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.

Lipid-Based Nanovesicular Drug Delivery Systems

In designing a new drug, considering the preferred route of administration, various requirements must be fulfilled. Active molecules pharmacokinetics should be reliable with a valuable drug profile as well as well-tolerated. Over the past 20 years, nanotechnologies have provided alternative and complementary solutions to those of an exclusively pharmaceutical chemical nature since scientists and clinicians invested in the optimization of materials and methods capable of regulating effective drug delivery at the nanometer scale. Among the many drug delivery carriers, lipid nano vesicular ones successfully support clinical candidates approaching such problems as insolubility, biodegradation, and difficulty in overcoming the skin and biological barriers such as the blood-brain one. In this review, the authors discussed the structure, the biochemical composition, and the drug delivery applications of lipid nanovesicular carriers, namely, niosomes, proniosomes, ethosomes, transferosomes, pharmacosomes, ufasomes, phytosomes, catanionic vesicles, and extracellular vesicles.

Development and evaluation of pharmacosomes of aceclofenac

Pharmacosomes are amphiphilic lipid vesicular systems containing phospholipid complexes with a potential to improve bioavailability of poorly water soluble as well as poorly lipophilic drugs. To improve the water solubility, bioavailability and minimize the gastrointestinal toxicity of aceclofenac, its pharmacosomes were prepared. Aceclofenac was complexed with phosphatidylcholine (80%) in two different ratios (1:1 and 2:1) using conventional solvent evaporation technique. Pharmacosomes thus prepared were subjected to solubility and drug content evaluation, scanning electron microscopy, differential scanning calorimetry, X ray powder diffraction and in vitro dissolution study. Pharmacosomes of aceclofenac were found to be disc shaped with rough surface in scanning electron microscopy. Drug content was found to be 91.88% (w/w) for aceclofenac phospholipid complex (1:1) and 89.03% (w/w) aceclofenac-phospholipid complex (2:1). Differential scanning calorimetric thermograms and X ray powder diffraction datas confirmed the formation of phospholipid complex. Solubility and dissolution profile of the prepared complex was found to be much better than aceclofenac.