Comparative study of different approaches for preparation of chlorzoxazone orodispersible tablets

Muscle spasm is a painful involuntary contraction of muscles, which causes involuntary movement and distortion. Chlorzoxazone is a centrally acting muscle-relaxant with sedative properties, but given orally, it is hepatically metabolized leading to decreased bioavailability.

Orodispersible tablets (ODTs) of chlorzoxazone were formulated using two different approaches; by coprocessed excipients (CE) or by liquisolid (LS) technique.

Pharmaburst^® 500, Starlac^®, Pearlitol flash^®, Prosolv^® odt and F-melt^® were used as coprocessed superdisintegrants, whereas in LS, Avicel^® PH101, Microcelac^® 100 and Cellactose^® 80 were used as carriers, while Aerosil^® 200 was the coating material. ODTs were evaluated in terms of weight and thickness variations, drug content, hardness, friability, wetting time, dissolution, disintegration time (DT) and palatability.

In vitro DT of CE-ODTs ranged from 26.43 ± 1.693 s to >180 s, whereas it was between 25.42± 0.203 s to >180 s in LS-ODTs. Complete drug release within 15 min was attained by CE1 prepared with 92.5 mg Pharmaburst^® 500. In vivo DT of CE1 and LS3 were 19.779 ± 0.810 and 18.105 ± 0.423 s, respectively, using six volunteers. Volunteers found that CE1 had more acceptable taste and was more palatable than LS3.

It was concluded that chlorzoxazone ODTs could be successfully formulated using either CE or LS techniques and be used as novel dosage forms for pediatrics and geriatrics showing improved drug release. Moreover, CE technique was superior to LS technique in terms of palatability.