Ramesh Srirangam

Applications of hot-melt extrusion for drug delivery

In todays pharmaceutical arena, it is estimated that more than 40% of new chemical entities produced during drug discovery efforts exhibit poor solubility characteristics. However, over the last decade hot-melt extrusion (HME) has emerged as a powerful processing technology for drug delivery and has opened the door to a host of molecules previously considered unviable as drugs. HME is considered to be an efficient technique in developing solid molecular dispersions and has been demonstrated to provide sustained, modified and targeted drug delivery resulting in improved bioavailability. This article reviews the range of HME applications for pharmaceutical dosage forms, such as tablets, capsules, films and implants for drug delivery through oral, transdermal, transmucosal, transungual, as well as other routes of administration. Interest in HME as a pharmaceutical process continues to grow and the potential of automation and reduction of capital investment and labor costs have made this technique worthy of consideration as a drug delivery solution.

Potential of the bioflavonoids in the prevention/treatment of ocular disorders

Objectives  Flavonoids are a common group of plant polyphenols that give colour and flavour to fruits and vegetables. In recent years, flavonoids have gained importance in the pharmaceutical field through their beneficial effects on human health and are widely available as nutritional supplements. Several pharmacological actions of the bioflavonoids may be useful in the prevention or treatment of ocular diseases responsible for vision loss such as diabetic retinopathy, macular degeneration and cataract. This review aims to summarize the potential therapeutic applications of various bioflavonoids in different ocular diseases and also discusses delivery of these agents to the ocular tissues.

Transcorneal Permeation of l- and d-Aspartate Ester Prodrugs of Acyclovir: Delineation of Passive Diffusion Versus Transporter Involvement

PurposeThe aim of this study was to evaluate the contribution of amino acid transporters in the transcorneal permeation of the aspartate (Asp) ester acyclovir (ACV) prodrug.MethodsPhysicochemical characterization, solubility and stability of acyclovir l-aspartate (l-Asp-ACV) and acyclovir d-aspartate (d-Asp-ACV) were studied. Transcorneal permeability was evaluated across excised rabbit cornea.ResultsSolubility of l-Asp-ACV and d-Asp-ACV were about twofold higher than that of ACV. The prodrugs demonstrated greater stability under acidic conditions. Calculated pKa and logP values for both prodrugs were identical. Transcorneal permeability of l-Asp-ACV

Interaction between Topically and Systemically Coadministered P-Glycoprotein Substrates/Inhibitors: Effect on Vitreal Kinetics

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Evaluation of active and passive transport processes in corneas extracted from preserved rabbit eyes.

was fourfold higher than d-Asp-ACV

Evaluation of the Intravenous and Topical Routes for Ocular Delivery of Hesperidin and Hesperetin

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