Factorial design of in situ gelling two-compartment systems containing chlorhexidine for the treatment of periodontitis

In vitro and in vivo evaluation of in situ forming polyester implants for the extended release of carvedilol

Polyester based in situ forming implants (ISFIs) are injectable long-acting drug delivery systems that offer a wide range of unique advantages. As a result of these advantages, two relatively high molecular weight, ester terminated grades of poly (D,L-lactide-co-glycolide) (PLGA) and poly(D,L-lactide) (PLA) were evaluated for their ability (i) to form ISFIs loaded with carvedilol, and (ii) to control its release both in vitro and in vivo. At a polymeric concentration of 40% w/w, implant solutions were syringeable, injectable, and able to encapsulate carvedilol to a high degree (encapsulated drug% > 97%). When visualized using scanning electron microscopy (SEM), implants were found to have a dense thin surface atop porous sublayers. As for their in vitro evaluation, PLGA and PLA implants were able to maintain drug release over the course of 49 and 84 days, respectively. On the other hand, in vivo drug release from both implants was almost identical and lasted for only 42 days. This may be due to the overriding effect of the similar host environment at the injection site that diminished the effect of polymeric physiochemistry on phase inversion and drug release. Lastly, while the polymer-free drug/NMP solution completely released its drug content within the initial half hour in vitro, the formulation extended drug release in vivo. This could be due to a yet to be investigated interaction between carvedilol and NMP under in vivo conditions. These results cement the significance of formulating carvedilol loaded ISFIs for the management of chronic conditions.

Optimizing Antioxidant Potential: Factorial Design-Based Formulation of Fucoidan and Gallic Acid-Conjugated Dextran Blends

The role of oxidative stress in health and homeostasis has generated interest in the scientific community due to its association with cardiovascular and neurodegenerative diseases, cancer, and other diseases. Therefore, extensive research seeks to identify new exogenous antioxidant compounds for supplementation. Polysaccharides are recognized for their antioxidant properties. However, polysaccharide chemical modifications are often necessary to enhance these properties. Therefore, dextran was conjugated with gallic acid (Dex-Gal) and later combined with fucoidan A (FucA) to formulate blends aimed at achieving superior antioxidant activity compared to individual polysaccharides. A factorial design was employed to combine FucA and Dex-Gal in different proportions, resulting in five blends (BLD1, BLD2, BLD3, BLD4, and BLD5). An analysis of surface graphs from in vitro antioxidant tests, including total antioxidant capacity (TAC), reducing power, and hydroxyl radical scavenging, guided the selection of BLD4 as the optimal formulation. Tests on 3T3 fibroblasts under various conditions of oxidative stress induced by hydrogen peroxide revealed that BLD4 provided enhanced protection compared to its isolated components. The BLD4 formulation, resulting from the combination of Dex-Gal and FucA, showed promise as an antioxidant strategy, outperforming its individual components and suggesting its potential as a supplement to mitigate oxidative stress in adverse health conditions.

In-situ gel: A smart carrier for drug delivery

In-situ gel technology is a promising drug delivery strategy that undergoes a 'sol to gel' transition upon administration, providing controlled and prolonged drug release. These gels are composed of cross-linked 3D networks of polymers, with hydrogels being a specific type of absorbing water while retaining their shape. Gelation can be triggered by various stimuli, such as temperature, pH, ions, and light. They offer several advantages like improved patient compliance, extended drug residence time, localized drug delivery, etc, but also have some disadvantages like drug degradation and limited mechanical strength. In-situ gel falls into three categories: temperature-sensitive, ion-sensitive, and pH-sensitive, but multi-responsive gels that respond to multiple stimuli have better drug release characteristics. The mechanism of in-situ gel formation involves physical and chemical mechanisms. There are various applications of in-situ gel, like ocular drug delivery, nose-to-brain delivery, etc. In this review, we have discussed the types, and mechanisms of in-situ gel & use of in-situ gel in the treatment of different diseases through various routes like buccal, vaginal, ocular, nasal, etc., along with its use in targeted drug delivery.