INTRODUCTION

Liposomes are microscopic vesicles with diameters between 20nm and 20um which consist of one or more concentric phospholipid bilayer/s surrounding an aqueous core. They were first described in the 1960s, and because of their structural similarity of cell membranes, they were initially employed as model systems for investigating the flow of materials through membranes. More recently, liposomes have been the subject of extensive study regarding their use for drug delivery.

The importance of liposomes as drug delivery vehicles in now well established. This applies particularly to the ability of liposomes to buffer the toxicity of entrapped drugs while maintaining efficacy. Some areas in which liposomes display therapeutic promise are as carriers of anticancer agents, antifungal drugs, antibacterial, antivirals and antiparasitics. Of these an antifungal Amphotericin B has been in the developed world market for last five years. Others products at advanced stages of development/clinical trial include Cisplatin, Vincristine, Gentamicin, Rifampicin etc.

Amphotericin B is a Polyene Macrolide Antibiotic obtained from Streptomyces sp. which has been in existence for over 3 decades and is known to be one of the most potent Anti-fungal agent. The use of Amphotericin-B, however, has been limited to topical application mainly because of its severe nephrotoxicity, cardiotoxicity, toxicity to central nervous system and to the bone marrow. Inspite of these limitations, injectable formulations are used as last resort. The currently used injectable formulation known as Fungizone is an emulsion of drug in Deoxycholate (a bile salt).

The corporation has come with a new technology using liposome as a carrier and delivery system for Amphotericin-B. The new technology will be highly effective and less toxic as it can carry the drug at the specific site and will require in much lower concentration.

PHARMACOLOGICAL USES:

The drug mainly started on compassionate use basis for AIDS related Systemic Condidiasis and it is under investigation for a number of other fungal infections under various clinical conditions such as:

• Patients of Systemic Candidiasis
• Renal Transplant - Post operative candidiasis.
• Blood Candidiasis in new-borns.
• Children with Nephrotic Syndrome
• Cryptococcal meningitis
• Neuro - aspergillosis.
• Mucor - mycosis
• Leukemia Chemotherapy Children - fungal infection in Immune - suppressed, and even.
• Fluconazole resistant cases of Oral Candidiasis.

TECHNOLOGY STATUS:

The present technology for Liposomal Amphotericine - B have been developed at laboratory/pilot plant scale with an imported equipment which produces about 200 vials per week. Phase-I and Phase-II trials have been completed and necessary protocol for Phase-III trials have been approved.