diameter of 132.8nm and zeta potential value of -42.8mV. FTIR spectrum revealed no drug-polymer interaction and in-vitro drug release data showed 90.22% of drug release sustained up to 12hrs. Conclusion: Ethyl cellulose was found to be the better polymer for the preparation of Mefenamic acid nanoparticles by Nanoprecipitation technique. Because of the mean particle diameter, excellent stability, higher drug entrapment efficiency and drug loading capacity.

Background: The need for parenteral administration of arteether (ART) as intramuscular (IM) injection for three consecutive days often proves a major constraint for patient compliance. The present study reports development of an in situ IM implant to provide sustained release of ART over 72h. Objective: The development of self microemulsifying drug delivery system (SMEDDS) based lyotropic liquid crystalline preconcentrates (LLCPr) comprising oil, surfactant and cosurfactants with a biodegradable polymer (P-LLCPr) which undergo rapid transition to liquid crystalline phase (LCP) to form an in situ gel following IM injection. Methods: The P-LLCPr was prepared by mixing oil and surfactant. PLGA was dissolved in cosurfactant, added to this blend and vortex was mixed. The LLCPr (without polymer) and P-LLCPr were evaluated for conversion into LCP by polarization optical microscopy (POM), XRD, gel strength, particle size, zeta potential and sustained release by ex vivo method in muscle of G. domesticus. Results: POM and XRD study confirmed the formation of anisotropic LCP. A force of <25N revealed good injectability of the LLCPr and P-LLCPr in vitro, and ex vivo in the extensor digitorum longus (EDL) muscle of G. domesticus. Implant formation was observed both in vitro and ex vivo. The P-LLCPr formed a stiff gel which exhibited a 4 fold enhancement in gel strength compared to LLCPr. The particle size of P-LLCPr was 120 ± 1.5nm and zeta potential -14.56 mV. The ex vivo release method in EDL muscle, developed to mimic in vivo conditions revealed 100% release in <24 h from ART solution and LLCPr. The P-LLCPr however exhibited sustained release of ART for >48h. Conclusion: The sustained release P-LLCPr of ART suggests great promise as a single shot therapy for the treatment of malaria with enhanced patient compliance.

Background: When localized in cells, gold nanoparticles (GNPs) enhance absorption of ionizing radiation and hence biological damage. They have the potential to increase the efficiency of radiotherapy cancer treatment. Objective: To investigate the dose enhancement and biomolecular radiosensitization induced by ultra-stable polyvinyl alcohol coated gold nanoparticle (PVA-GNPs). Methods: The dose enhancement induced by PVA-GNPs was quantified by Fricke chemical dosimetry. The absorbed dose as a function of PVA-GNP concentration for irradiation with 80 and 100 kVp X-rays and 60Co γ-rays. The efficiency of PVA-GNPs to sensitize plasmid DNA to 80 kVp X-rays was measured by gel electrophoresis for a water solution of PVA-GNPs and DNA in a 1:1 ratio. Subcellular localization and the radiosensitization of PVA-GNPs in F98 glioma cells was performed. Results: Under X-ray irradiation, the absorbed dose increased with PVA-GNP concentration. Average dose enhancements were 1.89 ± 0.14 and 2.25 ± 0.11 for 80 and 100 kVp X-rays, respectively, which led to an increase in DNA strand breaks and interduplex crosslinks. Conversely, no significant dose enhancement was found with 60Co γ-rays (P = 0.77). PVA-GNPs accumulated near the nuclear membrane and in vesicle-like structures in the cytoplasm, but did not localize in the nucleus. The induction of radioenhancement by 2-fold was observed when combined 500 nM PVA-GNPs with 4 Gy X-rays. Conclusion: Radiosensitization by PVA-GNPs was observed under 80 and 100 kVp Xray irradiation. These results support the potential application of these highly stable nanoparticles to enhance the benefits of low-energy X-ray radiotherapy in cancer treatments.

