Specific Gravity Of Simple Syrup And Sugar Concentration At 150C

2[Pb (CH 3 COO) 2 . Pb(OH) 2 ] +CO 2 → PbCO 3 . Pb(OH) 2 + 2Pb(CH 3 COO) 2 + H 2 O

To avoid the water absorbing a large amount of CO2 from the air, at the beginning of heating, people only dissolve lead acetate in a certain amount of water needed to obtain lead acetate base. The remaining water will be added after the reaction is finished. It is important to note that it should not be heated for too long because the lead acetate will decompose into acetic acid and easily become carbonated.

Lead acetate base solution is a clear, colorless solution, slightly sweet and astringent taste, with a slightly alkaline reaction. Easily carbonated in air. Store the solution in a tightly closed bottle.

The lead acetate base solution must contain 13.5 – 14.8% lead. From this solution, people mix lead acetate base water: Lead acetate base solution 2g

Normal water approx 100ml

Mix well to obtain a milky white liquid due to the insoluble lead carbonate, sulfate, and chloride that are formed. Lead acetate base water contains 0.28% lead, used to apply to bruises.

In case the drug solution contains substances that reduce the solubility of the drug

As mentioned in the general technical section, poorly soluble salts with the drug, electrolytes, and ions with the same name reduce the solubility of the drug in solution. It is necessary to dilute the concentration of these substances to avoid precipitation of the drug when dissolved.

Example: Rp. Codeine phosphate 0.5g

Sodium bromide 10g

Water 200ml

Mf Sol

In a solution containing bromide ions, soluble codeine phosphate (solubility 1:3.5) converts to slightly soluble codeine hydrobromide (solubility 1:100) which needs to be dissolved separately, diluted and then combined with the two drug solutions.

4.1.3. Packaging and testing of finished products

Specific regulations for each liquid medicine preparation.

4.2. Syrup

4.2.1. Definition, classification

Define

Syrup is an oral solution containing high concentrations of white sugar (sucrose) or other sugars in purified water, containing medicinal substances or extracts from medicinal herbs.

Simple syrup is a nearly saturated solution of white sugar in pure water.

Syrups have some advantages such as: Can mask the unpleasant taste of some drugs, suitable for children, with high sugar content can limit the growth of mold bacteria.

Classify

According to the way of dissolving sugar, syrup is divided into two types: Hot prepared syrup and cold prepared syrup.

According to the purpose of use, syrup is divided into carrier and medicinal syrup. Medicinal syrup contains medicinal substances that have the effect of treating diseases. Syrup used as a carrier does not contain medicinal substances.

Substances, only aromatics, flavorings (such as simple syrup, orange peel syrup, white ant syrup) used to mix with pharmaceutical ingredients when preparing medicine.

4.2.2. Ingredients

The main ingredients of syrup include pharmaceutical substances, solvents and sugar. Syrup can contain one or more types of sugar such as sucrose, glucose, fructose, sorbitol, mannitol, saccharin.

- Substances that increase solubility, bioavailability and stability of syrup such as: glycerin, propylene glycol, ethanol.

- Viscosity increasing agents such as NaCMC, PEG 1500…

- Substances that create pH buffers and adjust pH to ensure stability for pharmaceuticals such as citric acid, tartaric acid, HCl, NaOH...

- Antioxidants such as Na2EDTA , sodium metabisulfite…

- Anti-mold preservatives: nipagin, nipasol.

- Colorants, flavorings…

4.2.3. Preparation techniques

Prepare medicinal syrup by dissolving the drug, combining the drug solution into a simple syrup.

This preparation method is often applied to cases where the medicinal syrup has active ingredients that are easily soluble in the single syrup, the toxic active ingredients need to be dissolved in a suitable solvent and then combined with the single syrup, ensuring the correct content of active ingredients. The stages are as follows:

Preparation of simple syrup:

Simple syrup is prepared by dissolving sucrose in hot water or dissolving at room temperature.

Simple syrup recipe when prepared by hot dissolving: Sucrose 165 g

Distilled water 100 ml

Sucrose is dissolved in water and placed on a water bath, the temperature should not exceed 60 o C. Filter the hot syrup through several layers of gauze. Check the specific gravity of the syrup at 105 o C is 1.26 (or at 20 0 C is 1.314) corresponding to a concentration of 64% sugar in the syrup.

