Mucoadhesive Microspheres: A Promising Tool in Drug Delivery

Abstract

Mucoadhesive polymers have recently gained interest among pharmaceutical scientists as a means of improving drug delivery by promoting the residence time and contact time of the dosage form with the mucous membranes. Mucoadhesion is the process whereby synthetic and natural polymers adhere to mucosal surfaces in the body. If these materials are then incorporated into pharmaceutical formulations, drug absorption by mucosal cells may be enhanced or the drug will be released at the site for an extended period of time. Microspheres, in general, have the potential to be used for targeted and controlled release drug delivery; however, coupling of mucoadhesive properties to microspheres has additional advantages like, a much more intimate contact with the mucus layer, efficient absorption and enhanced bioavailability of the drugs due to a high surface to volume ratio. The present review describes the potential applications of mucoadhesive microspheres as a novel carrier system to improve drug delivery by various routes of administration like buccal, oral, nasal, ocular, vaginal and rectal, either for systemic or for local effects. The mucoadhesive polymers, methods of preparation of microspheres and their in vitro and in vivo evaluation are also described.

Alginate-Based Biomaterials for Regenerative Medicine Applications

“…Delivery systems based on microsphere technologies have been used to deliver cells, growth factors, proteins, genes and other drugs in tissue engineering [68,69,70,71]. Alginates can readily form gel- and solid-microspheres in the presence of suitable methods to be made as delivery systems.…”

“…Biodegradable polymers such as poly(lactic acid) (PLA), poly(lactide-co-glycolide) (PLGA), chitosan, gelatin and alginate are now largely used to prepare microspheres and nanoparticles [2,69,70,71]. Generally, following intravenous injection, nanoparticles can be rapidly cleared from the blood by the mononuclear phagocyte system (MPS).…”

Floating-bioadhesive gastroretentiveCaesalpinia pulcherrima-based beads of amoxicillin trihydrate forHelicobacter pylorieradication

“…The in vitro mucoadhesion of beads was carried out by modifying the method described by Ranga Rao and others (Rao & Buri, 1989;Patil & Murthy, 2006;Patil & Sawant, 2008) using goat gastric mucosa. A freshly cut piece of goat gastric mucosa (2 cm 2 ) was obtained and then cleaned by washing with physiological isotonic saline solution.…”

Recent Progress Toward the Templated Synthesis and Directed Evolution of Sequence-Defined Synthetic Polymers

“…In addition, scientists could introduce building blocks into synthetic polymers with functional groups known to sense specific molecules (McQuade et al, 2000; Spangler et al, 2008; Miller and Chang, 2007), serve as biophysical probes (Spangler et al, 2008), or catalyze specific reactions (White et al, 2001). The ability of synthetic polymers to interact with biological systems can likewise be engineered to confer adhesion to certain tissues (Poncin-Epaillard and Legeay, 2003; Vasir et al, 2003; Woodley, 2001; Patil and Sawant, 2008), biodegradation (Alvarez-Lorenzo and Concheiro, 2008; Shoyele, 2008), or cytotoxicity (Hunter, 2006; Arnon et al, 1989; Galmarini et al, 2008; Kono et al, 2008); conversely, synthetic polymers can be made bio-orthogonal by the appropriate choice of building blocks to limit undesired interference with cellular processes (Yliperttula et al, 2008; Anderson et al, 2008). …”