Studies on solubility of curcumin

Curcumin is coming from the Curcuma longa which gives golden color and have the biological importance. As per the survey it is water insoluble, the poor solubility and wettability of curcumin leads to poor dissolution and hence shows poor bioavailability. The present study is aimed at increasing solubility of drug using solid dispersion technique. The solid binary systems were prepared using different drug: polymer ratio (1:1, 1:4 and 1:8) with polyethylene glycol 4000 and 6000 by different techniques like physical mixing, melting method and solvent evaporation method. PVP K 30 was also used as a polymer. The formulations were characterized by scanning electron microscopy, thin layer chromatograpy, compatibility study, diffraction study and in vitro dissolution rate studies. The solubility of drug increased linearly with the increase in polymer concentration. The solid dispersion of drug prepared by hot melt method demonstrated higher drug dissolution rates in comparison to solid dispersion prepared by physical mixtures, solvent evaporation method and pure curcumin. Key-Words: Curcumin, Solid dispersion, Hot melt method, PEG Introduction Oral bioavailability of a drug depends on its solubility and/or dissolution rate, and dissolution may be rate determining step for appearance of medicinal effect, therefore efforts to increase dissolution of drug with limited water solubility is often needed. Many methods are available to improve these characteristics, including salt formation, micronization and addition of solvent or surface active agents. Solid dispersion (SD) is one of these methods, and involved a dispersion of one or more active ingredients in an inner carrier or matrix in solid state prepared by melting, dissolution in solvent or melting solvent method. A huge investigation exposed that turmeric and curcumin has an extensive variety of curative property such as antiinflammatory, antibacterial, antifungal, anticancer antispasmodic , antioxidant , antiamoebic, anti HIV, antidiabetic , antifertility 11 etc. Curcumin, a golden color attained by Curcuma longa is been used from the time immemorial as a nutritional complement, coloring means, spice and also for therapeutic the purpose. It is also accounted that the curcumin is safe and sound up to 8g/day . * Corresponding Author E-Mail: [email protected] Curcuminioids, the oleoresins, resultant by ethanolic extraction of turmeric are mainly liable for golden color and are believed liable for the natural actions. In neutral and acidic situation curcumin shows bis keto form. In acidic condition curcumin performs as an influential hydrogen patron . For improving solubility, dissolution behavior and on set of action solid dispersion is one of the preferable technique. It rivet a spreading of one or more drug component in an inert transporter or matrix in solid state set by melting, dissolution in solvent or melting solvent method. The method has been used for a broad range of weakly water soluble active ingredients such as nimesulide, tenoxicam, nifedipine, nimodipine. The aim of the present work is carried out to develop the water solubility of curcumin by solid dispersions process. Material and methods Curcumin as a drug and other non drug component like PVP, PEG 6000, PEG 4000, and Micro crystalline cellulose were obtained by the Sehat Pvt. Ltd., Gujarat, Himatnagar. All the other regents used were of laboratory grade and used as they acquired. Curcumin solid dispersions Solid dispersions of curcumin were prepared to improve bioavailability by many the following methods among them hot melt method and solvent evaporation methods are common (Table 1). Research Article [Modasiya & Patel, 3(3): Mar., 2012]