Abstract
Objective: Chitosan (CS)–tripolyphosphate (TPP)–nanoparticles (NPs) have been extensively studied during the past few decades due to their well-recognized applicability in various fields. The present study attempts to optimise the development of these nanoparticles to enhance the percutaneous delivery of caffeine.Methods: CS-TPP-NPs were prepared via ionic cross-linking of CS and TPP and were characterized. The influence of several formulation conditions (CS: TPP mass ratio and concentration of caffeine) and process parameters (stirring speed, stirring time and ultra-sonication time) on the colloidal characteristics of CS-TPP-NPs were investigated and the resulting nanoparticles were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and x-ray diffraction (XRD) analyses. Physicochemical properties, including particle size, zeta potential and polydispersity index (PDI) were examined, and in vitro release studies were conducted to ascertain the release profile of caffeine from the nanoparticles. In addition, the colloidal stability of the prepared NPs was also assessed on storage.Results: Process parameters appeared to exert a significant effect on the physicochemical characteristics of the CS-TPP-NPs. The CS-TPP-NPs prepared under optimum conditions (CS concentration of 0.2 mg/ml, CS: TPP volume ratio of 25:12 ml, stirred at 700 rpm for 60 min, with 0.97 mg/ml caffeine concentration and treatment with low ultra-sonication for 30 min) had shown a mean particle size of ~143.43±1.69 nm, zeta potential of+43.13±1.10 mV, PDI of ~0.30±0.01. A drug loading capacity and encapsulation efficiency of 48.89% and 60.69%, respectively, were obtained. Cumulative release study for drug-loaded CS-NPs was significantly (p<0.001, paired t-test) higher (58.7% caffeine released) compared to control formulation (41.5% caffeine released) after 72 h. Stability studies conducted for 28 d showed that caffeine-loaded CS-NPs degraded much quicker when stored at 25 ⁰C than 4 ⁰C. It was also noted that caffeine-loaded CS-NPs in the freeze-dried form were unstable as the surface charge of nanoparticles dropped from positive zeta potential to-3.55 mV within 2 d at 4 ⁰C and at 25 ⁰C, surface charge dropped to-3.16 mV within 14 d of the experiment.Conclusion: Chitosan (CS)–tripolyphosphate (TPP)–nanoparticles (NPs) appear to be a promising strategy to achieve sustained percutaneous delivery of caffeine.
Highlights
Androgenic alopecia is a common disorder of scalp hair follicles, effecting men and women, resulting in the gradual thinning and increased loss of hair from the scalp
Caffeine is well known as a mild stimulant of the central nervous system where it is transported with blood after its absorption in the stomach and small intestine [5]
The effects of magnetic stirring speed on particle size, polydispersity index (PDI) and zeta potential are summarized in fig. 1 (A, B and C)
Summary
Androgenic alopecia is a common disorder of scalp hair follicles, effecting men and women, resulting in the gradual thinning and increased loss of hair from the scalp. Caffeine has been used as an active compound in anticellulite products because it prevents excessive accumulation of fat in cells [7, 8]. It stimulates the degradation of fats during lipolysis through inhibition of the phosphodiesterase activity [9]. Caffeine act as a phosphodiesterase inhibitor, increasing cAMP levels in cells, counteracting the effects of the DHT hormone and stimulating cell metabolism to promote hair growth [12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
