Liposomes of terbutaline sulphate: in vitro and in vivo studies.

In vitro studies were conducted to understand the comparative drug diffusion pattern, across artificial membrane, of the drug and of the prepared liposomes of different liposomal membrane composition. In vivo studies were carried out to determine the extent and time-course of pulmonary tissue uptake of administered liposomes containing terbutaline sulphate(TER) on rat lungs. In vitro studies revealed that the drug released from the prepared liposomes obeys Higuchi's diffusion controlled model. Different loading doses and release patterns of drug from the liposomes can be obtained by altering the PC:CHOL ratio and incorporation of cholesterol was found to reduce permeability of the membrane. Similarly drug absorption in vivo in rat's lung following intratracheal instillation, prolonged over 12 hr by liposomal entrapment of TER. The findings of present investigation indicated that liposomally encapsulated TER can be used for pulmonary delivery for maximizing the therapeutic efficacy and reducing undesirable side effects.

Effect of current on dermal permeation of positively charged liposomes.

Transdermal permeation of positively charged liposomally entrapped diphenhydramine hydrochloride (DPH-HCL) has been investigated in presence of pulse D.C. anodic current. Positively charged liposomes were prepared by lipid film hydration technique with stearyl amine as a charge inducer. The prepared liposomes were then subjected to in vitro permeation studies using artificial membrane (cellophane membrane) and human cadaver skin under the influence of iontophoretic current. The effect of variable current density as well as time frequency of application of current onto the release pattern of the plain drug and charged liposomally entrapped drug were studied and the results were compared. The results indicate that application of pulse D.C. anodic current significantly influences the transfer of positively charged liposomally entrapped DPH-HCL across HCS.