Background: Despite the advancement in the development of newer anti-HIV drugs, various drawbacks still persist with antiretroviral therapy. Therefore, this study was conducted to overcome the pharmacokinetic limitations of commonly prescribed anti-HIV drugs with the implication of nanotechnology. Objectives: • Formulation of nanoparticles carrying antiretroviral drugs. • Pharmacokinetic and pharmacodynamic study of nanoparticles loaded with antiretroviral drugs viz zidovudine (AZT), didanosine (ddI), and ritonavir (RTV). • Ex vivo study of nanoparticles loaded with antiretroviral drugs. Methods: Poly (lactide-co-glycolide) (PLGA) nanoparticles encapsulating AZT, ddI and RTV were developed by multiple emulsion solvent evaporation technique and characterized for size, shape, zeta potential, polymer drug interaction etc. Comparative pharmacokinetic studies were carried out following single oral dose administration of free or nano drugs in mice. Results: PLGA nanoparticles loaded with HIV drugs were found to be stable and in nanorange. FTIR images of ddI and RTV did not show any interaction of these drugs with polymer except for AZT. The absence of any sharp diffraction peaks in the XRD of encapsulated drugs indicated complete amorphization of drugs in nanoparticles. The pharmacokinetic parameters were significantly improved upon nanoencapsulation as compared to the parent drugs. Fluorescent nanoparticles were found to be efficiently taken up by peritoneal macrophages and cytotoxicity assay indicated that PLGA nanoparticles are safe to be used as drug delivery system. Conclusion: PLGA nanoparticles exhibited sustained release of AZT, ddI and RTV in mice with improved pharmacokinetic parameters and hold great prospective for extended research in higher animals.

Background: Nanotechnology is steering mankind into new realms of efficient and miniature tools and gadgetry. The development of reliable, eco-friendly synthesis of nanomaterials is always an important aspect of nanotechnology. Silver nanoparticles have been used extensively as an antimicrobial agent and various products comprising of silver nanoparticles are accessible to the household. Method: The aim of this study was to formulate an effective, stable nanoherbal antimicrobial cream and used topically in order to treat all type of skin infection. Therefore, here we have reported herbal based biosynthesized silver nanoparticles using Martynia annua (Bichu) herbal extract with an average particle size of 6 nm under ambient conditions. Structural investigations were examined by selected area electron diffraction (SAED) and powder XRD depicted perfectly crystalline nature of the particles. Results: The obtained results confirmed that the Martynia annua (Bichu) extract is a good bioreductant for the synthesis of silver nanoparticles. The synthesized silver nanoparticles showed inhibition and had significant antibacterial activity against human pathogens gram-negative bacterial strains (Klebisella pneumoniase, Enterobcter cloacae, Pseudomonas aeroginosa and Escherichia Coli.)”. Conclusion: These nanoparticles were employed as broad-spectrum antibiotics, after using in herbal based nanocream. Further, various physicochemical parameters of nanoherbal cream were measured.

Objective: The aim of the present investigation entails the development and optimization of self-microemulsion preconcentrates for improving the solubility and oral bioavailability of aprepitant. Methods: Preconcentrate ingredients, i.e. oils, surfactants and co-surfactants were selected on the basis of equilibrium solubility studies. Ternary plots were constructed to determine stable microemulsion regions and determine optimized concentration ranges for robust preconcentrate formulations of aprepitant. Various characterization parameters were studied to investigate the optimized formulation having desired attributes of SMEDDS. Dissolution and pharmacokinetics studies were conducted to determine the release rate and oral bioavailability, respectively. Results: The optimized formulation containing 7.14%w/w of Lauroglycol FCC, 36.14 %w/w of Labrasol and 32.14%w/w of Transcutol P exhibited optical birefringence and resulted in thermodynamically stable nano-particulate emulsion. TEM revealed morphological behavior with nano-structured globules having negligible aggregation. The optimized liquid SMEDDS were converted into solid form by spray drying and showed physical compatibility in FTIR and confirmed its amorphous state in XRD pattern. SEM revealed spherical particles having colloidal nature with uniform size distribution. In vitro release studies of optimized solid preconcentrates showed multi folds augmentation in release behavior and statistical significance (P<0.05) as compared with marketed product. In vivo pharmacokinetics in male wistar rats demonstrated statistically (P<0.05) enhanced AUC0-24h and Cmax as compared with API and marketed product. Accelerated stability studies signify high stability of the robust formulation at one month storage period of time. Conclusion: The present investigation judiciously extrapolated the immense potential of SMEDDS in enhancing the solubility and oral bioavailability of poorly water-soluble anti-emetic drug aprepitant.