台灣上市之保養品大多僅注重其幼藺吽A常缺乏對於保存期限之穩定性的評估數據。產品的穩定性與有效性及安全性息息相關，因此本研究探討對不同劑型化粧品之穩定性，建立一套可靠的評估系統。
本研究使用不同劑型之市售化粧品做為穩定性探討的樣本，樣本可分為W/O乳化劑型(4個市售品牌)與溶化劑型(8個市售品牌)，其中溶化劑型又可區分為1)水溶性2)油溶性3)膠化性。藉由不同老化變因(溫度、溼度、離心等變因)，測試產品在老化前後的物理及化學特性變化(酸鹼值、色澤、油水分布及黏度)。
各樣品經由穩定性探討後，可得下列結果：1) W/O型乳化化粧品老化前後之變化顯示(a)酸鹼值變化不大(△pH <0.5)；(b)大部分呈現三級以下可感色差(△E <3)；(c)當上下層水分變化大於5%，從外觀可發現到老化後表面有懸浮液體；(d)老化後在低轉速時(0.2sec-1)，黏度呈現降稠現象( 3~5倍)；(e)酸鹼值與色澤間呈現中高度相關(皮爾森相關係數r=0.680)，代表酸鹼值變化較大時，其色澤變化相對也較大。2)溶化劑型化粧品老化前後之變化顯示(a)水溶性及膠化性其酸鹼值變化較小(△pH <0.5)，油溶性呈現偏酸化現象(△pH >1.0)；(b)水溶性及油溶性為四級以上明顯色差(△E >3)，而膠化性為二級以下微小色差(△E <1.5)；(c)溶化劑型之水分變化不大(<2%)；(d)水溶性及油溶性在老化後其黏度無明顯改變，唯膠化性其下層在低轉速時(0.20sec-1)，會有增稠現象(0.3~0.5倍)；(e)水溶性其酸鹼值與水分分布、色澤、黏度彼此間呈現低度相關(r<0.3)；油溶性酸鹼值與水分分布(r=0.857)以及色澤與黏度(r=0.824)呈現高度相關；膠化性色澤與水份分佈呈現高度相關(r=0.864)。
由本研究結果可提供1)乳化與溶化化粧品之穩定性評估檢測參考，2)配方研發與製造流程之修正指標，3)產品保存期限之參考依據 At present, the cosmetics only focus on the efficiency but have no stability evaluation to stand on the shelf life. The stability of cosmetic is relation to efficiency and safety, so the study is discussing the stability with different types of cosmetics to build a system of the stability evaluation.
The study uses different types of cosmetic products to be the sample, include 4 kinds of W/O emulsion and 8 kinds of solubility, this solubility is dividing to 1) water-soluble 2) oil-soluble 3) gel-soluble. After these samples are exposed to different aging factors (ex. temperature、moisture and centrifugation ), measuring the change of physical and chemical characters(ex. pH、color、viscosity and water content ).
After the discussion about the stability of each sample, we can get these results: 1) W/O emulsion cosmetic change form aging shows that (a) The pH has slight change(△pH <0.5);(b)Almost show under level 3 (△E <3) ;(c) When water content change difference between upper and lower layers are more than 5%, we can observe that after aging has liquid suspend in the surface ;(d) Under a shear rate 0.2 sec-1, the viscosity shows decrease phenomenon(about 3~5 folds) ;(e)Between pH with chrominance shows the Pearson Correlation Coefficient ,r=0.680, its mean that when pH changes more bigger and opposites to the chrominance. 2) Solubility cosmetic changes form aging shows that (a) The type of water-soluble and gel-soluble which pH has slight change(△pH <0.5), the oil-soluble product show acidification phenomenon (△pH >1.0) ;(b) The type of water-soluble and oil-soluble which chrominance above level 4 (△E >3), and gel-soluble product has slight change(△E <1.5) ;(c) The water content change of dissolution are slight(<2%);(d) The type of water-soluble and oil-soluble which viscosity have no distinct change, but only the gel-soluble product which lower layer under a shear rate 0.2 sec-1, the viscosity shows increase phenomenon(about 0.3~0.5 folds) ;(e)The water-soluble product which between pH with chrominance、viscosity and water content are both show low relationship(r<0.3); the oil-soluble product which pH with water content(r=0.857) and chrominance with viscosity(r=0.824) show high relationship; the water-soluble product which between chrominance with water content shows high relationship(r=0.864).
In this research, it provides 1) Set up a stability evaluation of the emulsion and solubility cosmetics. 2) Build an indicator to correct the formula and product process. 3) A reference of the shelf life.
