Summary by Sneha Subramanian on the paper
Proniosomes used as a drug delivery
Proniosome is basically a dry formulation in which a carrier is coated with a suitable non-ionic surfactant (2000. Hu and Rhodes) and cholesterol (increase the rigidity of niosomal membrane) by dissolving them into an organic solvent. They can be prepared by slurry method using rotary evaporator. In this method a carrier (sucrose, lactose, trehalose and mannitol) is taken in a round bottom flask and a non-ionic surfactant (span 20, 60, 80) with cholesterol and drug (hydrophobic) is dissolved in organic solvent (ethanol or chloroform). Then this solvent is poured into the round bottom flask to make slurry, if the solvent is not enough to make slurry then extra organic solvent can be used to get the desire material. A vacuum and water bath is used in the rotary evaporator to evaporate the organic solvent and allow the solvent phase to make a layer of lipid phase over the carrier. The proniosome can be flushed with nitrogen to remove all the organic solvent. This method can be used to increase the stability of the formulation. Non-ionic surfactant are used instead of phospholipids to get the higher physical and chemical stability (2000. Hu and Rhodes). These substances are biodegradable, biocompatible and have low toxicity (2003. Youan) (2008. Abdelbary) for example sucrose stearate consists of both polar and non-polar group and the combination is due to the ester formation between these two molecules. Sucrose belongs to carbohydrates class and Stearate from fatty acid (palmitic, lauric, stearic acid). So, it acts the same as phospholipid and can entrapped both hydrophilic and lipophilic drugs (2008.Abdelbary).
It is converted into niosomal dispersion by hydration with aqueous solution before administration (2010. Sankar et al), (1998. Vora et al). Niosomes derived from Proniosomes are better (size distribution) than the niosomes prepared from conventional method (2010.Sudhamani.) (2010. Sankar et al). The Proniosomes-based niosomes are more stable both during storage and sterilization. Proniosomes decreases the problems associated with niosomes like fusion, aggregation and leakage of drug (2008.Abdelbary) (2000.Hu and Rhodes). Proniosomes (dry formulation) enhance the transportation, measurement, distribution and storage (2007. Solanki et al) (2010. Sudhamani), (2008. Abdelbary). And this is the property which makes it potentially more suitable for active pharmaceutical Ingredients (2007.Solanki).
One of the advantages is that proniosomes can be converted immediately into niosomes aerosol by hydration in hot water (2001a. Blazek), (2010. Sudhamani), (2007. Solanki.) and form multilamellar niosomes (2000. Hu and Rhodes.). Proniosomes act as a reservoir (carrier) and have been used for the targeted delivery to control the drug release and to achieve a prolong action. As proniosomes-derived niosomes have the ability to encapsulate both hydrophilic (within bilayer) and lipophilic (in central compartmental core) drug (2000.Hu and Rhodes.) so, verity of drug can be delivered to the targeted area (2010.Sudhamani).
The preparation of proniosomes and their evaluation was done by a number of authors (1998. Vora), (2000. Hu and Rhodes), (2001a and 2001 b. Blazek-welsh), (2001. Fang), (2005.Alsara), (2007. Gupta), (2007. Solanki), (2008. Azeem) and (2008. Abdelbary) for their different drug delivery system. Most of them used Proniosomes for the transdermal studies. Proniosomes are potentially very important because of their stability and large scale production. They were highly prepared for the transdermal application due to the non-toxicity and high penetration of non-ionic surfactant through skin (2010.Sankar. last conclusion). However, in future, they will be using for a verity of drug and target areas.