Formulation and investigation of pilocarpine hydrochloride niosomal gels for the treatment of glaucoma: intraocular pressure measurement in white albino rabbits

The present study was focused on investigating niosomal gels loaded with cholinergic drug; pilocarpine HCl, for prolonged precorneal residence time and improved bioavailability for glaucoma treatment. Pilocarpine HCl niosomes were prepared using various nonionic surfactants (span 20, span 60 and span 80), in the presence of cholesterol in different molar ratios by ether injection method. The selected formulations were incorporated into carbopol 934 and locust bean gum-based gels. TEM analysis confirmed that niosomes formed were spherical in shape and has a definite internal aqueous space with uniform particle size. Formulation F4 composed of span 60 and cholesterol (1:1) gave the highest entrapment (93.26 ± 1.75%) and slower release results after 8 hours (Q8h = 60.35 ± 1.87%) among other formulations. The in-vitro drug permeation studies showed that there was a prolonged release of drug from niosomal gels as compared to niosomes itself. Considering the in-vitro drug release, niosomal gel formulation G2 was the best among the studied formulations. The release data were fitted to an empirical equation, which indicated that the release follows non-Fickian diffusion mechanism. The stability study revealed that incorporation of niosomes in gel increased their stability than the niosome itself. No signs of redness, inflammation, swelling or increased tear production were observed over the study period for tested formulation by Draize's test. The intraocular pressure (IOP) lowering activity of G2 formulation showed relative bioavailability 2.64 times more than bioavailability of marketed Pilopine HS® gel. These results suggest that the niosomal gels containing pilocarpine HCl are promising ocular carriers for glaucoma treatment.

Methotrexate in the Treatment of Psoriasis and Rheumatoid Arthritis: Mechanistic Insights, Current Issues and Novel Delivery Approaches

Our review is focused on the use of methotrexate in drug therapy of two autoimmune diseases, psoriasis and rheumatoid arthritis (RA). The article describes the pathogenesis of psoriasis and RA, the role of methotrexate in the treatment of these diseases with more focused review on the mechanism behind the clinical benefits of methotrexate therapy. Methotrexate due to its cytotoxic, anti-inflammatory and immune modulatory activities provides clinical benefits in the therapy of the selected diseases. This review also gives a panorama of the problems associated with the use of methotrexate in the selected diseases and the guidelines provided by FDA for its safe use. The novel colloidal drug delivery systems of methotrexate, with particular emphasis on advantages offered by liposomal formulation, niosomal gel, hydrogel, albumin conjugates, nanoparticles and nano structured lipid carriers in psoriasis and RA are also reviewed. It seemed that the use of newer colloidal carriers with improved skin permeability by minimizing its systemic availability will be a useful strategy to reduce the toxic effects of the drug in psoriatic patients. In rheumatoid arthritis patients, the development of newer therapeutic strategies using appropriate targeting ligands that specifically deliver the drug to the inflamed joint space will help to overcome its toxic effects by minimizing the systemic exposure.

Growth Factor-Loaded Nano-niosomal Gel Formulation and Characterization

Controlled delivery of signaling factors could be a great approach in the tissue engineering field. Nano-niosomal drug delivery systems offer numerous advantages for this purpose. The present study reports the formulation and evaluation of a growth factor (GF)-loaded nano-niosome-hydrogel composite for GF delivery to modulate cell behavior. Niosomes were prepared, using span 60 surfactant with cholesterol (CH) in diethyl ether solvent, by reverse-phase evaporation technique. Basic fibroblast growth factor (bFGF) and bovine serum albumin (BSA) were loaded simultaneously and the final suspension was embedded into agarose hydrogel. Particle size, vesicle morphology, protein entrapment efficiency (EE), and release profile were measured by dynamic light scattering (DLS) nanoparticle size analyzer, transmission electron microscopy (TEM) and NanoDrop spectrophotometry methods, respectively. The release and performance of bFGF were revealed via human umbilical vein endothelial cell (HUVEC) proliferation using microscopy imaging and MTT assay. Nano-niosomes had an average particle size of 232 nm and had encapsulated 58% of the total proteins present in the suspension. bFGF-BSA-loaded niosomal gel considerably enhanced HUVEC proliferation. This GF-loaded niosomal hydrogel could be a potent material in many biomedical applications including the induction of angiogenesis in tissue engineering.

Niosomally encapsulated silver sulfadiazine gel for burn treatment

Silver sulfadiazine (SSD) is the antibacterial of choice for the treatment of burn. The current marketed formulation of SSD is 1% w/w water soluble cream, which requires frequent applications, which is very painful to patients. Niosomes were prepared by a thin film hydration method. The in vitro antimicrobial efficiency of niosomal SSD (18 ± 0.5 mm) was as good as that of marketed cream (17 ± 0.5 mm) against Staphylococcus aureus even when used in half the concentration (0.5%) of marketed cream (1%). Further SSD (0.5% w/w) niosomal gel was prepared using 1.6% carbopol 934. It was evident through in vitro permeation studies that SSD release was considerably retarded from both niosomes and niosomal gel in comparison with marketed cream thereby decreasing the dosing frequency. In-vivo study demonstrated that a niosomal gel containing 0.5% w/w SSD was more effective in burn wound healing compared to 1% w/w marketed cream even when applied once a day.

Transdermal delivery of meloxicam using niosomal hydrogels: in vitro and pharmacodynamic evaluation

Non-ionic surfactant vesicles were prepared using Span-60 and cholesterol in the mass ratios of 1:1, 2:1, 1:2 and 3:1 for transdermal delivery of an anti-inflammatory drug meloxicam (MXM). The drug encapsulation efficiencies and particle size were observed in the range of 32.9-80.7% and 56.5-133.4 nm, respectively. Three different gel bases were also prepared using Poloxamer-407, Chitosan and Carbopol-934 as polymers to study the performance of the in vitro release of the drug. Prepared gels were also converted into niosomal gels. In vitro release characteristics of MXM from different gels were carried out using dialysis membrane in phosphate buffer (pH 7.4). The poloxamer-407 gel or niosomal poloxamer-407 gel showed the superior drug release over the other formulations. The release data were treated with various mathematical models to assess the relevant parameters. The results showed that the release of MXM from the prepared gels and niosomal gels followed Higuchi's diffusion model. The flux of MXM was found to be independent on the viscosity of the formulations. The anti-inflammatory effects of MXM from different niosomal gel formulations were evaluated using carrageenan-induced rat paw edema method, which showed superiority of niosomal gels over conventional gels.