Simple syrup recipe prepared at room temperature: Sucrose 180 g

Distilled water 100 ml

.Sucrose is placed in a cloth bag immersed in the water surface, left alone, the dissolution process occurs naturally by convection from top to bottom. When the sugar is completely dissolved, stir well, and syrup with the given sugar concentration is obtained according to the formula (because there is no solvent evaporation as when dissolving hot). A decanter-type device can be used to prepare simple syrup at room temperature.

Simple syrups of sugars are prepared similarly to the above with sugar content depending on the formula (such as 70% sorbitol syrup, 60% glucose...).

Prepare pharmaceutical solution (if any):

If the syrup contains toxic drugs in table A or table B, it is necessary to use a minimum amount of suitable solvent to dissolve and form a drug solution. Toxic drugs often have small content, a small amount of toxic drug solution has a negligible effect on the sugar concentration in the syrup, but it is necessary to ensure that the drugs are completely dissolved and mixed evenly in the syrup.

Some herbal extracts are concentrated for convenience when mixed with simple syrup. Usually the ratio of concentrated extract to simple syrup is 1:10.

Dissolve the drug, combine the drug solution and simple syrup:

Single syrup has high viscosity and needs to be heated to easily dissolve the active ingredients. Dissolving active ingredients into single syrup has the advantage of not reducing the ratio of sugar and water in the syrup.

Drug solutions prepared with water or water-based solvents (such as ethanol, glycerin, propylene glycol...) can be easily mixed evenly with simple syrups.

Other excipients in the composition are dissolved into the drug solution or simple syrup in a reasonable manner depending on the role of the excipients and the properties of the drug.

Complete preparation:

The syrup is filtered (hot filtered), tested and must meet the set standards before being packaged as a finished product.

Prepare syrup by dissolving sugar in pharmaceutical solution.

This preparation method is often applied to prepare most medicinal syrups because it is convenient for mixing pharmaceutical solutions, as well as dissolving additives and different types of sugars in the formula.

The stages are as follows:

Prepare pharmaceutical solution:

Pharmaceutical solutions can be prepared by conventional or special dissolution methods. Extracts are prepared by extracting medicinal herbs, or dissolving from medicinal extracts. The solvent is aromatic water prepared by distillation, some other additives are dissolved at this stage to stabilize the pharmaceutical solution or increase the solubility of the pharmaceutical substance.

Dissolve sugar in pharmaceutical solution:

Sugar may be dissolved hot or at room temperature into the drug solution, as described in the preparation of simple syrups.

The hot dissolution method has the advantage of being fast and easy to filter the syrup, but it cannot be applied when the drug is easily decomposed by heat. Hot prepared syrups are often darker in color due to caramelization and contain reducing sugars due to sucose hydrolysis.

Bring sugar concentration to the specified limit:

The concentration of sugar in syrup can be determined by measuring the density or measuring the boiling point, so there is a correlation between concentration and density, concentration and boiling point.

Table 3.3. Specific gravity of simple syrup and sugar concentration at 15 0 C

Sugar concentration (%)

