Sustained ophthalmic delivery of pH triggered Cromolyn sodium in situ gel

The research study intends to formulate pH triggered in situ gel of Cromolyn sodium composed of Polyacrylic acid (carbopol 934) polymer in combination with Hydroxypropyl Methylcellulose (HPMC K4M) polymer at 1:1, 1.5:1, 2:1 molar ratio by utilizing pH trigger method. Formulations were evaluated for pH, viscosity, gelling capacity, drug content and in vitro drug release. Results of Carbopol 934 and HPMC K4M based in situ gelling systems at 1:1, 1.5:1, 2:1 shown that the formulations were fluid state at room temperature in a formulated pH (pH 4.5) and went through fast progress into the viscous gel phase at the pH of the tear fluid 7.4. The viscosity of formulated pH triggered in situ gel at 2:1 molar ratio shown excellent result compares to 1:1, 1.5:1 molar ratio. The in vitro drug release of the developed in situ gelling formulations at 1:1, 1.5:1, 2:1 molar ratios increases the contact time and showed a non – fickian diffusion type of release behavior with 94.45%, 83.26%, 70.48% respectively over 8 hours periods compared with that of marketed formulation that shows 99.4% over 4 hours. Thus, the developed system at 2:1 molar ratio acts as a viable alternative to conventional eye drops and also prevent the rapid drainage.

Development, Optimization, and In Vitro Evaluation of Novel Oral Long-Acting Resveratrol Nanocomposite In-Situ Gelling Film in the Treatment of Colorectal Cancer

this study aimed to develop and evaluate sustained-release (SR) long-acting oral nanocomposites in-situ gelling films of resveratrol (Rv) to treat colorectal cancer. In these formulations, Rv-Soy protein (Rv-Sp) wet granules were prepared by the kneading method and then encapsulated in the sodium alginate (NA) dry films. The prepared nanocomposite in-situ gels films were characterized using dynamic light scattering, Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The optimized formulations were further evaluated based on drug encapsulation efficiency, pH-drug release profile, swelling study, and storage time effects. The optimized formulation was tested for its anticancer activity against colorectal cancer cells using the cytotoxicity assessment, apoptosis testing, cell cycle analysis, gene expression analysis, and protein estimation by the reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay methods, respectively. The optimum film showed encapsulation efficiency of 97.87% ± 0.51 and drug release of 14.45% ± 0.043 after 8 h. All physiochemical characterizations confirmed, reasoned, and supported the drug release experiment’s findings and the encapsulation assay. The Rv nanocomposite formulation showed concentration-dependent cytotoxicity enhanced apoptotic activity as compared to free Rv (p < 0.05). In addition, Rv nanocomposite formulation caused a significant increase in Bcl-2-associated protein X (Bax) and a decrease in expression of B-cell lymphoma 2, interleukin 1 beta, IL-6, and tumor necrosis factor-alpha (Bcl2, IL-1β, IL-6, and TNF-α respectively) compared to that of free Rv in HCT-116 cells. These results suggest that long-acting Rv nanocomposite gels could be a promising agent for colorectal cancer treatment.

A Recent Overview: In Situ Gel Smart Carriers for Ocular Drug Delivery

Delivery of the drug to the ocular area is blocked by the protective layers covering the eyes; it has always been a major problem to find effective bioavailability of the active drug in the ocular area due to the short duration of precorneal majority ocular stay. Direct delivery systems combine as well as oil, solution, and suspension, as a result, many delivery systems are not able to effectively treat eye diseases. Many works have been done and are being done to overcome this problem one of which is to use in-situ to build polymeric systems. Ocular In-situ gelling systems are a new class of eye drug delivery systems that are initially in solution but are quickly transformed into a viscous gel when introduced or inserted into an ocular cavity where active drugs are released continuously. This sol-to-gel phase conversion depends on a variety of factors such as changes in pH, ion presence, and temperature changes. Post-transplanting gel selects viscosity and bio-adhesive properties, which prolongs the gel's stay in the ocular area and also releases the drug in a long and continuous way unlike conventional eye drops and ointments. This review is a brief overview of situ gels, the various methods of in situ gelling systems, the different types of polymers used in situ gels, their gel-based methods, and the polymeric testing of situ gel. Keywords: In-situ gel, Polymers, and ion triggered in-situ gel, Mechanism, Evaluation parameters

Intranasal Administration as a Route to Deliver Drugs to the Brain (Review)

Introduction. Intranasal drug delivery from nose-to-brain is one of the promising approaches for the treatment of brain diseases including neurodegenerative diseases, stroke, brain tumors, etc.Text. Delivery of drugs through the nose has a number of advantages, including the rapid onset of a pharmacological effect, the ability to bypass the blood-brain barrier, avoidance of some side effects and fast and non-invasive route of administration. However, the significant disadvantages of this route are rapid elimination of the drug from the surface of the mucosal membrane, poor penetration of the drug through the nasal mucosa, mucociliary clearance and effects of proteolytic enzymes. Currently, to overcome the above limitations, various approaches are used, including the development of delivery systems from nose-to-brain, which are mucoadhesive, mucus-penetrating and gel-forming systems that facilitate the retention or penetration of drugs through the mucosal membranes. At the same time, high-molecular weight compounds play a significant role in the design of these systems. In particular, mucoadhesive systems can be prepared from cationic and anionic polymers. Recent studies have also shown that interpolyelectrolyte complexes also exhibit mucoadhesive properties. An improvement in mucoadhesive properties of polymers can also be achieved by conjugating various functional groups such as thiols, maleimides, acrylates, methacrylates, catechols, etc. Mucus-penetrating systems can be prepared by PEGylation of nanoparticles, as well as functionalization with some poly(2-oxazolines), polyvinyl alcohol, etc. The mucus-penetrating ability of these polymers has been shown in other mucosal membranes in the body. Finally, increased penetration can be achieved by using mucolytic agents in combination with non-ionic surfactants. Another approach to increase the efficiency of drug delivery from nose-to-brain is the use of in situ gelling systems. Initially, this type of formulation exists as a solution; then a phase transition to gel is observed in response to chemical and physical effects. Depending on the external stimulation of the phase transition, thermo-, pH-, ion-reversible and other systems are known. These systems have shown effectiveness for delivery to the brain by intranasal administration.Conclusion. Effective intranasal delivery of drugs and therapeutic agents to the brain can be achieved by using mucoadhesive, mucus-penetrating, gelling systems and/or their combinations.

Thermosensitive Polyester Hydrogel for Application of Immunosuppressive Drug Delivery System in Skin Allograft

Tacrolimus (FK506) is a common immunosuppressive drug that is capable of suppressing acute rejection reactions, and is used to treat patients after allotransplantation. A stable and suitable serum concentration of tacrolimus is desirable for better therapeutic effects. However, daily drug administration via oral or injection routes is quite inconvenient and may encounter drug overdose or low patient compliance problems. In this research, our objective was to develop an extended delivery system using a thermosensitive hydrogel of poly ethylene glycol, D,L-lactide (L), and ϵ-caprolactone (CL) block copolymer, mPEG-PLCL, as a drug depot. The formulation of mPEG-PLCL and 0.5% PVP-dissolved tacrolimus was studied and the optimal formulation was obtained. The in vivo data showed that in situ gelling is achieved, a stable and sustained release of the drug within 30 days can be maintained, and the hydrogel was majorly degraded in that period. Moreover, improved allograft survival was achieved. Together, these data imply the potential of the current formulation for immunosuppressive treatments.