Current Drug Delivery - Volume 19, Issue 6, 2022

Cubosomes are bicontinuous cubic phase nanoparticles with a size range from 10-500 nm. They offer various advantages with some limitations at the production level, e.g., cubosomes have the feature to encapsulate a large amount of the drug due to its large internal area owing to cuboidal shape but limited in large scale production due to its high viscosity which is associated with the problem in homogenization. This nanoparticulate formulation is compatible for administration by various routes like oral, transdermal, topical, buccal, etc. The drug release mechanism from cubosomes was reported to be dependent on the partition coefficient and diffusion process. Compared with liposomes, cubosomes show many differences in various aspects like shape, size, ingredients, and mode of action. The main ingredients for the preparation of cubosomes include lipids, stabilizers, aqueous phase and therapeutic agents. Several methods have been reported for cubosomes, including the top-down method, the bottom-up method and the adopted coarse method. For the optimization of cubosomes, the key factors to be considered, which will affect the cubosomes characteristics include the concentration of lipid, temperature and pH. At present, many research groups are exploring the potential of cubosomes as biosensors and nanocarriers. Based on the latest reports and research, this review illuminates the structure of the cubosomes, mechanism of the drug release, different methods of preparation with factors affecting the cubosomes, application of cubosomes in different sectors, differences from the liposomes, and their advantages.

The conventional drug delivery systems have a long list of repeated dosing and toxicity issues. The hydrogels solve these issues as they minimize such activities and optimize therapeutic benefits. The hydrogels possess tunable properties that can withstand degradation, metabolism, and control release moieties. Some areas of applications of hydrogels involve wound healing, ocular systems, vaginal gels, scaffolds for tissue and bone engineering, etc. They comprise about 90% of the water that makes them suitable bio-mimic moiety. Here, we present an extensive review of various perspectives of hydrogels, along with their applications.

Background: Colorectal cancer (CRC) is the third most common cancer in the world. 5- Fluorouracil (5-FU) is a conventional and most effective drug used in the clinic for the treatment of CRC. However, the clinical use of 5-FU is limited due to the acquired resistance and systemic toxicity, such as hepatotoxicity and gastrointestinal toxicity. Objective: Recent advances in nanomedicine are being exploited to develop nanoparticle platforms to overcome resistance and therapeutic delivery of active molecules. Here, we developed 5-FU loaded sulfadiazine-poly(lactide-co-glycolide) nanoparticles (SUL-PLGA NPs) to be applied in the colorectal cancer model. Methods: We assessed the in vivo efficacy of the SUL-PLGA NPs to enhance the antitumor effect of 5-FU. Results: In vivo treatment with 5-FU-SUL-PLGA NPs significantly reduced tumor growth in a colon cancer xenograft model compared to free 5-FU and 5-FU loaded non-targeted NPs. Treatment with 5-FU-SUL-PLGA NPs also increased blood vessel diameters within tumors, which could act in conjunction to enhance antitumor efficacy. In addition, 5-FU-SUL-PLGA NPs significantly reduced liver mass and lung mass, which are the most common metastasis sites of CRC, and decreased liver hepatotoxicity compared to free 5-FU drug and 5-FU loaded non-targeted NPs. Conclusion: Our findings suggest that the use of 5-FU-SUL-PLGA NPs is a promising strategy to enhance 5-FU efficacy against CRC.

Objective: The objective of the present study was to design novel colon targeted delivery of Dicyclomine Hydrochloride (DCH) microsponges. Methods: Microsponges (MS1-MS4) based on different ratios of Hydroxypropylmethylcellulose (HPMC) and DCH were prepared by quasi-emulsion solvent diffusion method. Micro-sponges were analyzed by determining percent yield, encapsulation efficiency, drug content, drug-polymer compatibility and thermal stability. Kinetic analysis of thermal stability data was done by Chang method, Friedman method and Broido method. In vitro dissolution study was carried out at pH 1.2, pH 6.8 and pH 7.4 at different time intervals. Results: Results showed that there was no chemical interaction between DCH and HPMC in all microsponge formulations. Production yield, drug content and encapsulation efficiency were enhanced on increasing the drug-polymer ratio. Thermal stability of all the micro-sponges was greater than that of pure drug. In vitro drug release was decreased on increasing the polymer concentration at different pH levels. The newly prepared micro-sponges based on HPMC were confirmed as a promising means of colon-targeted delivery of DCH. An HPLC method was developed and validated for the bioequivalence study of newly designed microsponges. Pharmacokinetics parameters were calculated using the linear trapezoidal method after single oral administration of microsponges in white albino rabbits. Pharmacokinetics results indicate an enhancement in the value of t1/2, tmax, Cmax and AUC0-t of DCH in the microsponges as compared to standard DCH showing enhanced bioavailability of the drug after microsponges formation. Conclusion: The current study shows a new approach for colon-specific delivery of DCH based on microsponges.