Syrup density
65	1,3207
64	1,3146
60	1,2906
55	1,2614

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• Qos Assurance Methods for Multimedia Communications zt2i3t4l5ee zt2a3gs zt2a3ge zc2o3n4t5e6n7ts low. The EF PHB requires a sufficiently large number of output ports to provide low delay, low loss, and low jitter. EF PHBs can be implemented if the output port's bandwidth is sufficiently large, combined with small buffer sizes and other network resources dedicated to EF packets, to allow the router's service rate for EF packets on an output port to exceed the arrival rate λ of packets at that port. This means that packets with PHB EF are considered with a pre-allocated amount of output bandwidth and a priority that ensures minimum loss, minimum delay and minimum jitter before being put into operation. PHB EF is suitable for channel simulation, leased line simulation, and real-time services such as voice, video without compromising on high loss, delay and jitter values. Figure 2.10 Example of EF installation Figure 2.10 shows an example of an EF PHB implementation. This is a simple priority queue scheduling technique. At the edges of the DS domain, EF packet traffic is prioritized according to the values ​​agreed upon by the SLA. The EF queue in the figure needs to output packets at a rate higher than the packet arrival rate λ. To provide an EF PHB over an end-to-end DS domain, bandwidth at the output ports of the core routers needs to be allocated in advance to ensure the requirement μ > λ. This can be done by a pre-configured provisioning process. In the figure, EF packets are placed in the priority queue (the upper queue). With such a length, the queue can operate with μ > λ. Since EF was primarily used for real-time services such as voice and video, and since real-time services use UDP instead of TCP, RED is generally not suitable for EF queues because applications using UDP will not respond to random packet drop and RED will strip unnecessary packets. 2.2.4.2 Assured Forwarding (AF) PHB PHB AF is defined by RFC 2597. The purpose of PHB AF is to deliver packets reliably and therefore delay and jitter are considered less important than packet loss. PHB AF is suitable for non-real-time services such as applications using TCP. PHB AF first defines four classes: AF1, AF2, AF3, AF4. For each of these AF classes, packets are then classified into three subclasses with three distinct priority levels. Table 2.8 shows the four AF classes and 12 AF subclasses and the DSCP values ​​for the 12 AF subclasses defined by RFC 2597. RFC 2597 also allows for more than three separate priority levels to be added for internal use. However, these separate priority levels will only have internal significance. PHB Class PHB Subclass Package type DSCP AF4 AF41 Short 100010 AF42 Medium 100100 AF43 High 100110 AF3 AF31 Short 011010 AF32 Medium 011100 AF33 High 011110 AF2 AF21 Short 010010 AF22 Medium 010100 AF23 High 010110 AF1 AF11 Short 001010 AF12 Medium 001100 AF13 High 001110 Table 2.8 AF DSCPs The AF PHB ensures that packets are forwarded with a high probability of delivery to the destination within the bounds of the rate agreed upon in an SLA. If AF traffic at an ingress port exceeds the pre-priority rate, which is considered non-compliant or “out of profile”, the excess packets will not be delivered to the destination with the same probability as the packets belonging to the defined traffic or “in profile” packets. When there is network congestion, the out of profile packets are dropped before the in profile packets are dropped. When service levels are defined using AF classes, different quantity and quality between AF classes can be realized by allocating different amounts of bandwidth and buffer space to the four AF classes. Unlike EF, most AF traffic is non-real-time traffic using TCP, and the RED queue management strategy is an AQM (Adaptive Queue Management) strategy suitable for use in AF PHBs. The four AF PHB layers can be implemented as four separate queues. The output port bandwidth is divided into four AF queues. For each AF queue, packets are marked with three “colors” corresponding to three separate priority levels. In addition to the 32 DSCP 1 groups defined in Table 2.8, 21 DSCPs have been standardized as follows: one for PHB EF, 12 for PHB AF, and 8 for CSCP. There are 11 DSCP 1 groups still available for other standards. 2.2.5.Example of Differentiated Services We will look at an example of the Differentiated Service model and mechanism of operation. The architecture of Differentiated Service consists of two basic sets of functions: Edge functions: include packet classification and traffic conditioning. At the inbound edge of the network, incoming packets are marked. In particular, the DS field in the packet header is set to a certain value. For example, in Figure 2.12, packets sent from H1 to H3 are marked at R1, while packets from H2 to H4 are marked at R2. The labels on the received packets identify the service class to which they belong. Different traffic classes receive different services in the core network. The RFC definition uses the term behavior aggregate rather than the term traffic class. After being marked, a packet can be forwarded immediately into the network, delayed for a period of time before being forwarded, or dropped. We will see that there are many factors that affect how a packet is marked, and whether it is forwarded immediately, delayed, or dropped. Figure 2.12 DiffServ Example Core functionality: When a DS-marked packet arrives at a Diffservcapable router, the packet is forwarded to the next router based on Per-hop behavior is associated with packet classes. Per-hop behavior affects router buffers and the bandwidth shared between competing classes. An important principle of the Differentiated Service architecture is that a router's per-hop behavior is based only on the packet's marking or the class to which it belongs. Therefore, if packets sent from H1 to H3 as shown in the figure receive the same marking as packets from H2 to H4, then the network routers treat the packets exactly the same, regardless of whether the packet originated from H1 or H2. For example, R3 does not distinguish between packets from h1 and H2 when forwarding packets to R4. Therefore, the Differentiated Service architecture avoids the need to maintain router state about separate source-destination pairs, which is important for network scalability. Chapter Conclusion Chapter 2 has presented and clarified two main models of deploying and installing quality of service in IP networks. While the traditional