Suppository formulations as a potential treatment for nephropathic cystinosis.

Nephropathic cystinosis is a rare autosomal recessive disease characterised by raised lysosomal levels of cystine in the cells of all the organs. It is treated by the 6-h oral administration of the aminothiol, cysteamine, which has an offensive taste and smell. In an attempt to reduce this frequency and improve the treatment, cysteamine-containing polyethylene glycol suppositories were prepared and evaluated for dissolution and stability. The results demonstrated that cysteamine release was complete after 30 min, and that there was a uniform drug distribution within the formulations. Twelve-month stability tests highlighted a potential incompatibility among some excipients, although stability was demonstrated for the cysteamine suppositories up to 6 months. These suppositories may provide a useful alternative to the current oral therapy for cystinosis.

Gel formulations for treatment of the ophthalmic complications in cystinosis.

Nephropathic cystinosis is a rare autosomal recessive disease characterised by raised lysosomal levels of cystine in the cells of all organs. It is treated by regular administration of the aminothiol, cysteamine. Corneal crystal deposition is one of the most troublesome complications affecting patients and requires the hourly administration of cysteamine eye drops. In an attempt to reduce this frequency and improve the treatment, the preparation and evaluation of cysteamine containing Carbomer gel is reported. The results demonstrated that a weak gel network was formed at low shear-stress, the bioadhesion of the gel was increased with inclusion of a cysteamine derivative (e.g. mean force of 0.067N compared to 0.107N with compound included) and first-order release from the gel was observed. In conclusion these results offer the possibility to formulate cysteamine in an ocular applicable gel formulation.