Formulation and Evaluation of Bupivacaine-Loaded Glutaraldehyde-Crosslinked High Molecular Weight Chitosan Microspheres

Bk Mandal,M Shivashankar

doi:10.4314/tjpr.v12i1.3

Abstract

Purpose: To develop a chitosan microsphere carrier system of bupivacaine for buccal administration.Methods: Chitosan microspheres loaded with bupivacaine were prepared by emulsification technique based on glutaraldehyde cross-linking and drug-loaded chitosan microsphere were coated with polyglycolic acid (PGA) film The formulated microspheres were characterized by x-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and in vitro release was performed in pH 7.4 phosphate buffer both in the presence and in absence of lysozyme.Results: Encapsulation yield was 83.1 %. SEM studies indicate that the microspheres were spherical and had a relatively smooth surface. XRD and DSC data indicate that there was no interaction between the drug and polymer. In vitro results show that in the presence of lysozyme, 39 % of the drug was released from the microspheres after 4.5 days while maximum drug release (42.5 %) was achieved on day 11. This compares with 31 % drug release on 4.5th day and 38 % on 11th day; maximum drug release occurred on day 11 in the absence of lysozyme.Conclusion: It is evident from this study that microspheres can potentially be used for controlled release of of bupivacaine for the management of dental pain in the buccal cavity.Keywords: Cross-linked chitosan, Microsphere, In vitro release, Oral drug delivery, Bupivacaine, Localanesthesia.

Highlights

Compared to general anesthesia with opioidbased preoperative pain management regional anesthesia can provide benefits of superior pain control, improved patient satisfaction, decreased stress response to surgery reduced operative and post operative blood loss
Liposphere formulation of bupivacaine and lidocaine were previously evaluated as sustained release delivery system for Local anesthesia (LA) [2]
X-ray diffraction (XRD) studies were carried to help to determine the crystallinity of the drug in the cross-linked network (Bucker Germany, CuKά radiation, Nickel filter)

Summary

Introduction

Compared to general anesthesia with opioidbased preoperative pain management regional anesthesia can provide benefits of superior pain control, improved patient satisfaction, decreased stress response to surgery reduced operative and post operative blood loss. Liposphere formulation of bupivacaine and lidocaine were previously evaluated as sustained release delivery system for LA [2] Biostable systems such as hydro gels formed by different polymers and co-polymers have been used to release several drugs [3,4]. Chitosan is mostly hydrophilic and the proportion of acetylated monomers and their distribution in the chains has a critical effect on its solubility and conformation in aqueous media. These characteristics of chitosan have attracted many scientists working in biomedical area and in drug delivery [6,7,8,9]

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