best-effort model has many disadvantages, later models such as IntServ and DiffServ have partly solved the problems that best-effort could not solve. IntServ follows the direction of ensuring quality of service for each separate flow, it is built similar to the circuit switching model with the use of the RSVP resource reservation protocol. IntSer is suitable for services that require fixed bandwidth that is not shared such as VoIP services, multicast TV services. However, IntSer has disadvantages such as using a lot of network resources, low scalability and lack of flexibility. DiffServ was born with the idea of ​​solving the disadvantages of the IntServ model. DiffServ follows the direction of ensuring quality based on the principle of hop-by-hop behavior based on the priority of marked packets. The policy for different types of traffic is decided by the administrator and can be changed according to reality, so it is very flexible. DiffServ makes better use of network resources, avoiding idle bandwidth and processing capacity on routers. In addition, the DifServ model can be deployed on many independent domains, so the ability to expand the network becomes easy. Chapter 3: METHODS TO ENSURE QoS FOR MULTIMEDIA COMMUNICATIONS In packet-switched networks, different packet flows often have to share the transmission medium all the way to the destination station. To ensure the fair and efficient allocation of bandwidth to flows, appropriate serving mechanisms are required at network nodes, especially at gateways or routers, where many different data flows often pass through. The scheduler is responsible for serving packets of the selected flow and deciding which packet will be served next. Here, a flow is understood as a set of packets belonging to the same priority class, or originating from the same source, or having the same source and destination addresses, etc. In normal state when there is no congestion, packets will be sent as soon as they are delivered. In case of congestion, if QoS assurance methods are not applied, prolonged congestion can cause packet drops, affecting service quality. In some cases, congestion is prolonged and widespread in the network, which can easily lead to the network being "frozen", or many packets being dropped, seriously affecting service quality. Therefore, in this chapter, in sections 3.2 and 3.3, we introduce some typical network traffic load monitoring techniques to predict and prevent congestion before it occurs through the measure of dropping (removing) packets early when there are signs of impending congestion. 3.1. DropTail method DropTail is a simple, traditional queue management method based on FIFO mechanism. All incoming packets are placed in the queue, when the queue is full, the later packets are dropped. Due to its simplicity and ease of implementation, DropTail has been used for many years on Internet router systems. However, this algorithm has the following disadvantages: − Cannot avoid the phenomenon of “Lock out”: Occurs when 1 or several traffic streams monopolize the queue, making packets of other connections unable to pass through the router. This phenomenon greatly affects reliable transmission protocols such as TCP. According to the anti-congestion algorithm, when locked out, the TCP connection stream will reduce the window size and reduce the packet transmission speed exponentially. − Can cause Global Synchronization: This is the result of a severe “Lock out” phenomenon. Some neighboring routers have their queues monopolized by a number of connections, causing a series of other TCP connections to be unable to pass through and simultaneously reducing the transmission speed. After those monopolized connections are temporarily suspended, Once the queue is cleared, it takes a considerable amount of time for TCP connections to return to their original speed. − Full Queue phenomenon: Data transmitted on the Internet often has an explosion, packets arriving at the router are often in clusters rather than in turn. Therefore, the operating mechanism of DropTail makes the queue easily full for a long period of time, leading to the average delay time of large packets. To avoid this phenomenon, with DropTail, the only way is to increase the router's buffer, this method is very expensive and ineffective. − No QoS guarantee: With the DropTail mechanism, there is no way to prioritize important packets to be transmitted through the router earlier when all are in the queue. Meanwhile, with multimedia communication, ensuring connection and stable speed is extremely important and the DropTail algorithm cannot satisfy. The problem of choosing the buffer size of the routers in the network is to “absorb” short bursts of traffic without causing too much queuing delay. This is necessary in bursty data transmission. The queue size determines the size of the packet bursts (traffic spikes) that we want to be able to transmit without being dropped at the routers. In IP-based application networks, packet dropping is an important mechanism for indirectly reporting congestion to end stations. A solution that prevents router queues from filling up while reducing the packet drop rate is called dynamic queue management. 3.2. Random elimination method – RED 3.2.1 Overview RED (Random Early Detection of congestion; Random Early Drop) is one of the first AQM algorithms proposed in 1993 by Sally Floyd and Van Jacobson, two scientists at the Lawrence Berkeley Laboratory of the University of California, USA. Due to its outstanding advantages compared to previous queue management algorithms, RED has been widely installed and deployed on the Internet. The most fundamental point of their work is that the most effective place to detect congestion and react to it is at the gateway or router. Source entities (senders) can also do this by estimating end-to-end delay, throughput variability, or the rate of packet retransmissions due to drop. However, the sender and receiver view of a particular connection cannot tell which gateways on the network are congested, and cannot distinguish between propagation delay and queuing delay. Only the gateway has a true view of the state of the queue, the link share of the connections passing through it at any given time, and the quality of service requirements of the traffic flows. The RED gateway monitors the average queue length, which detects early signs of impending congestion (average queue length exceeding a predetermined threshold) and reacts appropriately in one of two ways: − Drop incoming packets with a certain probability, to indirectly inform the source of congestion, the source needs to reduce the transmission rate to keep the queue from filling up, maintaining the ability to absorb incoming traffic spikes. − Mark “congestion” with a certain probability in the ECN field in the header of TCP packets to notify the source (the receiving entity will copy this bit into the acknowledgement packet). Figure 3. 