Microneedle-Mediated Transdermal Delivery of Tizanidine Hydrochloride.

Tizanidine hydrochloride is a skeletal muscle relaxant used for the treatment of spasm, a sudden involuntary muscle contraction leading to pain. The presently available oral dosage form has limitations such as high first pass metabolism resulting in low oral bioavailability. The short half-life necessitates its frequent administration to maintain the required plasma concentration. Transdermal delivery of drug avoids its first pass hepatic metabolism and gives controlled release, making it possible for reduction in dosing frequency. Drug delivery through transdermal route is severely limited by the presence of a tough stratum corneum barrier. A penetration enhancement approach is often necessary to achieve desired plasma concentrations. Microneedles are very short and sharp needles which do not cause pain. Thus, in the present investigation, preparation and evaluation of a transdermal delivery system for tizanidine hydrochloride based on microneedles are described.

Benign skin lesions: lipomas, epidermal inclusion cysts, muscle and nerve biopsies.

Lipomas are benign skin tumors composed of mature fat cells and are the most common subcutaneous tumors. Although many of these can be removed in the surgical clinic or minor operating room, some require more advanced preoperative planning and more complicated resection. The diagnosis, pathology, and treatment of benign tumors, and other commonly associated tumors that may require a more substantial workup and operative intervention, are discussed. Muscle and nerve biopsies are used for the diagnosis of a variety of medical problems. Although there are other genetic and biochemical markers now available that can diagnose diseases previously proven by biopsy, these surgical techniques still have appropriate uses. Although the procedures are straightforward, there are important technical issues to assist in getting the best specimen to avoid confounding disease diagnosis.