Transdermal drug delivery sustained release

Ointments, creams, and plasters are used for transdermal drug delivery. In the latter case, sustained release is accomplished by diffusion from a reservoir through a microporous membrane and into the skin [26,48,49]. Iontophoresis and electroporation has been reported to successfully promote transdermal delivery rates [50-52]. 

Rosin biomaterial has film-forming ability, utilized in the development of film-based drug delivery systems and dosage forms. Sustained release of the drug has been achieved with rosin-coated pellets prepared using diclofenac sodium as a model drug. Therefore, rosins can be used in the development of transdermal drug delivery systems. 

Application of SCF is now the subject of increasing interest especially in the pharmaceutical industry and there are three aims increasing bioavailability of poorly soluble molecules designing sustained-release formulations and formulation of active agents for new types of drug delivery that are less invasive than parental delivery (oral, pulmonary, transdermal). The most complex challenge is related to therapeutic delivery, as it is extremely difficult to obtain a satisfactory therapeutic delivery effect due to biomolecule instability and very short half-life in vivo. 

The applicability and efficiency of the Hn mesophase [43] and the corresponding hexosomes [76] as carriers for a transdermal delivery of desmopressin was also tested. In the case of bulk hexagonal mesophase, reduced values of steady-state flux of the drug and its permeability coefficients through the skin were obtained, and compared to water solution (Fig. 12.24). In other words, the peptide molecules penetrated more easily and freely through the skin from water solution than from hexagonal phase vehicles. Hence, a sustained release of desmopressin was obtained via the Hn mesophase. 

---