1 RED algorithm The main goal of RED is to avoid congestion by keeping the average queue size within a sufficiently small and stable region, which also means keeping the queuing delay sufficiently small and stable. Achieving this goal also helps: avoid global synchronization, not resist bursty traffic flows (i.e. flows with low average throughput but high volatility), and maintain an upper bound on the average queue size even in the absence of cooperation from transport layer protocols. To achieve the above goals, RED gateways must do the following: − The first is to detect congestion early and react appropriately to keep the average queue size small enough to keep the network operating in the low latency, high throughput region, while still allowing the queue size to fluctuate within a certain range to absorb short-term fluctuations. As discussed above, the gateway is the most appropriate place to detect congestion and is also the most appropriate place to decide which specific connection to report congestion to. − The second thing is to notify the source of congestion. This is done by marking and notifying the source to reduce traffic. Normally the RED gateway will randomly drop packets. However, if congestion If congestion is detected before the queue is full, it should be combined with packet marking to signal congestion. The RED gateway has two options: drop or mark; where marking is done by marking the ECN field of the packet with a certain probability, to signal the source to reduce the traffic entering the network. − An important goal that RED gateways need to achieve is to avoid global synchronization and not to resist traffic flows that have a sudden characteristic. Global synchronization occurs when all connections simultaneously reduce their transmission window size, leading to a severe drop in throughput at the same time. On the other hand, Drop Tail or Random Drop strategies are very sensitive to sudden flows; that is, the gateway queue will often overflow when packets from these flows arrive. To avoid these two phenomena, gateways can use special algorithms to detect congestion and decide which connections will be notified of congestion at the gateway. The RED gateway randomly selects incoming packets to mark; with this method, the probability of marking a packet from a particular connection is proportional to the connection's shared bandwidth at the gateway. − Another goal is to control the average queue size even without cooperation from the source entities. This can be done by dropping packets when the average size exceeds an upper threshold (instead of marking it). This approach is necessary in cases where most connections have transmission times that are less than the round-trip time, or where the source entities are not able to reduce traffic in response to marking or dropping packets (such as UDP flows). 3.2.2 Algorithm This section describes the algorithm for RED gateways. RED gateways calculate the average queue size using a low-pass filter. This average queue size is compared with two thresholds: minth and maxth. When the average queue size is less than the lower threshold, no incoming packets are marked or dropped; when the average queue size is greater than the upper threshold, all incoming packets are dropped. When the average queue size is between minth and maxth, each incoming packet is marked or dropped with a probability pa, where pa is a function of the average queue size avg; the probability of marking or dropping a packet for a particular connection is proportional to the bandwidth share of that connection at the gateway. The general algorithm for a RED gateway is described as follows: [5] For each packet arrival Caculate the average queue size avg If minth ≤ avg < maxth div.maincontent .s1 { color: black; font-family:"Times New Roman", serif; font-style: normal; font-weight: normal; text-decoration: none; font-size: 15pt; } div.maincontent .s2 { color: black; font-family:"Times New Roman", serif; font-style: normal; font-weight: bold; text-decoration: none; font-size: 15pt; } div.maincontent .p { color: black; font-family:"Times New Roman", serif; font-style: normal; font-weight: normal; text-decoration: none; font-size: 14pt; margin:0pt; } div.maincontent p { color: black; font-family:"Times New Roman", serif; font-style: normal; font-weight: normal; text-decoration: none; font-size: 14pt; margin:0pt; } div.maincontent .s3 { color: black; font-family:"Times New Roman", serif; font-style: normal; font-weight: bold; text-decoration: none; font-size: 14pt; } div.maincontent .s4 { color: black; font-family:"Times New Roman", serif; font-style: normal; font-weight: normal; text-decoration: none; font-size: 14pt; } div.maincontent .s5 { color: black; font-family:"Times New Roman", serif; font-style: italic; font-weight: normal; text-decoration: none; font-size: 14pt; } div.maincontent .s6 { color: black; font-family:"Times New Roman", serif; font-style: italic; font-weight: bold; text-decoration: none; font-size: 14pt; } div.maincontent .s7 { color: black; font-family:Wingdings; font-style: normal; font-weight: normal; text-decoration: none; font-size: 14pt; } div.maincontent .s8 { color: black; font-family:Arial, sans-serif; font-style: italic; font-weight: bold; text-decoration: none; font-size: 15pt; } div.maincontent .s9 { color: black; font-family:"Times New Roman", serif; font-style: normal; font-weight: bold; text-decoration: none; font-size: 14pt; } div.maincontent .s10 { color: black; font-family:"Times New Roman", serif; font-style: normal; font-weight: normal; text-decoration: none; font-size: 9pt; vertical-align: 6pt; } div.maincontent .s11 { color: black; font-family:"Times New Roman", serif; font-style: normal; font-weight: normal; text-decoration: none; font-size: 13pt; } div.maincontent .s12 { color: black; font-family:"Times New Roman", serif; font-style: normal; font-weight: normal; text-decoration: none; font-size: 10pt; } div.maincontent .s13 { color: black; font-family:"Times New Roman", serif; font-style: normal; font-weight: normal; text-d
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Sugar concentration (%)	Boiling temperature ( 0 C)
10	100
20	100.6
30	103.6
30	103.6
64 – 65	105

