Background: The efficacy of the antiacne topical drugs is well established. The local side effects, however, mainly cutaneous irritation, erythema, dryness, peeling and scaling, remain major problems. Novel vesicular and particulate drug delivery systems have been proposed to reduce the side effects of drugs commonly used in the topical treatment of acne. Objective: This review focuses on the development and evaluation of antiacne drug-loaded vesicular and particulate delivery systems (liposomes, polymeric microspheres and solid lipid nanoparticles) for topical treatment, their advantages and challenges. Methods: All the literature available was reviewed to highlight the potential of these novel systems for the topical treatment of acne. Conclusion: The encapsulation of antiacne drugs in vesicular and particulate delivery systems represents an innovative alternative to minimize side effects, while preserving their efficacy. This can be obtained by the capacity of these systems to provide controlled releas...

Incorporation of anticancer drugs with low lipophilicity in lipid nanocarriers is usually low, which limits the utilization of this strategy in cancer therapy. However, the complexation of these drugs with lipophilic ion pairs containing ionizable groups has been reported to improve their incorporation in nanocarriers such as solid lipid nanoparticles (SLNs), nanostructured lipid nanocarriers (NLCs), and nanoemulsions (NEs). Therefore, those nanocarriers have shown an increase in efficacy and lower toxicity compared with the free drugs, particularly if the counter ion utilized has anticancer activity. Areas covered: This review covers, from 1999 to the present, the utilization of the hydrophobic ion pair (HIP) approach to enhance the encapsulation of anticancer drugs in lipid nanostructured delivery systems, SLN, NLC, and NE; the benefits achieved; and challenges to improve the anticancer therapy. Expert opinion: The HIP strategy has consistently demonstrated enhancement of the encapsulation efficiency in NLCs associated with increased anticancer activity of drugs such as doxorubicin, all-trans retinoic acid, methotrexate, vincristine and others. From this point on, conducting further physicochemical characterization studies of the formed ion pair as well as proceeding with the in vivo efficacy, toxicity and pharmacokinetics studies are expected.

The development of solid lipid nanoparticles (SLN) containing all-trans retinoic acid (RA) is an interesting approach to topical treatment of acne. SLN has potential for controlled release and follicular penetration, which can reduce adverse effects in comparison with conventional formulations. However, the encapsulation efficiency (EE) of RA in SLN is usually low, unless a high surfactant/lipid ratio is used. The aim of this work was to develop SLN with high EE using a low surfactant/lipid ratio. Different formulations of RA-loaded SLN were prepared using glyceryl behenate as lipid matrix. The particle size, EE, zeta potential and differential scanning calorimetry (DSC) were investigated. High EE in SLN was obtained with addition of amines. These results indicate that the utilization of amines is an interesting approach to improve the EE of RA in SLN using a low surfactant/lipid ratio.