Caffeine: a potential complexing agent for solubility and dissolution enhancement of celecoxib

Drug complexes: Perspective from Academic Research and Pharmaceutical Market

Despite numerous research efforts, drug delivery through the oral route remains a major challenge to formulation scientists. The oral delivery of drugs poses a significant challenge because more than 40% of new chemical entities are practically insoluble in water. Low aqueous solubility is the main problem encountered during the formulation development of new actives and for generic development. A complexation approach has been widely investigated to address this issue, which subsequently improves the bioavailability of these drugs. This review discusses the various types of complexes such as metal complex (drug-metal ion), organic molecules (drug-caffeine or drug-hydrophilic polymer), inclusion complex (drug-cyclodextrin), and pharmacosomes (drug-phospholipids) that improves the aqueous solubility, dissolution, and permeability of the drug along with the numerous case studies reported in the literature. Besides improving solubility, drug-complexation provides versatile functions like improving stability, reducing the toxicity of drugs, increasing or decreasing the dissolution rate, and enhancing bioavailability and biodistribution. Apart, various methods to predict the stoichiometric ratio of reactants and the stability of the developed complex are discussed.

A Review on Solid Dispersion and Carriers Used Therein for Solubility Enhancement of Poorly Water Soluble Drugs

A large number of hydrophilic and hydrophobic carriers in pharmaceutical excipients are available today which are used for formulation of solid dispersions. Depending on nature of carriers the immediate release solid dispersions and/or controlled release solid dispersions can be formulated. Initially crystalline carriers were used which are transformed into amorphous solid dispersions with enhanced properties. The carriers used previously were mostly synthetic one. Recent trend towards the use of natural carriers have replaced the use of synthetic carriers. This review is the overview of various synthetic, natural, semisynthetic, modified natural hydrophilic carriers used for formulation of solid dispersions.

Directly compressed rosuvastatin calcium tablets that offer hydrotropic and micellar solubilization for improved dissolution rate and extent of drug release

The objective was to use caffeine and Soluplus® to improve the dissolution rate and to maintain a concentration of BCS Class II rosuvastatin calcium that exceeds its solubility. Caffeine and Soluplus® together substantially improved the dissolution rate and the extent of rosuvastatin release. Formulations for direct compression tablets included Formulation F1, a control with drug but with neither caffeine nor Soluplus® present; F2 with drug-caffeine complex; F3 with drug and Soluplus® and F4 with drug-caffeine complex and Soluplus®. Each formulation blend provided satisfactory flow properties. Tablets were comparable in mass, hardness and friability. A marked decrease in disintegration time occurred when the hydrotropic or micellar agent was included in the formulation. Assay (98–100%) and content uniformity (99–100%) results met requirements. Release studies in pH 1.2, 6.6, and 6.8 buffers revealed the superiority of F4. At 45 min sampling time, F3 and F4 tablets each provided a cumulative drug release greater than 70% in each medium. F2 tablets exhibited compliance to official standards in pH 6.6 and 6.8 buffers but not in pH 1.2 buffer, whereas tablets based on F1 failed in each medium. Two-factor ANOVA of the release data revealed a statistical difference across the four formulations in each release medium. Pairwise comparison of release profiles demonstrated that, of the four formulations, F4 provided the most effectively enhanced dissolution rate, improvement to the extent of drug release and support of a concentration higher than the solubility of rosuvastatin calcium.