The use of hydrophobic ion pairing (HIP) of teriparatide resulted in an entrapment efficiency of 77.3 ± 5.7 % (n=3). The positively charged teriparatide was first complexed with sodium dodecyl sulfate (SDS) at a 1:8 molar ratio (1:1 charge ratio). At low pH, all of teriparatide's basic amino acids (8) were assumed to be protonated and forming electrostatic interaction with the negatively charged sulfate group (1) of SDS. The electrostatic interactions result in an overall neutral complex covered by a hydrophobic C12 carbon chain, thereby increasing the hydrophobicity of the peptide and leading to precipitation from aqueous solution. The hydrophobic complex is dispersible and has been observed to be stable in ethanol (Supporting Information Section S4), thus allowing incorporation of the peptide directly into the thin film. Upon rehydration of the thin film the hydrophobic complex would be expected to preferentially locate within the lipid bilayer (hydrophobic environment), resulting in high entrapment efficiency within the liposomes.