The development of an oral single dose emulgel formulation for Pheroid® technology

Abstract

Dosage forms have been developed over the years for various applications. The dosage form consists of the active drug in combination with pharmaceutical excipients. The pharmaceutical excipients solubilise, suspend, thicken, dilute, emulsify, stabilise, preserve, colour and flavour medicinal agents into efficacious and appealing dosage forms. The dosage form under investigation in this study is of the oral type. The Pheroid® is a unique drug delivery system which consists of an oil-in-water emulsion system. Emulsion based drug systems provide a suitable medium for the delivery of both hydrophobic and hydrophilic drugs which can be incorporated into its oil or water phase for delivery to the site of action. These advantages make them more efficient as dosage form. Emulgels are either emulsion of oil-in-water or water-in-oil type, which is gelled by mixing with gelling agents. Incorporation of emulsion into gel increases its stability and makes it a dual control release system. The presence of the gel phase makes it a non-greasy formulation which favours good patient compliance. A strategy followed to improve the stability of the emulgel system is the packaging of the formula into single dose sachets to protect the product against physical and chemical breakdown during patient usage. All factors such as selection of gelling agent, preservatives and formulation methods influencing the stability and efficacy of Pheroid® emulgel are discussed. In this study, three different emulsifiers were added to the formula and the analysis of visual appearance, pH measurements, rheological studies, light microscopy and confocol laser scanning microscopy (CLSM) will provide an insight to the potential usage of emulgel as drug delivery system. A range of para-hydroxybenzoate esters was tested in the Pheroid® emulgel and the most suitable candidate chosen for further accelerated stability testing. It was thus possible to prepare a single dose emulgel with Carbopol® 934P (0.2% w/v) as an emulsifier, with Nipastat® (0.175% w/v) and PG (10% v/v) as preservatives into a stable dosage form suitable for further product development.