Recent advances in cellulose, pectin, carrageenan and alginate-based oral drug delivery systems.

Polymers-based drug delivery systems constitute one of the highly explored thrust areas in the field of the medicinal and pharmaceutical industries. In the past years, the properties of polymers have been modified in context to their solubility, release kinetics, targeted action site, absorption, and therapeutic efficacy. Despite the availability of diverse synthetic polymers for the bioavailability enhancement of drugs, the use of natural polymers is still highly recommended due to their easy availability, accessibility, and non-toxicity. The aim of the review is to provide the available literature of the last five years on oral drug delivery systems based on four natural polymers i.e., cellulose, pectin, carrageenan, and alginate in a concise and tabulated manner. In this review, most of the information is in tabulated form to provide easy accessibility to the reader. The data related to active pharmaceutical ingredients and supported components in different formulations of the mentioned polymers have been made available.

Design and development of carboxymethylcellulose ester of curcumin as sustained release delivery system in liver.

In the present work chemical transformation of carboxymethylcellulose with curcumin in ester form has led to the development of target specific sustained release delivery system for curcumin in presence of liver esterases. We here report synthesis, characterizations (FTIR, SEM and XRD) curcumin-carboxymethylcellulose ester (Cur-CMC ester) and its target specific hydrolysis to release curcumin. Cur-CMC ester has been found stable when simulated in-vitro in gastric fluid (pH 1.2) and in intestinal fluid (pH 6.8). On in-vitro simulation in liver homogenate curcumin is released from Cur-CMC ester after hydrolysis in a consistent amount (∼43 %) for 5 h. The release of curcumin from ester was highest at pH 8.0 in presence of liver enzymes. The present study suggested that modified CMC support can not only be used for the delivery of curcumin in liver but also acts as prodrug system and released free curcumin in presence of liver esterases.

Alginate hydrogels: Sustained release system to analyze the effect of traditional excipients on curcumin availability.

Curcumin, a molecule of immense pharmacological significance is also known to exhibit poor aqueous solubility and low bioavailability. Different strategies have been adopted to enhance the aqueous solubility of curcumin, but report on the effect of traditional excipients on curcumin solubility still stand in need of. Here, we presented the significance of different traditional excipients used in anti-inflammatory formulations on curcumin solubility. The endeavor has been undertaken with the hypothesis that "traditional formulation used since ages have a scientific basis". To meet the quest we encapsulated 28 different formulations containing varying concentrations of milk, sugar, cow milk fat, and black pepper in alginate hydrogels. After the characterization of formulations through FT-IR, solubility studies were conducted. Milk was found to be an essential component for improved curcumin availability. Individually, cow milk fat and piperine exhibited lesser effect but their synergistic effect was observed in the presence of milk. Dual behavior of sugar has been observed. Traditionally used excipients greatly enhanced the solubility of curcumin. The results have also been validated through anti-oxidant activities of different formulations. Intermolecular interactions have been explained using Molecular modeling studies.

Study on enhanced serum protein protecting and anti-cathepsin activities of various curcumin formulations containing traditional excipients and bio-enhancers.

Cathepsins have emerged out as significant targets in variety of tissue degenerative disorders such as inflammation, alzeimers, tumerogenesis including metastasis and invasion. Elevated levels of cathepsins and reduced cellular inhibitors at the site of these diseased conditions suggest the exploration of novel inhibitors of cathepsins. In the search of effective novel inhibitors as anti-cathepsin agents different natural products are also screened. One such molecule, curcumin has been reported as potential anti-cathepsin agent in recent past. Low solubility of curcumin makes it an important subject for screening effect of different pharmaceutical excipients toward enhanced solubility. In the present work we report serum protein protecting and anti-cathepsin activities of 28 different formulations of curcumin. The formulations have been prepared using four ingredients used in traditional medicinal system. Milk has been found to enhance solubility to a significant level. Cow milk fat, sucrose and piperine exhibited positive cooperation. The results have been explained on the basis of chemical behavior of different ingredients.

Some cetyltrimethylammonium bromide modified polysaccharide supports as sustained release systems for curcumin.

Development of drug delivery systems has emerged out as significant field in medicinal chemistry because of their localized action, low frequency of drug administration and sustained release of drug at the site of action for a prolonged time. Out of various reported methods, in the present work, we report use of five different polysaccharides for the development of sustained release systems for curcumin, utilizing a surfactant, cetyltrimethylammonium bromide (CTAB). Four of these were novel systems and were first optimized. Sustained release of optimized supports was studied by anti-oxidant, serum protein binding and anti-cathepsin activities. Particle size, FT-IR and SEM were used to characterize the modified supports. CTAB-modified-NCCS, -pectin-15 and Alg-5 were found to be the best supports as they released appreciable amount of curcumin for a longer time. The results have also been interpreted using chemical modeling studies.