Patent Application
20230277722
The present disclosure relates to a dressing, more particularly to a dry dressing having a dried hydrocolloid.
Dressings for medical or cosmetic purpose are used to attach to human skin to achieve the skin treating or caring function. Some types of nutrients need to be carried by liquid for better absorption, thus a wet dressing is to soak dressing material in liquid substance and sealed in a bag or container.
Typically, wet dressings contain preservatives to stop germs, but preservatives may cause an allergic reaction to some people's skin. Also, the wet dressing has a certain weight. Moreover, user needs to carefully store the dressing package to prevent pressure from breaking it. Once the container seal is broken and open to air, it is no longer considered sterile and the liquid is tendency to flow out, thereby making the dressing unusable.
The present disclosure provides a dry dressing which is easy to carry and store and has no irritation or allergic reaction to human skin.
According to one aspect of the present disclosure, a dry dressing configured to be applied on human skin. The dry dressing includes a substrate layer and a contact layer that is disposed on the substrate layer. The contact layer includes a hydrocolloid dryly formed on the substrate layer and a nutrient mixed in the hydrocolloid. The hydrocolloid includes polyvinyl alcohol and polyvinylpyrrolidone. A weight percentage of the polyvinyl alcohol and the polyvinylpyrrolidone to the hydrocolloid is not less than 96%, and a weight ratio of the polyvinyl alcohol to the polyvinylpyrrolidone ranges from 0.725 to 0.785
According to the dry dressing discussed above, the hydrocolloid and the nutrient mixed therein dryly formed on the substrate layer helps the dry dressing to be light enough and to be carried and stored easily. Also, additional preservatives is prevented to be added into the dry dressing, and therefore the dry dressing has no irritation or allergic reaction to human skin.
Moreover, by designing the weight ratio of the PVA to the PVP ranging from 0.725 to 0.785, the hydrocolloid is able to fully absorb the water within 3 seconds, and the dry dressing has a proper weight and a proper fixity on human skin for releasing the nutrient.
The present disclosure will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only and thus are not intending to limit the present disclosure and wherein:
Aspects and advantages of the invention will become apparent from the following detailed descriptions with the accompanying drawings. For purposes of explanation, one or more specific embodiments are given to provide a thorough understanding of the invention, and which are described in sufficient detail to enable one skilled in the art to practice the described embodiments. It should be understood that the following descriptions are not intended to limit the embodiments to one specific embodiment. On the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims.
One embodiment of the present disclosure will be illustrated hereinafter with reference to
As shown, the dry dressing 10 includes a substrate layer 100 and a contact layer 200. The contact layer 200 is disposed on the substrate layer 100, and the contact layer 200 includes a hydrocolloid 210 and a nutrient 220. As shown, the hydrocolloid 210 and the nutrient 220 are mixed to each other and distributed in the same layer.
Specifically, the nutrient 220 is in a wet state to mix with the hydrocolloid 210, thus the nutrient 220 is able to be uniformly distributed in the hydrocolloid 210. In some embodiments, the nutrient may be mixed with the hydrocolloid when in a dry state. The contact layer 200 including the hydrocolloid 210 and the nutrient 220 mixed therein, as shown in
The dry dressing 10 is suitable to contact human skin after getting wet. Please further refer to
The hydrocolloid 210 may include polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP), wherein the PVA is provided to enhance the strength of the hydrocolloid 210, and the PVP is provided to enhance the hydrophile of the hydrocolloid 210. In detail, in the hydrocolloid 210, the weight percentage of the PVA and the PVP to the hydrocolloid 210 is 96% or more, and the weight ratio of the PVA to the PVP in the hydrocolloid 210 may range from 0.725 to 0.785. As such, a proper balance between the formability and the hydrophile of the hydrocolloid 210 is obtained. As a result, when the dry dressing 10 gets wet, the hydrocolloid 210 is able to maintain a certain level of fluidity while keeping the nutrient 220 therein.
The following table shows seven formulas suitable for the dry dressing. Among them, the hydrocolloid is about 5 grams, the weigh percentage of the PVA and the PVP to the hydrocolloid is about 96%, and the nutrient contains phycoerythrin to reduce iodine solution. It is noted that the phycoerythrin is provided for user to determine how fast the dry dressing releases the nutrient after getting wet; specifically, the dry dressing can be soaked in iodine solution after gets wet, and then the nutrient 220 will release the phycoerythrin to reduce the iodine solution and thereby decolorize to the iodine solution. By doing so, it is possible to determine the level of releasing the nutrient by observing the transparency of the iodine solution.
As can be seen from the formulas 3-5, the hydrocolloid 210 is able to fully absorb the water within 3 seconds when the weight ratio of the PVA to the PVP ranges from 0.725 to 0.785, thus the dry dressings 10 in formulas 3-5 are suitable to be used with water or essential oil. As can be seen from the formulas 1-2, they need absorb more water to reach the required expansion and their hydrocolloids become fluidly when the weight ratio of the PVA to the PVP is less than 0.725 (i.e., an overly high proportion of the PVP), as a result, the weight of theses dry dressings is quite noticeable by the user and the hydrocolloids are unable to be firmly fixed on the substrate layer, thereby causing user an uncomfortable feeling. As can be seen from the formulas 6-7, they need more time to reach the required expansion and their hydrocolloids tend to become too solid when the weight ratio of the PVA to the PVP is greater than 0.785 (i.e., an overly high proportion of the PVA), as a result, the dry dressings are not easily to be spread and would make user feel uncomfortably warm and wet. Moreover, regarding the formulas 6-7, the weight ratio of the PVA to the PVP greater than 0.785 is not beneficial for the releasing of the nutrient 220 since there is no obvious discoloration of the iodine solution.
