superdisintegrant.

Neuropathic pain is intense in nature and difficult to maintain. The main aim of this study is to provide maximum relief from pain.  The objective was to prepare bilayer tablet comprising  of pregabalin and methylcobalamin for effective treatment of neuropathic pain. Methylcobalamin was formulated as immediate release (IR) layer using super-disintegrant sodium starch glycolate (SSG) whereas pregabalin was formulated as sustained release (SR) layer using polymers hydroxypropyl methyl cellulose (HPMCK4M, K100M)  to deliver the drug at sustained manner effective for the treatment of neuropathic pain. The SR layer of pregabalin is prepared by wet granulation method and IR layer of methylcobalamin is prepared by direct compression method. Tablet blends were evaluated through various pre-compression and post-compression tests. Super disintegrant, SSG at 20% concentration produced excellent results for immediate release of methylcobalamin to exert its action and other additional beneficial effects. The K100M and K4M grade of HPMC produced excellent SR efficiency. Optimum formulation released methylcobalamin and pregabalin at 98.92%  in 45 min and 97.81% in 12 h from respective layers. Pre-compression and post-compression parameters of optimized IR layer comprising Methylcobalamin and SR layer comprising pregabalin exhibit satisfactory results. Bilayer tablet of Methylcobalamin and pregabalin prove to be effective as a combination therapy for the treatment of neuropathic pain by sequential release of the drug.

Over the past few decades, there has been an increased  interest for innovative drug delivery systems to improve safety, efficacy and patient compliance, thereby increasing the product patent life cycle. There are novel types of dosage forms that act very quickly after administration. The basic approach used in development tablets is the use of superdisintegrants like Cross linked carboxymelhyl cellulose (Croscarmeliose), Sodium starch glycolate (Primogel, Explotab), Polyvinylpyrrolidone (Polyplasdone) etc. which provide instantaneous disintegration of tablet after administration. Immediate release liquid dosage forms and parenteral dosage form have also been introduced for treating patients. Liquid dosage form can be suspensions with typical dispersion agents like hydroxypropyl methylcellulose, AOT (dioctylsulfosuccinate) etc. The development of immediate release therapy also provides an opportunity for a line extension in the marketplace, A wide range of drugs (e.g., neuroleptics, cardiovascular drugs, analgesics, antihistamines, and drugs can be considered candidates for this dosage form. In this regard, immediate release formulations are similar to many sustained release formulations that are now commonly available. oral film dosage form not only has certain advantages of other fast disintegrating systems but also satisfies the unmet needs of the market. The present review emphasizes on the potential benefits, design and development of robust, stable, and  innovative orally immediate and their future  scenarios on a global market as a pharmaceutical dosage form.