Table 3.4. Relationship between sugar concentration and boiling temperature of sucrose solution in water

The method of measuring boiling point to determine sugar concentration has a large error because the boiling point does not change much when the concentration changes. Using a hydrometer or weighing a certain volume of syrup can measure the density of the syrup. For example: 1 liter of simple sucrose syrup with a concentration of 64% at 20 0 C must have a mass of 1.314 kg.

The hydrometer type is graduated according to Baume, and is correlated with the specific gravity as shown in table 3.5:

Table 3.5. Correlation between Baume degree and specific gravity

Baume degree

Proportion	Baume degree	Proportion
28	1,2407	34.5	1,3100
29	1.2515	35	1,3202
30	1.2624	36	1,3324
31	1,2736	37	1,3448
32	1,2849	38	1,3574
33	1,2964	39	1,3703
34	1,3020	40	1,3834

How to calculate the amount of water to add to syrup with a concentration exceeding the specified limit as follows (in grams):

In there:

X = ad 2 ( d 1 d )

d 1 ( d d 2 )

X is the amount of water to add (g) a is the amount of syrup to dilute (g)

d 2 is the specific gravity of water = 1; (if using low concentration syrup with specific gravity d 2 instead of water, then X is the amount of low concentration syrup needed to add to high concentration syrup)

d1 is the density of syrup to be diluted

d is the specified density of syrup to be achieved.

When using a Baume hydrometer, the amount of water needed to dilute the syrup to the specified level is calculated according to the formula:

X = 0.033.aD

In which: X is the amount of water needed to dilute a is the amount of syrup (g)

b is the measured baume number of the syrup to be diluted exceeding 35 0 baume.

 Made in syrup:

The syrup needs to be filtered hot through several layers of gauze, special filter paper that is thick and porous, with large filter holes can be used to filter the syrup.

If starting from fruit juice or herbal extracts, clarification may be more complicated due to the colloidal precipitates. In principle, the pharmaceutical solutions need to be filtered before dissolving the sugar. If heating does not cause the colloidal precipitates to coagulate, the following clarification methods can be applied:

- Using filter paper pulp: Grind 1g of pulp into a paste in a porcelain mortar with a little hot water, pour into 1000g of hot syrup, boil for a few minutes. Then filter through cloth. This method has the advantage of not introducing foreign impurities into the syrup.

- Using egg whites: one egg white for 10 liters of syrup. Dissolve the egg white in the syrup, stir, the egg white albumin will precipitate and attract small particles suspended in the syrup that are difficult to filter. Skim off the precipitate, filter the syrup through cloth. This method has the disadvantage of introducing some small soluble protein molecules into the syrup, which can cause incompatibility with the drug.

