History
Precursor drugs to repaglinide were invented in late 1983 by scientists at Dr Karl Thomae GmbH, a German drug manufacturer located at Biberach an der Riß in southern Germany which was acquired by Boehringer Ingelheim in 1990. The drug that became repaglinide was later licensed by Boehringer to Novo Nordisk, which filed an Investigational New Drug application for the compound with the Food and Drug Administration (FDA) in April 1992. Novo Nordisk filed its New Drug Application (NDA) for Prandin in July 1997 and it was quickly approved, gaining FDA approval in December 1997. The drug was the first of the meglitinide class. It was branded Prandin because its quick onset and short duration of action concentrates its effect around meal time (the prandium was the Roman meal which is comparable to the modern lunch). Intellectual property
After several attempts to file for U.S. patent protection, a filing was made in March 1990 which eventually became U.S. Patents 5,216,167 (June 1993), 5,312,924 (May 1994) and 6,143,769 (November 2000). After filing its NDA for repaglinide in 1997, Novo Nordisk applied for patent extension under the Hatch-Waxman Act. This process, called patent term restoration, allows drug patents to be extended based on the time that a drug spent in clinical trials and in the approval process. Previously it had been decided by the U.S. Patent and Trademark Office that the expiration date of U.S. Patents 5,216,167 and 5,312,924 would be 5 September 2006.
The response may result in the destruction of the corneal stroma, resulting in loss of vision due to opacification of the cornea. This is known as immune-mediated stromal keratitis. HSV infection is very common in humans. It has been estimated that one third of the world population have recurrent infection. Keratitis caused by HSV is the most common cause of cornea-derived blindness in developed nations. Therefore, HSV infections are a large and worldwide public health problem. The global incidence (rate of new disease) of herpes keratitis is roughly 1.5 million, including 40,000 new cases of severe monocular visual impairment or blindness each year. Signs and symptoms
Primary infection
Primary infection most commonly manifests as blepharoconjunctivitis i.e. infection of lids and conjunctiva that heals without scarring. Lid vesicles and conjunctivitis are seen in primary infection. Corneal involvement is rarely seen in primary infection. Recurrent eye infection
Recurrent herpes of the eye is caused by reactivation of the virus in a latently infected sensory ganglion, transport of the virus down the nerve axon to sensory nerve endings, and subsequent infection of ocular surface. The following classification of herpes simplex keratitis is important for understanding this disease:

Dendritic ulcer (Epithelial keratitis)
This classic herpetic lesion consists of a linear branching corneal ulcer (dendritic ulcer). During eye exam the defect is examined after staining with fluorescein dye. The underlying cornea has minimal inflammation. Patients with epithelial keratitis complain of foreign-body sensation, light sensitivity, redness and blurred vision. Focal or diffuse reduction in corneal sensation develops following recurrent epithelial keratitis.