Recent Advances in the Excipients Used in Modified Release Vaginal Formulations

Abstract

The formulation of an ideal vaginal drug delivery system (DDS), with the requisite properties, with respect to safety, efficacy, patient compliance, aesthetics, harmonization with the regulatory requirements, and cost, requires a meticulous selection of the active ingredients and the excipients used. Novel excipients defined by diversity and multifunctionality are used in order to ameliorate drug delivery attributes. Synthetic and natural polymers are broadly used in pharmaceutical vaginal formulations (solid, semi-solid dosage forms, implantable devices, and nanomedicines) with a promising perspective in improving stability and compatibility issues when administered topically or systemically. Moreover, the use of biopolymers is aiming towards formulating novel bioactive, biocompatible, and biodegradable DDSs with a controllable drug release rate. Overviewing vaginal microenvironment, which is described by variable and perplexed features, a perceptive choice of excipients is essential. This review summarizes the recent advances on the excipients used in modified vaginal drug delivery formulations, in an attempt to aid the formulation scientist in selecting the optimal excipients for the preparation of vaginal products.

Multiple Roles of Chitosan in Mucosal Drug Delivery: An Updated Review

“…Mucoadhesive delivery systems, able to adhere to the vaginal mucosa by chemical and/or physical interactions with the mucus components, were proposed as a successful strategy to overcome the aforementioned drawbacks, by increasing the residence time and assuring a sustained drug release [ 231 ]. Various types of natural or synthetic polymers were used in the development of vaginal drug delivery systems, whose main role is to provide a prolonged residence of the system at the application site and a controlled drug release [ 232 , 233 , 234 ]. Among these polymers, CS appears particularly interesting, due to its favorable biopharmaceutical properties, including good tolerability, biocompatibility, biodegradability, non-toxicity and strong bioadhesive power; this latter is related to its high ability to interact with the negatively charged mucus components, owing to its cationic nature, and to strongly adhere to the mucosa, thus providing a controlled and sustained drug release.…”

“…Among these polymers, CS appears particularly interesting, due to its favorable biopharmaceutical properties, including good tolerability, biocompatibility, biodegradability, non-toxicity and strong bioadhesive power; this latter is related to its high ability to interact with the negatively charged mucus components, owing to its cationic nature, and to strongly adhere to the mucosa, thus providing a controlled and sustained drug release. In addition to these properties, its antimicrobial and anti-inflammatory activities make it an optimal candidate for the development of vaginal drug delivery systems [ 231 , 234 ].…”

A Review on Biomedical Application of Polysaccharide-Based Hydrogels with a Focus on Drug Delivery Systems

“…Moreover, deformable propylene glycol-containing liposomal-based hydrogels are another kind of delivery system arising from hydrogels to fight against vaginal microbial infections via releasing anti-microbial drugs under the control of release rate. Clotrimazole, an anti-fungal drug used in the form of hydrogel to manage vaginitis, can be considered a perfectly matched example in this field to clarify the importance of hydrogels for the vaginal DDS [93]. Regarding this topic, Buckenmeyer et al studied premature ovarian failure via extracellular matrix (ECM) ovarian hydrogels as a follicle carrier, which is schematically represented in Figure 4 [94,95].…”

Development of Dispersible Vaginal Tablets of Tenofovir Loaded Mucoadhesive Chitosan Microparticles for Anti-HIV Pre-Exposure Prophylaxis

“…Vaginal tablets offer advantages over conventional vaginal dosage forms, such as more accurate dosing and greater stability along with low manufacturing cost . They are versatile and can be modulated to obtain sustained or controlled delivery of drugs by incorporating mucoadhesive polymers like sodium alginate, hydroxy propyl methyl cellulose (HPMC), chitosan, and a few more as their primary excipients. − The mucoadhesive polymers are likely to interact with the vaginal surface through specific functional groups in the polymers and biological tissues, enabling the formulation to remain adhered to the vaginal mucosa, while the drug is released. This interaction is crucial to the success of the formulation.…”

“…Chitosan is a nature-derived, hydrophilic, and positively charged mucopolysaccharide, having good biodegradability and biocompatibility. , It has similar flexibility to that of natural tissue and is widely available, making it a sustainable biomaterial for the development of healthcare products and tissue engineering . The ability of chitosan to adhere to mucus is due to its positively charged nature.…”