GLP-1 Receptor Agonists: How They Work and What They Actually Do

Semaglutide, liraglutide, dulaglutide, and tirzepatide are household names. They are also frequently described in ways that are technically wrong. This article explains the pharmacology in plain language.

1. What GLP-1 Is in the Body

Glucagon-like peptide-1 is a hormone released by L-cells in the lining of the small intestine after a meal. It is an incretin, meaning it amplifies insulin release in response to glucose. Its natural actions include stimulating insulin secretion when blood glucose is high, suppressing glucagon release, slowing gastric emptying, and signalling satiety to the brain.

Native GLP-1 has a half-life of only one to two minutes because the enzyme DPP-4 degrades it rapidly. That is why therapeutic GLP-1 receptor agonists are engineered with structural modifications to resist degradation, allowing once-daily or once-weekly dosing.

2. The Four Main Effects

When a GLP-1 receptor agonist binds its receptor, four clinically relevant things happen:

• Glucose-dependent insulin release. Insulin secretion rises when glucose is elevated, which is why hypoglycaemia is uncommon when these drugs are used alone.
• Reduced glucagon secretion. Less glucagon means less glucose released from the liver.
• Slowed gastric emptying. Food leaves the stomach more slowly, which prolongs fullness and partly explains the nausea many users experience.
• Central appetite suppression. Receptors in the hypothalamus and brainstem reduce hunger signalling and food reward.

3. Why Weight Loss Occurs

The dominant driver of weight loss is reduced energy intake, not increased energy expenditure. Patients eat less because they feel full sooner and stay full longer, and because hunger is blunted. This is an important distinction, because it explains why gastrointestinal side effects and weight loss tend to travel together.

4. Where Tirzepatide and Retatrutide Differ

Tirzepatide is a dual agonist that activates both GIP and GLP-1 receptors. Adding GIP receptor activity appears to improve tolerability and produces somewhat greater weight loss than GLP-1 alone in trials.

Retatrutide goes further, adding glucagon receptor activation to create a triple agonist. Glucagon receptor signalling raises energy expenditure, which is a mechanistically different route to weight loss. This is the main reason researchers have speculated that triple agonists might produce a different side-effect profile from single or dual agonists, including effects on heart rate and energy levels.

5. What These Drugs Do Not Do

They are not fat burners. They do not directly dissolve adipose tissue. They do not work without a reduced food intake. And they are not interchangeable: doses are not equivalent between products, and switching requires clinical oversight.

They also do not eliminate the underlying biology. When treatment stops, appetite signalling returns, and weight regain is the usual outcome unless diet and activity habits have changed.

6. Common and Serious Adverse Effects

Common effects are gastrointestinal: nausea, vomiting, diarrhoea, constipation, and abdominal discomfort. These are usually worst during dose escalation and often improve with time. Serious but uncommon risks include pancreatitis, gallbladder disease, and, in some patients, worsening of diabetic retinopathy.

Loss of lean muscle mass during rapid weight loss is a recognised concern, which is why adequate protein intake and resistance training are commonly recommended alongside treatment.

7. The Bottom Line

GLP-1 receptor agonists work by amplifying a natural satiety and glucose-regulating system. They are effective, they are not magic, and they carry real side effects that require monitoring. Understanding the mechanism makes it much easier to understand both the benefits and the limits.

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Disclaimer: This article is for informational and educational purposes only. It is not medical advice and is not a substitute for consultation with a qualified healthcare professional. Never start, stop, or change a medicine without guidance from your prescriber or pharmacist.

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References:

1. Drucker DJ. Mechanisms of action and therapeutic application of glucagon-like peptide-1. Cell Metab. 2018;27(4):740-756. doi:10.1016/j.cmet.2018.03.001
2. Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021;384(11):989-1002. doi:10.1056/NEJMoa2032183
3. Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity. N Engl J Med. 2022;387(3):205-216. doi:10.1056/NEJMoa2206038
4. Jastreboff AM, Kaplan LM, Frias JP, et al. Triple-hormone-receptor agonist retatrutide for obesity: a phase 2 trial. N Engl J Med. 2023;389(6):514-526. doi:10.1056/NEJMoa2301972

Nonapproved Retatrutide: What 150,000 Social Media Posts Reveal About Side Effects

Retatrutide is one of the most discussed experimental weight-loss drugs in the world, and it is not approved for sale anywhere. Despite that, a growing number of people are buying it online and injecting it. A study published in JAMA Network Open in October 2026 set out to find out what those people say happens to them afterwards.

