Preparation and characterization of polylactic acid/phycocyanin-alginate composites for cosmetic patch

Abstract

Patches has recently emerged and attracting more attention for its versatility in many areas such as cosmetic, pharmaceutical and medical. Patches can either be used to administer selected drug to skin or deliver some beneficial ingredients for cosmetic purposes. With that, as polymer is used as the matrix for patches, the polymer selected must be non-toxic, have adhesive property and non-irritative to the skin. Currently, synthetic polymer had been used as the matrix. However, as time passes, people are more concern with the environment, therefore biopolymer is chosen over synthetic polymer as they are degradable and also safe to use. Among all biopolymers, polylactic acid (PLA) was chosen for its many advantages such as having similar properties with conventional plastic and non-toxic. Our invention combines the use of Polylactic Acid (PLA), spirulina extract (phycocyanin) as active ingredient due to its anti-oxidant, anti-inflammatory and bioactive compounds. Alginate was also incorporated into the patch to help improve the properties of the active layer for rapid release of active ingredient. For the first part of this research, a preliminary study was first carried out in order to identify the cytotoxic effect of the raw material, phycocyanin on skin cell. From the result obtained, it was observed that phycocyanin gives no cytotoxic effect to the skin and is deemed safe to be used in the research. The second part of the research was divided into two section, where for the first section fabrication method was selected between two method which were dip cast and roll over method. From the three tests conducted which was tensile test, releasing test and scanning electron microscopy, sample prepared by roll over method gives the best mechanical and releasing properties and was selected for further studies. For the second part, concentration of PLA was varied to study the effect of PLA film prepared with different concentration on the flexibility and releasing properties of sample formed. The concentration of PLA was varied from 7, 10, 13, 15 to 17% (w/v) and PLA film prepared at 13% (w/v) gave the highest elongation at break and moderate releasing properties which were 9.8 % and 0.6 respectively. For the third part of the study, optimization of preparation conditions (stirring time, temperature and concentration of phycocyanin/alginate) were caried by using one factor at a time (OFAT). Two responses were recorded for each parameter which were elongation at break and absorbance (optical density (OD)). FT-IR analysis was also done to further analyse the composites and results obtained showed that phycocyanin and alginate were fully released after releasing test. Other than that, shiftment in band was observed due to formation of phycocyanin and alginate complex when mixed together. From the tests conducted, PLA/phycocyanin-alginate composite prepared at 20 oC for 20 hours with a phycocyanin/alginate ratio of 4:6 at 2.5% (w/v) concentration gave the best properties in terms of flexibility and releasing properties.