MUCOADHESIVE POLYMERIC FILMS OF ACYCLOVIR PRONIOSOMES FOR BUCCAL ADMINISTRATION

Objective: The aim of the present work was to formulate and evaluate proniosomes of the poorly soluble drug, acyclovir incorporated in mucoadhesive polymeric films for improved buccal mucosal permeability of the drug while achieving prolonged release. Methods: Acyclovir was formulated as proniosomes using Span 60 and cholesterol. The prepared proniosomes were loaded into mucoadhesive polymeric films prepared with varying quantities of carbopol 934P and HPMC K15M. The proniosome incorporated films were evaluated for physicomechanical characters, mucoadhesion, swelling index, drug content, in vitro drug release and ex vivo permeation through porcine buccal mucosa. Results: Hydration of the proniosomes produced spherical vesicles or niosomes, which was confirmed by Scanning Electron Microscopy. The optimized formulation selected on the basis of vesicle size, entrapment efficiency PDI, Zetz potential and in vitro drug release was selected for incorporation into mucoadhesive polymeric films. All the films showed excellent physicomechanical characters. Formulations with higher proportions of carbopol produced slower in vitro drug release. The kinetics of release of drug from all the formulations appeared to be zero-order based on their regression coefficient values. Comparative evaluation of ex vivo permeation from niosomal and non-niosomal films indicated that the former demonstrated improved mucosal permeation and drug release was also sustained for the 8 h period. Conclusion: Mucoadhesive films impregnated with acyclovir loaded proniosomes could be a potential approach for buccal delivery of acyclovir for improving its absorption and bioavailability.&nbsp

Fast Dissolving Sublingual Films of Ondansetron Hydrochloride: Effect of Additives on in vitro Drug Release and Mucosal Permeation

Ondansetron hydrochloride, a 5 HT3 antagonist is a powerful antiemetic drug which has oral bioavailability of 60% due to hepatic first pass metabolism and has a short half-life of 5 h. To overcome the above draw back, the present study was carried out to formulate and evaluate fast dissolving films of ondansetron hydrochloride for sublingual administration. The films were prepared from polymers such as polyvinylalcohol, polyvinyl pyrrolidone, Carbopol 934P in different ratios by solvent casting method. Propylene glycol or PEG 400 as plasticizers and mannitol or sodium saccharin as sweeteners were also included. The IR spectral studies showed no interaction between drug and polymer or with other additives. Satisfactory results were obtained when subjected to physico-chemical tests such as uniformity of weight, thickness, surface pH, folding endurance, uniformity of drug content, swelling index, bioadhesive strength, and tensile strength. Films were also subjected to in vitro drug release studies by using USP dissolution apparatus. Ex vivo drug permeation studies were carried out using porcine membrane model. In vitro release studies indicated 81–96% release within 7 min and 66–80% within 7 min during ex vivo studies. Drug permeation of 66–77% was observed through porcine mucosa within 40 min. Higher percentage of drug release was observed from films containing the sweeteners. The stability studies conducted for a period of 8 weeks showed no appreciable change in drug content, surface pH, and in vitro drug release

Preparation and Evaluation of Nano-vesicles of Brimonidine Tartrate as an Ocular Drug Delivery System

The objective of the present investigation was to design a vesicular formulation of brimonidine tartrate and evaluate its ability to reduce the dosing frequency and improve the therapeutic efficacy of the drug. Nano-vesicles of brimonidine tartrate were prepared by film hydration method. The prepared vesicles were evaluated for photomicroscopic characteristics, entrapment efficiency, in vitro, and ex-in vitro drug release and in vivo intraocular pressure (IOP) lowering activity. The methods employed for preparation of vesicles produced nano vesicles of acceptable shape and size. The in vitro, and ex-in vitro drug release studies showed that there was slow and prolonged release of the drug, which followed zero-order kinetics. The IOP-lowering activity of nano vesicles was determined and compared with that of pure drug solution and showed that the IOP-lowering action of nano-vesicles sustained for a longer period of time. Stability studies revealed that the vesicle formulations were stable at the temperature range of 2-8°C, with no change in shape and drug content. The results of the study indicate that it is possible to develop a safe and physiologically effective topical formulation that is also convenient for patients

Gecko-inspired chitosan adhesive for tissue repair

The advent of nanotechnology has opened the possibility of fabricating nanoscopic pillars on the surface of polymeric films mimicking the Gecko\u27s foot, in an attempt to increase their adhesive capabilities enhanced by van der Waals forces. However, these forces are considerably weakened in a wet physiological environment. To circumvent this loss in force, current biocompatible adhesives with nanopillars require complex multiple-step fabrication, including an extra layer of adhesive coating to stabilize tissue bonding under physiological conditions. In this report, we describe a simple one-step fabrication process of a single-layer chitosan film that has pillars with base diameter in the range of 100-600 nm and a height of ~70 nm. The nanostructured adhesive is laser-bonded to tissue and does not require pillar coating to enhance bonding in water. In comparison with a \u27flat\u27 adhesive (without pillars), the nanostructured adhesive bonded significantly stronger to tissue under either stress or pressure. Atomic force spectroscopy also confirmed the superior bonding capability of the nanostructured adhesive. This study demonstrates a one-step fabrication technique to produce a monolayer gecko-inspired adhesive that is biocompatible and bonds effectively to tissue