The paper aimed to progress an ideal gastro retentive drug delivery system intended for directing Losartan and Hydrochlorothiazide as a fixed-dose combination for anti-hypertensive therapy. The bilayer tablets were primed through direct compression method. Losartan was formulated by means of a floating layer expending hydrophilic swellable polymer Hydroxy Propyl Methyl Cellulose K4M, ethyl cellulose (4cps) as a buoyancy enhancer, sodium bicarbonate as a gas spawning agent. The amount of polymer blends remains optimized using 23 full factorial designs. The clout of experimental factors such as swelling agent concentration, buoyancy enhancer and gas generating agent on floating lag time, total floating time, T50% and % drug release remain investigated to get optimized formulation. The responses remain analyzed using Analysis of variance, and polynomial equation stood created for every retort using Multiple linear regression analysis. Entirely preparations floated for more than 12 h. The release pattern of losartan stood fitted to diverse models based on the coefficient of correlation (r). All the formulations, except F2, showed the Korsemeyer-Peppas model as the best fit model. Formulation F2 showed the zero-order model. Diffusion exponents (n) remained indomitable designed for entirely formulations (0.45–0.89), accordingly the chief drug discharge mechanism was non-fickian (anamolous) transport. Formulation F4 containing 20% w/w Hydroxy Propyl Methyl Cellulose K4M, 15% Sodium bicarbonate and 5% ethyl cellulose (4cps) was the best formulation as per the range of drug release remain institute to be more than 95 % in 12h and floating lag time was 20.15 s. The immediate-release layer stood optimized using crospovidone and Indion 414 as a super disintegrant. Formulation A8 containing 2% Indion 414 was considered as optimized formulation as it released 99% drug within 35 min and possessed less disintegration time. Optimized formulation F4 from the controlled-release layer and A8 from immediate-release layer was used to formulate bilayer tablet. The optimized formulation was imperilled to stability reading for three months at 40○C/75% relative humidity. The stability revision exhibited no substantial alteration in the appearance of tablets, floating characteristics, drug content and in-vitro drug dissolution. Consequently, a biphasic drug release design was effectively accomplished over the formulation of floating bilayer tablets.

The contemporary research implicates the formulation and evaluation of a thermosensitive in situ nano gelling method to improve solubility and ocular residence time of flurbiprofen. This study was carried out in two phases. In the first phase, an insolubility drug has been formulated in the form of a nanoparticulate system and evaluated for its characteristics. The nanoparticles obtained demonstrated an average size array of 150 to 250 nm in diameter, up to 79.35% encapsulation efficiency, and up to 93.42% drug release throughout 2 h. In the second phase, nanoparticulate systems were dispersed in aqueous solutions of Pluronic F 127 (14%) and various concentrations of Carbopol 934 in combination to form an in situ nano gel. The prepared in situ gel was investigated for its physicochemical properties like pH, flowability, sol-gel transition temperature, gelling capacity, and rheological properties. Carbopol 934 did not significantly affect sol-gel transition temperature in optimized concentration (< 0.3%) but altered gelling capacity, pH, and transparency of the formulations. In vivo resident time and eye irritation test was evaluated in the rabbit eye. In optimized in situ gelling formulation (NIGF3), approximately 95% of in vitro drug release was observed after 6 h. NIGF3 increased precorneal residence time and high concentration in aqueous humor when paralleled to flurbiprofen eye drops. Greater concentration of drug in aqueous humor was due to its improved saturation solubility of the drug, and amplified residence time was attributed to the formation of gel matrix-embedded nanoparticles. This demonstrated that in situ nano gels (NIGF3) comprehending aqueous solutions of 0.3% w/v concentrations of Carbopol 934 with Pluronic F 127 may ominously persist the residence time and mend bioavailability of a water-insoluble drug. Graphical abstract

Nanogels are cross-linked, nano-sized hydrogels with dimensions ranging from 20 to 200 nm. Nanogel-based nanoplatforms have proven to be an excellent choice for pharmaceutical formulations. Nanosystems have properties that are very useful in polymeric drug delivery applications, and their particular strength is that they have these nanosystemic properties and can thus merge with polymeric materials. Drug-carrier size is designed to be nano-sized in order to maintain optimal stability, resulting in more surface area and interior space. This also allows for a prolonged period of time for loaded pharmaceuticals to circulate. They can be classified by stimuli responsive or non-responsive behavior and type of linkages present in the network chains of gel structure. Nanogel can be synthesized by Photolithographic, modified pullulan, emulsion polymerization reverse microemulsion polymerization inverse miniemulsion polymerization and free radical crosslinking polymerization technique. Hybrid nanogels are different from conventional polymer nanoparticles often employed for drug administration. They can encapsulate bioactive medicines and regulate the release of such medications over time and in particular areas. The hybrid nanogels used to create a specific form of the hybrid, especially one geared towards increasing targeted drug delivery, enhance the effectiveness of ailment treatments, but perhaps the introduction of a multifunctional nanogel-based drug delivery system. Graphical Abstract