4.2.4. Quality control - preservation

Syrups are specified with quality indicators on physical and chemical properties according to the Pharmacopoeia such as clarity, specific gravity, qualitative and quantitative identification of pharmaceutical ingredients...

For preservation, the syrup often contains antifungal and mold substances such as nipagin and nipasol (ratio 0.03 - 0.05%). Syrups are usually packaged in sealed bottles and should not be refrigerated because there may be crystallized sugar in the syrup.

4.2.5. Some examples of medicinal syrups

Prepare syrup by dissolving sugar in pharmaceutical solution.

White ant syrup ( according to DĐVN I, volume I) White ant 30g

Distilled water 500ml

1% ammonia solution 700ml White sugar 1800g

Crush the white ant wings in a porcelain mortar, put them in a porcelain bowl with a lid, add 500ml of distilled water, boil in a double boiler for 2 hours, stirring occasionally with a glass rod. Let cool, decant the water and filter through a cheesecloth.

Add 500ml of 1% ammonia solution to the residue, boil in a water bath for 1 hour, stirring occasionally. Let cool, decant, filter through cheesecloth and concentrate on the first decoction.

Extract once more with 200ml of 1% ammonia solution as above, finally pour into the concentrated decoction above to make up to 1000ml.

Add 1.8 kg of sugar to 1000 ml of decoction, cover tightly, boil in a water bath, stir occasionally until dissolved, then filter through cloth. The resulting syrup is a thick liquid, slightly brownish yellow, may be slightly cloudy, has a white ant aroma, a faint vanilla scent, and a sweet taste.

Specific gravity at 25 0 C: 1.298 – 1.32

Prepare medicinal syrup by dissolving the drug substance or drug solution into simple syrup.

Chloral syrup:

Formula: Crystallized Chloral Hydrate 5.0g Water 4.5g

Peppermint alcohol 0.5g

Single syrup 90g

Dissolve chloral hydrate in water, add peppermint alcohol, simple syrup, stir well.

Colorless, viscous liquid, minty odor, sweet, slightly bitter taste. Specific gravity about 1.306

– 1,314.

4.3. Lemon juice medicine

4.3.1. Definition

Lemonade is a solution of organic and inorganic acids and salts, sweetened, scented and sometimes with CO2 vapor , used as a beverage, containing some medicinal ingredients.

Lemon juice medicine has a common therapeutic effect, lemon juice is a bleaching medicine, lemon juice is an acid to detoxify alkali, lemon juice is an antiemetic.

4.3.2. Preparation techniques

The solvent for making lemon juice is distilled water.

The acids involved in the composition of lemon juice can be organic or inorganic acids (sulfuric acid, citric acid, etc.). Commonly used salts are magnesium citrate, sodium tartrate, potassium bitartrate. If you want lemon juice to have CO2 vapor , you can bubble CO2 into the prepared lemon juice or you can create CO2 directly in the solution by letting sodium bicarbonate react with the acid in the solution.

Lemonade is usually prepared by dissolving and mixing the ingredients in the formula. For lemonade with gas, the amount of CO2 in the solution depends on the ingredients and preparation method. If sodium bicarbonate is dissolved, then acid is dissolved, a large part of the CO2 formed will be lost.

If the sodium bicarbonate and acid solutions are prepared separately, and only mixed before use, more CO2 can be retained . However, the acid and dry sodium bicarbonate can also be mixed together in a thick-walled, dried bottle with a capacity twice the volume of the lemon juice solution to be prepared. Then add the syrup. Add water or the medicinal solution to the bottle last. Close the cap tightly.

Non-vaporous lemonades may be filtered. Vaporous lemonades are usually not filtered. If necessary, the acid and sodium bicarbonate solutions may be filtered separately before mixing.

Lemon juice solution contains a certain amount of sugar, which is a favorable environment for bacteria and mold to grow. Therefore, it should only be mixed when used. It can be stored for a day or two in a cool place.

To overcome the disadvantages of lemon juice being easily spoiled and losing CO2, effervescent granules or tablets with similar ingredients (acid, salts, sodium bicarbonate, sugar, flavoring agents, etc.) have been produced. When using, dissolve the granules or tablets in distilled water or boiled water that has cooled.