It is noted that the hydrocolloid 210 may not only contain PVA and PVP. In some embodiments, the hydrocolloid 210 may include one or more other substances for achieving other effects. For example, the hydrocolloid 210 may further include sodium polyacrylate (PAA-Na). A small amount of PAA-Na can increase the viscosity of the hydrocolloid 210, thus the adding of the PAA-Na to the hydrocolloid 210 may enhance the tactile sensation while using the wetted dry dressing 10. In some embodiments, the weight percentage of the PAA-Na to the hydrocolloid 210 may range from 0.2% to 0.4%.
Optionally, the hydrocolloid 210 may further include xanthan gum and guaran (or called jaguar in some cases) to further increase the strength of the expanded hydrocolloid 210. The xanthan gum and the guaran therefore can prevent the hydrocolloid 210 from being overly supple when the PVA and the PVP in the hydrocolloid 210 encounter specific ions or a substance with an overly low or overly high pH value. The xanthan gum and the guaran can also facilitate the water-absorption of the hydrocolloid 210 and enhance the slippery feeling of the expanded hydrocolloid 210. In detail, the weight percentage of the xanthan gum to the hydrocolloid 210 may range from 0.4% to 0.5%, and the weight percentage of the guaran to the hydrocolloid 210 may range from 0.05% to 0.2%.
The following table shows three formulas of the PAA-Na, the xanthan gum, and the guaran as additions to the dry dressings, and the dry dressings are also evaluated by six evaluators. The result is evaluated sequentially by the tactile quality, the slippery feeling, and the plump feeling. The evaluation results are, from high to low, Formula Y, Formula X, and Formula Z, wherein the evaluation result of Formula Z is too low to be determined as unqualified.
Optionally, the hydrocolloid 210 may further include carboxymethyl cellulose (CMC). In detail, the weight percentage of the CMC to the hydrocolloid 210 may be 0.3% or more. The existence of the carboxymethyl cellulose makes the hydrocolloid 210 possible to be dried within 6 minutes at a relatively low temperature (e.g., below 50° C.). This can prevent deterioration of the nutrient 220 due to high temperature (e.g., more than 50° C.). In some embodiments, the weight percentage of the CMC to the hydrocolloid 210 may range from 0.3% to 2.0% and therefore is beneficial to maintain a high weight percentage of the PVA and the PVP while having a proper drying time of the hydrocolloid 210. Further, designing the weight percentage of the CMC within the range from 0.3% to 2.0% can also save manufacturing cost. The following table shows the relationship between the weight percentage of the CMC to the hydrocolloid 210 and the required drying time of the hydrocolloid 210.
Optionally, the nutrient 220 may include pH-neutral substances, such as hyaluronic acid, fermented β-glucan, and extract of proteoglycan, active ingredients, such as protein and amino acid, antioxidants, such as phycoerythrin, or metal ions, such as calcium ions, magnesium ions, sodium ions, and potassium ions. Among them, the phycoerythrin is able to perform a reduce reaction, as discussed above, to reduce brown iodine molecules into colorless iodine ions. This can know that the phycoerythrin is able to protect skin and eliminate free radicals.
According to the dry dressing discussed above, the hydrocolloid and the nutrient mixed therein dryly formed on the substrate layer helps the dry dressing to be light enough and to be carried and stored easily. Also, additional preservatives is prevented to be added into the dry dressing, and therefore the dry dressing has no irritation or allergic reaction to human skin.
Moreover, by designing the weight ratio of the PVA to the PVP ranging from 0.725 to 0.785, the hydrocolloid is able to fully absorb the water within 3 seconds, and the dry dressing has a proper weight and a proper fixity on human skin for releasing the nutrient.
According to the dry dressing of the present disclosure, the hydrocolloid containing PVA and PVP is suitable for mixing pH-neutral ingredients as the nutrient therein, such as hyaluronic acid, fermented β-glucan, and extract of proteoglycan.
According to the dry dressing of the present disclosure, the hydrocolloid containing xanthan gum and guaran is suitable for mixing metal ions as the nutrient therein, such as calcium ions, magnesium ions, sodium ions, and potassium ions, or active ingredients that are poorly compatible with alcohol, such as protein or amino acid.
The embodiments are chosen and described in order to best explain the principles of the present disclosure and its practical applications, to thereby enable others skilled in the art best utilize the present disclosure and various embodiments with various modifications as are suited to the particular use being contemplated. It is intended that the scope of the present disclosure is defined by the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 111107863 | Mar 2022 | TW | national |
This non-provisional application claims priority under 35 U.S.C. § 119(a) on Patent Application No(s). 111107863 filed in Taiwan, R.O.C. on Mar. 4, 2022, the entire contents of which are hereby incorporated by reference.
