ABSTRACT
In this study, the efficiency of using force control agents [FCAs] namely Polyethylenglycol 6000 [PEG] andpolyvinylpyrrolidone [povidone k-30][PVP] and Sodium lauryl sulfate [SLS] in modifying the surface of lactosewere invisitigated. Lactose surface was modified by sinking within aqueous solution containing one of eachmentioned FCAs. The surface free energies of FCAs unprocessed lactose and processed lactose powders weremeasured using contact angle measurements. Results showed high negative spreading cofficient[lamda[12]] of SLSover lactose which expalins the disability of SLS to adhere to the surfaces of lactose. On other hand, a positive[lamda[12]] value of PVP enabled its adherence to lactose surfaces and so to modify the surface energy to a significantextent. These changes were furthermore observed in case of PEG which had the highest [lamda[12]] compared to others.It is concluded that the more positive the spreading coefficient of a FCA over lactose, the higher the ability of theFCA to modify the surface of lactose is. Also the cohesion works of the powders were directly correlated to theCarr's index and Hausner ratio which are used as indictors of the flow ability. It was also found that all themodified surface lactose powders had surface free energy and cohesion work less than the original lactose.Therefore, surface free energy data can be used as a predict tool to screen for the suitable FCA for each carrier.DSC and FT-IR confirmed the absence of any significant interaction between FCAs and lactose