JAYA GOPAL MEHER, NARAYAN PRASAD YADAV*
*Corresponding author
CSIR-Central Institute of Medicinal and Aromatic Plants, Herbal Medicinal Products Department, Lucknow (U P) 226015, India

Abstract

Emulsion is one of the important classes of delivery system in today’s pharmaceutical market. This has been used as an under-privileged alternative in pharmaceutical sector, nonetheless it enjoys a luminary position in cosmetic and toiletry industry. Being a bi/multiphasic system, it has many advantages as well as drawbacks. Advantages include its ability to accommodate either water soluble and insoluble agents as well as better absorption from the site of administration; on the opposite, stability is the main concern for emulsions. In-depth knowledge of surfactants, additives as well as drug substances helps in the development of comparatively stable and elegant emulsions. Hydrophilic lipophilic balance (HLB) is one of the most imperative but derelict topic in emulsion formulation. Present review is an attempt to bring emulsion in limelight with intense focus on its formulation/development, characterization, HLB and emulsion, current needs and future prospects. In order to put this anthology in a better way, data and literature from various electronic data bases has been collected and presented. It is expected that this review may serve as a way out for the key problems associated with emulsion formulation and development.

INTRODUCTION

Irrespective of advancement in novel drug delivery system as well as expansion of science and technologies, pharmaceutical/cosmetic industry still depends on the conventional delivery system (1, 2). The reasons are very clear that conventional systems are well established in terms of stability, scalability and most importantly cost-effectiveness (3, 4). A majority of pharmaceutical products available in market are solid dosage forms whereas in case of cosmetics/toiletries items, liquid and semisolid products are more popular. Liquid products may be solution, emulsion and suspensions but the semisolid formulations are generally emulsions or gels.
Development of any dosage forms/products depends on many factors including the purpose of application. In cases of pharmaceutical products, solubility, partition coefficient, biological half-life and major adverse effects of active pharmaceutical ingredients are foremost issues of concern. Likewise, in cosmetics apart from these parameters, incorporation of actives, fragrance, colour and essentially consumer compliance are taken into apprehension. As mentioned above stability is the main conc ...