Background: Graphene nanoribbons are nanosized strips of graphene with unique physicochemical properties like higher drug loading capacity and affinity for tumor cells. Objective: The principal objective of this research was to develop oxidized graphene nanoribbons (O-GNRs)-based delivery system for cisplatin against non-small cell lung carcinoma cell line A549 by selective endocytosis. Methods: The O-GNRs prepared using various synthetic steps like oxidative unzipping were evaluated for various parameters like morphology, Fourier Transform Infrared (FTIR) study, % adsorption efficacy, Differential scanning colometric (DSC) study and in-vitro efficacy studies. Results: Graphene nanoribbons with the length of 200-250 nm and width of 20-40 nm were obtained. The FTIR spectrum of drug-loaded O-GNRs exhibited a characteristic peak at 1550 cm-1 (- N-H group) of cisplatin. The DSC indicated the presence of sharp endothermic peaks at 59°C (PEG), 254°C (-C-NH3) and 308.6°C (-C-Pt). The % adsorption efficiency was found to be 74.56 ± 0.798% with in-vitro release in controlled manner (63.36% ± 0.489%) for 24 h. Conclusion: The nanoformulation showed an average inhibition of 22.72% at a lower dose of cisplatin (> 25%) by passive targeting on cell line A549 by DNA alkylation. In the near future, graphene-based systems will establish potential nanosystems in cancer treatment due to the additive effect of graphene with various therapeutic agents.

Background: Arctostaphylosuva-ursi(AUU) being rich in polyphenols and arbutin is known to have promising biological activities and can be a potential candidate as a cosmaceutical. Ethosomes encourage the formation of lamellar-shaped vesicles with improved solubility and entrapment of many drugs including plant extracts. Objective: The objective of this work was to develop an optimized nanostructured ethosomal gel formulation loaded with AUU extract and evaluated for skin rejuvenation and depigmentation. Methods: AUU extract was tested for phenolic and flavonoid content, radical scavenging potential, reducing power activity, and in-vitro SPF (sun protection factor) estimation. AUU loaded 12 formulations were prepared and characterized by SEM (Scanning Electron Microscopy), vesicular size, zeta potential, and Entrapment Efficiency (%EE). The optimized formulation was subjected to noninvasive in-vivo investigations after incorporating it into the gel system and ensuring its stability and skin permeation. Results: Ethosomal vesicles were spherical in shape and Zeta size, zeta potential, PDI (Polydispersity Index), percentages of EE and in-vitro skin permeation of optimized formulation (F3) were found to be 114.7nm, -18.9mV, 0.492, 97.51±0.023%, and 79.88±0.013% respectively. AUU loaded ethosomal gel formulation was stable physicochemically and exhibited non-Newtonian behavior rheologically. Moreover, it significantly reduced skin erythema, melanin as well as sebum level and improved skin hydration and elasticity. Conclusion: A stable AUU based ethosomal gel formulation could be a better vehicle for phytoextracts than conventional formulations for cosmeceutical applications such as for skin rejuvenation and depigmentation.

Purpose: Traditional dosage forms of granisetron (GRN) decrease patient compliance associated with repeated drug administration because of the short half-life of the drug. Methods: In this study, novel GRN-loaded Polylactic-co-glycolic Acid (PLGA) sustained-release microspheres were prepared for the first time via a dropping-in-liquid emulsification technique. The effects of various factors, such as pH of the outer phase, Tween 80, Polyvinyl Alcohol (PVA) concentrations, and hardening process, on the Encapsulation Efficiency (EE), Drug Loading (DL), and particle size of microspheres were extensively studied. The physicochemical properties, including drug release, surface morphology, crystallinity, thermal changes, and molecular interactions, were also studied. Results: GRN has a pH-dependent solubility and it exhibits a remarkably high solubility under acidic condition. The EE of the alkaline medium (pH 8) was higher than that of the acidic medium (pH 4.0). EE and DL decreased in the presence of Tween 80 in the outer phase, whereas EE significantly increased during hardening. The particle size of microspheres was not affected by PVA and Tween 80 concentrations, but it was influenced by PVA volume and hardening. X-ray diffraction and differential scanning calorimetry results showed that the physical state of the drug changed from a crystalline form to an amorphous form, thereby confirming that the drug was encapsulated into the PLGA matrix. Fourier transform-infrared spectroscopy confirmed that some molecular interactions occurred between the drug and the polymer. GRN-loaded PLGA microspheres showed sustained release profiles of over 90% on week 3. Conclusion: GRN-loaded PLGA microspheres with sustained-release were successfully prepared, and they exhibited a relatively high EE without Tween 80 as an emulsifier and with the hardening process.