Recent Patents on Drug Delivery & Formulation - Volume 8, Issue 2, 2014

Subconjunctival/episcleral, intrascleral, and suprachoroidal routes of drug delivery for treatment of posterior segment eye diseases have become more feasible and popular in the past few years. These routes have the advantage of bypassing the main barriers to topical drug penetration, the ocular surface epithelium, the conjunctivallymphatics, and in the case of deep intrascleral and suprachoroidial delivery, the sclera barrier. Many ocular drug delivery application devices, drug delivery methods, and therapeutics that have been developed for intravitreal use can also be used subconjunctivally, intrasclerally, and in the suprachoroidal space. Alternatively, site-specific devices, such microneedles, and therapeutics, such as hydrogel matrices, have been developed to enhance ocular drug delivery. This manuscript will review the recent research advances and patents on episcleral, intrascleral, and suprachoroidal routes of ocular drug delivery.

Lozenges, the small medicated candies that dissolve slowly in the mouth have always been a favoured delivery system, particularly for drugs meant for relieving sore throats and cold symptoms. This predilection can be attributed mainly to their ability to keep the naso-pharyngeal mucosa moist, enhance the swallowing reflex and provide longer contact time of the drug with the naso-pharyngeal mucosa. A number of innovative technologies have been developed to improve the conventional forms of lozenges i.e. hard candies and compressed tablets. These include the use of novel ingredients/ techniques to enhance taste, reduce calorie content, facilitate quick manufacture and modify the drug release characteristics. Though used extensively for delivery of all kinds of medications for upper respiratory tract disorders, lozenges remain one of the least researched delivery systems. This article reviews various aspects of lozenges as a delivery system. The rationale behind the use of lozenges as the most favoured dosage form for delivery of anti-tussive substances is presented. Delving deeper, various anti-tussive substances that have been delivered as the lozenges including the patents thereof, are also discussed briefly along with the innovative approaches that have been utilised for their formulation improvements.

Microsponge is developing as a novel drug delivery system for controlled release of medicinally active ingredients. It is generally prepared by polymerization or quasi emulsion solvent diffusion technique and has been successfully used for targeted drug delivery. Microsponges are preferred over the microspheres owing to their better drug loading capacity. The present article deals with recent advancements in the microsponge preparation and its pharmaceutical applications and commercial utility considering patents.

In present study, Authors review all aspects of microsphere based novel drug delivery system; including need of natural polymers, different approaches for preparation and recent advancements. Microspheres are a novel drug delivery approach to control release of pharmacologically active ingredient as per patient needs. Natural polymers are cheap, biodegradable and have been proved safe for pharmaceutical formulation. Microspheres of naturally derived polymers have been prepared by several techniques like coacervation phase separation, emulsion polymerization, modified quasiemulsion solvent diffusion, emulsion cross-linking, thermal denaturation, emulsification solvent evaporation, spray drying and suspension polymerisation. It can be concluded from the whole patented study that due to the formation of polymeric network system, enzyme, hormones or other active moiety can be easily entrapped within the matrix. Rate of hydration and swelling of the natural polymer controls the release pattern of the drug from the matrix.

Self-emulsifying compositions are lipidic drug delivery systems that provide a number of delivery advantages. A variety of excipients are available for designing of these drug delivery systems. These systems can be classified as Type I, II, III, and IV, and alternatively as solid, semi-solid, and liquid. Till date many patents have been published on selfemulsifying compositions, and a few commercial products have also been launched. The purpose of this review is to have insights into the patent literature capturing the developments in the area of oral solid self-emulsifying formulations. Though the main emphasis is on developments in solid self-emulsifying formulations, an overview of different manufacturing techniques has also been provided. These formulations can be grouped as conventional, granules, pellets, tablets, supersaturable, controlled release, eutectic-based, and positively charged. The components of self-emulsifying formulations described in this review are not limited only to oils, surfactants, and cosurfactants but also include binders, polymers, diluents, alkalinizing agents, stabilizing agents, preservatives, and viscosity adjusting agents. The inventions highlighted in this article provide useful guidelines for enhancement of oral bioavailability of drugs through this drug delivery platform.

Pharmaceutical scientists involved in drug discovery and drug development are facing serious problems with newer poorly water soluble drugs with respect to their dissolution and bioavailability. Reducing the particle size of active pharmaceutical ingredient has been an efficient and reliable method for improving the bioavailability of insoluble drugs. Nanosuspension has emerged as an efficient and promising strategy for delivery of insoluble drugs due to its unique advantages such as ease of modification, process flexibility, targeting capabilities, altered pharmacokinetic profile leading to safety and efficacy. These unique features of nanosuspension have enabled its use in various dosage forms, including specialized delivery systems such as oral, parenteral, peroral, ocular and pulmonary routes. Currently, efforts are being directed to extend their applications in site-specific drug delivery. Large numbers of products based on nanosuspension are in the market and few are under clinical trials. The commercialization potential of nanosuspension based formulation for oral route is well established and products for other routes will enter the market within short span. Among the various techniques available, only wet milling technique has been successfully used for commercial production of nanosuspension. Nanosuspension based patents have extensive potential of reaching faster in the market as compared to other nanotechnology based formulations. This review covers various aspects of techniques of preparation, route of administration and commercialization of nanosuspension with main focus on the recent patents granted in the field.

Insulin was discovered over 90 years ago. However oral insulin still remains a challenging and elusive goal. Extensive efforts are being made worldwide for developing noninvasive drug delivery systems, mainly via oral route as it is the most widely accepted means of administration. The main barriers faced in oral protein delivery are the enzymatic degradation and poor permeability across the intestinal wall. The approaches for developing an oral insulin delivery system mainly focus on overcoming these barriers. To overcome the gastro-intestinal barriers various types of formulations such as insulin conjugates, permeation enhancers, micro/nanoparticles, liposomes etc. are investigated. In the recent years a number of advances have taken place in understanding the needs and workable mechanisms of improved oral peptide delivery systems. In this review the recent patents on oral insulin is focused. Emphasis is on the technologies based on permeation enhancers and nanoparticle based carrier systems.