Patients worried of getting blind due to glaucoma can now rejoice. Days are not far when thousands of them will have access to an cost-effective medicine to manage their fearsome eye disorder which hitherto make them irreversibly blind with the advancement of the disease, because of either being late in detecting it or of the lack of timely medical care due to the prohibitive cost of medicines.
The Bangalore-based life science major, Sami Labs, has got clearance from the Drugs Controller General of India (DCGI) for conducting the phase III clinical trials of its plant-based eye drop-Forskolin according to the company Chairman and Managing Director, Dr Muhammad Majeed.
‘‘Forskolin—a molecule derived from Coleus forskohlii, a wild plant belonging to the family of Ocimum—is a chemical of alkaloidal type. It drains out the excess water in the eye, thus reducing the pressure from building up in turn reducing glaucoma'', Dr Majeed said. He added that the clinical trials are being carried out at Clinworld, its own subsidiary for clinical trials. The trial will be multi-centric (six centres including Bombay, Delhi and Bangalore), testing the eye drops on hundred patients.
Glaucoma is a condition in which the pressure in the eye is too high, caused by an imbalance between the formation of aqueous humour in the eye and its absorption in, or drainage, out of the eye. Eventually, if the pressure builds up too much, the blood vessels of the optic nerve gets squashed, resulting in irreversible damage to the nerve and reduction in vision or ultimately complete blindness, if left untreated.
There are different types of glaucoma. The two most common ones being acute glaucoma, which is a medical emergency, and chronic simple glaucoma, which develops slowly and often without any symptoms. There are five main types of drugs used in the treatment of glaucoma-miotics, sympathomimetics, beta-blockers, carbonic anhydrase inhibitors, and latanoprost (Xalatan), a drug which copies the effects of the natural chemical prostaglandin.
Most of these drugs are applied directly to the eye in the form of drops, although there are a few drugs that are taken orally.
Forskolin, when applied in drops, addresses the problem caused by increased pressure due to imbalance of water in the eye and re-establishes the balance. There are various side-effects associated with different types of the available synthetic drugs to treat this fearsome eye disease. Miotics can cause severe headache, internal symptoms in the eye including itching, smarting, blurred vision and short sightedness.
Sympathomimetic drugs can cause severe smarting, redness of the eye. Beta-blocker preparation may cause itching, redness, stinging and burning, and dryness of the eye apart from possible systemic (bodily) side-effects. Carbonic anhydrase inhibitors may cause local eye irritation and a bad taste in the mouth. It may even lead to systemic side-effects when administrered with azatozolamide including rashes, nausea, vomiting, darkening, thinning and lengthening of the eye lashes, breathing problems, redness and swelling of the eye etc.
However, the forskolin eye drops are devoid of any such side-effects, claims Dr Majeed. Because of this he expects the drug, once the trials are successful, to conquer the market. Forskolin came into limelight when Hoechst, the German Pharmaceutical company, while screening Indian plants for their medicinal use discovered that it was useful in lowering blood pressure as well as ocular pressure in glaucoma. However, they could not commercialise this product as they were working with a pure compound forskolin as an intravenous injection which was not so effective in controlling blood pressure and could not succeed in obtaining a water soluble form useful as an eye drop.
In the 1990s, Sami Labs and Sabinsa Corporation—its international marketing arm—discovered another property of forskolin. That taken internally, could break down the fat in the body without affecting other tissues. Thus making it a good weight management product too-marketed by the company as Forslean. A US patent was granted for this discovery (Sabinsa Corporation, received the Thomas Alva Edison Patent Award for the year 2004 for this).