RESUMO
Postoperative pain management is an important aspect of the overall surgical care process. Effective pain management not only provides patient comfort but also promotes faster recovery and reduces the risk of complications. Bupivacaine (BUP) and Lidocaine (LID) transdermal drug deliveries via thermoplastic polyurethane matrix (TPU) and iontophoresis technique are proposed here as alternative routes for postoperative pain instead of the injection route. Under applied electric field, the amounts of BUP and LID released were 95% and 97% from the loaded amounts, which were higher than the passive patch of 40%. The time to equilibrium of BUP turned out to be faster than the time to equilibrium of LID by approximately 1.5 times. This was due to 2 factors namely the drug molecular weight and the drug pKa value; they play an important role in the selection of a suitable drug for fast-acting or long-acting for the postoperative patients. By using this transdermal patch via iontophoresis system, BUP was deemed as the suitable drug for fast-acting due to the shorter time to equilibrium, whereas LID was the suitable drug for long-acting. The in-vitro drug release - permeation study through a porcine skin indicated the efficiency and potential of the system with the amounts of drug permeated up to 76% for BUP and 81% for LID. The TPU transdermal system was demonstrated here as potential to deliver BUP and LID for postoperative patients.
RESUMO
In this study, silk fibroin (SF) was utilized as the starting material to fabricate physically crosslinked hydrogels. Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) was synthesized and characterized as a drug carrier, with insulin as the model drug. PEDOT:PSS, with a high electrical conductivity of 1666 ± 49 S cm-1, interacted with insulin molecules via electrostatic interaction by replacing the dopant PSS molecules. Insulin-loaded PEDOT:PSS embedded in the SF hydrogel resulted in an increase in the degree of swelling, pore size, and mesh size of the hydrogel. In the in vitro release and release-permeation experiments, the amounts of insulin release and release-permeation were investigated using a modified Franz diffusion cell, under the effects of SF concentrations, electric fields, and pH values. The amounts of insulin release and release-permeation from the pristine SF hydrogel and the PEDOT:PSS/SF hydrogel followed the power laws with the scaling exponents close to 0.5, indicating the Fickian diffusion or the concentration gradient. Under electric fields, with or without PEDOT:PSS used as the drug carrier, the insulin amount and diffusion coefficient were shown to increase with the increasing electric field due to the electro-repulsive forces between the cathode and insulin molecules and SF chains, electroosmosis, and SF matrix swelling. The SF hydrogel and PEDOT:PSS as the drug carrier are demonstrated herein as new components in the transdermal delivery system for the iontophoretically controlled insulin basal release applicable to diabetes patients.
RESUMO
Transdermal insulin delivery is an alternative route to deliver insulin through the body skin with the challenges to overcome the low drug skin permeability and high molecular weight. Polyaniline doped with poly(4-styrenesulfonic acid) (PANI:PSS), a conductive polymer with the high electrical conductivity, was synthesized and utilized as a drug carrier to improve the drug delivery capability from a porous thermoplastic polyurethane (TPU) matrix. The insulin was electrostatically attached to PANI:PSS based on the ion exchange between insulin and PSS. For the in vitro drug release of insulin loaded PANI:PSS relative to the pristine insulin alone, the amount of insulin released was improved to 84.70% with the time to equilibrium of 2 h under the electrical field of 6 V. For the ex vivo release-skin permeation, the amount insulin released and permeated became lower at 57.02% with time to equilibrium of 2 h, due to the pig skin acting as a barrier for insulin permeation. The modified insulin transdermal delivery, with PANI:PSS as the drug carrier and drug enhancer relative to without, is shown here to influence the insulin release rate, amount, and duration, suitable to treat diabetes patients.
Assuntos
Insulina , Polímeros , Humanos , Animais , Suínos , Poliuretanos , Administração Cutânea , Portadores de Fármacos , Condutividade ElétricaRESUMO
Transdermal drug delivery system (TDDS) is the system for transmitting a drug through the skin into the blood circulation. In this work, κ-Carrageenan (κC) was used as the drug matrix material. The porous κC matrices were fabricated by dissolving the κC in deionized water to obtain hydrogels and then using the freeze-dryer to obtain cryogels. The porous (κC) matrices showed interconnected pore sizes varying between 6.05 to 25.8 nm. In the drug release experiments, the drug diffusion coefficient increased and the drug release duration was reduced with decreasing κC concentration due to the larger κC pore sizes. The diffusion coefficient increased with a shorter release time under the applied electric strength of +1.0 V due to the electro-repulsive force between the Metformin and the anode. For the drug release-permeation of the κC 0.8 % v/v cryogel through the pig skin under applied positive electrical potentials, the amounts of drug release-permeation and diffusion coefficients were enhanced with shorter durations relative to without electrical potential. The κC 0.8 % v/v matrix at the applied electric strength of +6.0 V has been shown here to be potential to be used as the Metformin transdermal controlled delivery patch for abdominal obesity and diabetes.
