ABSTRACT

One important element in the formulation design of a successful oil based system is the ability of the lipid composite to retain its solvent capacity after dilution in the physiological media. There is a trend of moving towards extremely hydrophilic systems in order to improve the bioavailability of lipophilic compounds. This, however, raises concerns regarding the loss of solvent capacity after dispersion, hence inducing drug crystallization. In this investigation, self-microemulsifying systems composed of either hydrophilic or water insoluble components were developed. Various hydrophilic polymers were also screened for masking the salting out effect of electrolytes present in the emulsification media. Two lipid mixtures containing (a) Miglyol 812/Imwitor 988/ Cremophor EL (hydrophilic) or (b) Captex 300/Caprol PGE 860/Acconon CC-6 (lipophilic) were optimized for self-microemulsification; droplet size was measured using PCS. Lipid mixtures were emulsified in electrolyte solution (SGF) containing various polymers including; PVP, PEG 6000, Lutrol F68 or Lutrol F127. Phase diagrams showed selfmicroemulsifying mixtures with optimal blends of Miglyol 812/Imwitor at ratios of 5:5 using 30% w/w Cremophor EL, or Captex 300/Caprol PGE-860 at ratios 3:7 with Accnon CC 60% w/w. Electrolytes present in the media only affected the emulsification of the system with the water insoluble excipients. This effect was inhibited by including Lutrol F127. A potential self-microemulsifying system was developed using water insoluble materials. Solvent capacity of this system is unlikely to be compromised hence avoiding drug precipitation. Lutrol F127 was found to counteract the effect of electrolytes in the media. Keywords: SMEDDS, SEDDS, Poloxamer 407, Oil formulations and Poorly water-soluble drugs
Publication date: 01/04/21

https://ijbpas.com/pdf/2021/April/MS_IJBPAS_2021_5420.pdf

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https://doi.org/10.31032/IJBPAS/2021/10.4.5420