4.3.3. Some examples

Prepare lemon juice with citric acid and steam

Recipe:

- Solution 1: Sodium bicarbonate 4.0g

Single syrup 15.0g

Water 100ml

- Solution 2: Citric acid 3.5g

Citric acid syrup 15.0g

Water 100ml

In a bottle dissolve sodium bicarbonate in water then add simple syrup.

In another bottle, dissolve citric acid and add simple syrup.

When using, drink one spoon of solution 1, then drink one spoon of solution 2. Carbon dioxide is formed in the stomach, which has an anti-nausea effect.

If you want to mix (only put in one bottle), use the following formula: Citric acid 15.0g

Sodium bicarbonate 2g

Single syrup 15g

Water 100ml

Add citric acid and sodium hydrogen carbonate to the bottom of the bottle, add syrup. Then slowly and carefully add water to the bottle to avoid disturbing the syrup layer, close the cap tightly, shake before use.

4.4. Perfume

4.4.1. Definition

Perfumes are preparations obtained by distilling medicinal plants or by dissolving essential oils in water. Perfumes contain volatile active ingredients of medicinal plants such as essential oils, volatile acids (izovalerianic, cyanhydric, ...).

In pharmaceutical formulations, aromatic water is often used as a carrier or solvent for some drugs with unpleasant odors. Only some aromatic waters have pharmacological effects such as peach leaf aromatic water, peppermint aromatic water, and white almond aromatic water.

4.4.2. Preparation techniques

Fragrance preparation usually uses fresh or dried medicinal herbs containing volatile compounds or essential oils.

When storing fresh medicinal herbs, the finished product will be clear and fragrant. However, for some aromatic waters (cinnamon, cloves, etc.), good finished products can only be obtained when using dry medicinal herbs.

Volatile substances and essential oils are often found in many different parts of plants, but are most commonly found in flowers, leaves and bark. Medicinal herbs must be harvested at the right time: flowers should be harvested when they are about to bloom, leaves when the plant is about to flower or has just begun to flower, fruits when they are just beginning to ripen, and rhizomes are usually harvested when the plant is fully grown.

If you prepare perfume by dissolving essential oils in water, you must use good essential oils. Do not use essential oils that have been stored for too long, have been oxidized by the effects of air and light, or have changed.

To prepare colored perfume and change the flavor.

4.4.2.1. Steam distillation method

From fragile medicinal herbs (flowers, leaves, etc.), steam distillation is often used. Steam distillation equipment includes a steam generator, a medicinal herb container, and a condenser connected to a receiver. Steam is led from the boiling part, bubbled into the medicinal herb water, attracting essential oils and volatile aromatic substances to the condenser to form aromatic water.

The advantage of the steam distillation method is that the medicinal herbs only come into contact with steam, not the bottom of the pot, avoiding overheating which can damage the medicinal herbs and cause the aromatic water to have a burnt smell. It should be noted that before distillation, the medicinal herbs must be divided into appropriate small pieces (flowers and leaves in coarse powder; roots, seeds, and fruits ground into medium fine powder).

On a large scale, especially for solid medicinal herbs, people use the direct distillation method. Medicinal herbs and water are put directly into the pot. To prevent the medicinal herbs from coming into contact with the bottom of the pot, a tray or sieve is usually placed away from the bottom of the pot. Medicinal herbs can also be placed in a basket to be submerged in water. For solid medicinal herbs, soak the medicinal herbs in water for 24 hours before distilling.

When preparing aromatic water by distillation, it is important to note that in the initial stage, the medicinal herbs still contain a lot of essential oils, so only heat them moderately. On the other hand, the condenser must be cold enough to avoid loss of essential oils. If the distillation is done too quickly, the proportion of the ingredients will be low. Usually, the first aromatic water collected contains many hydrophilic compounds (aldehydes, alcohols, acids, etc.) and has a pleasant aroma.

The collected aromatic water needs to be shaken well, then left to stand and the undissolved essential oil (if any) is decanted using a separator. Filter the aromatic water through filter paper or cotton soaked with water.

4.4.2.2. Method of dissolving essential oils in water

Because aromatic waters obtained by distillation are often difficult to preserve and the preparation process requires time, people have used dissolution methods to quickly prepare aromatic waters.

Aromatic water can be prepared by diluting an alcohol solution of essential oils with water. The alcohol solution of essential oils is prepared according to the following formula:

Essential oil 1g

Ethanol 90 0 vđ 100ml