Shiwang Sharma, Arvind Sharma
ABSTRACT
Chlorzoxazone (CHZ) is a centrally acting skeletal muscle relaxant. Chlorzoxazone is used to decrease muscle tone and tension to relieve pain and spasm associated with muscoskeletel disorders. CHZ has a half-life of 1- 1.2 hours which is very short and eventually leads to a high dose of 250 to 750 mg 3 to 4 times a day. The aim of the present study is to formulate and characterize a sustained release formulation for the administration of CHZ, to lower its dose and increase bioavailability. Although transdermal administration has shown to deliver the drug to the local sites but major limitation of the transdermal delivery is the slow penetration rate of the drug through skin. Elastic liposomes are an effective tool that can be used to overcome this disadvantage. Elastic liposomes also known as transfersomes are modified lipid carriers that enable drug to reach deeper skin layers and/or the systemic circulation. These vesicular formulations are several orders of magnitudes, more deformable than the standard liposomes and thus well suited for skin penetration. The elastic liposomes were prepared using rotary evaporation sonication method. Particle size and zeta potential were measured by photon correlation spectroscopy. The solid states of the drug in the Elastic liposomes and lipid modification were characterized. Stable chlorzoxazone elastic liposomes having a mean size range of 100 to 200 nm and a zeta potential range of –16 to –21 mV were developed. More than 60% of the chlorzoxazone was entrapped in the EL. The in vitro permeation experiments clearly indicated sustained release of chlorzoxazone with respect to time from elastic liposomal formulations. The prepared elastic liposomes were characterized by differential scanning calorimetry and scanning electron microscopy.