1. What Is Retatrutide?

Retatrutide is an investigational once-weekly injection that activates three hormone receptors at the same time: GIP, GLP-1, and glucagon. It is the only triple agonist in its class. In a phase 2 obesity trial, participants taking 12 mg per week lost an average of up to 17.5 percent of body weight over 24 weeks, a result that generated enormous public interest. Phase 3 trials are still running, which means no regulator has yet assessed the drug for safety and efficacy.

Because retatrutide is not approved, it cannot be legally sold as a medicine. Products containing it are nevertheless marketed directly to consumers, often labelled “for research use only” or “not for human consumption” to sidestep regulation.

2. How the Study Was Done

Researchers at the University of Pennsylvania collected 148,640 retatrutide-related posts and comments from 38,936 users across 27 Reddit communities focused on retatrutide, peptides, and weight management, covering May 2021 to December 2025. A large language model classified which users described personal use, extracted the symptoms those users attributed to the drug, and mapped each symptom to a Medical Dictionary for Regulatory Activities (MedDRA) Preferred Term.

The team manually validated 100 posts and reported high precision and recall. After excluding weight-loss and appetite-suppression terms, 7,823 users formed the analytic group.

3. The Most Commonly Reported Symptoms

The leading reported terms were not the ones clinicians would expect. The most frequent were:

• Increased appetite – 17.1 percent
• Fatigue – 15.2 percent
• Increased energy – 12.4 percent
• Nausea – 11.6 percent
• Food craving – 7.3 percent
• Insomnia – 6.1 percent
• Increased heart rate – 4.8 percent

Muscle-related complaints such as muscle hypertrophy, myalgia, and muscle atrophy were also notably common, and tachycardia was reported by 3.8 percent of users.

4. How This Differed From Clinical Trial Data

In the phase 2 trial, gastrointestinal events such as nausea, diarrhoea, vomiting, and constipation were the most common adverse events. In the social media data, gastrointestinal symptoms were present but not dominant. Comparing the two datasets descriptively, retatrutide discussion clustered more around appetite, general-system, muscle, sleep, and heart-rate categories, while semaglutide and tirzepatide discussion clustered more around nausea, vomiting, and reduced gut motility.

The authors suggest the difference may relate to retatrutide’s glucagon receptor activity. Glucagon receptor signalling increases energy expenditure, which could plausibly explain reports of increased energy, raised heart rate, and altered appetite. The authors are careful to note that this remains a hypothesis.

5. Why “Increased Appetite” Is the Most Interesting Finding

It sounds contradictory: a drug that produces substantial weight loss, with users reporting that it makes them hungrier. Several explanations are possible, and the study cannot separate them. The product being injected may not be retatrutide at all. The dose may be wrong. Users may be stacking several unapproved peptides at once. The population is unusual, skewing towards bodybuilding and fitness communities. And people who experience a striking symptom are more likely to post about it.

6. What This Study Cannot Tell Us

The authors state plainly that the analysis cannot assess incidence, causality, dose-response, or comparative safety against approved GLP-1 medicines. Product identity, purity, dose, route, treatment duration, and medical history could not be verified for any user. The findings are explicitly described as hypothesis-generating.

In other words, this is a signal, not a verdict. It tells regulators and clinicians where to look. It does not tell anyone what retatrutide does.

7. What Pharmacists and Patients Should Take From It

For health professionals, the practical message is that patients may be using compounds that never appear in their medication record. The authors recommend non-judgemental screening for nonapproved peptide use, counselling about unknown product quality, and reporting suspected adverse events to national pharmacovigilance systems such as MedWatch.

For patients, the message is simpler. A drug sold without approval has no guaranteed identity, no guaranteed dose, and no safety monitoring. Reported experiences on social media are not evidence of what a medicine does, and the people posting are not a representative sample of anyone.

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Disclaimer: This article is for informational and educational purposes only. It is not medical advice and is not a substitute for consultation with a qualified healthcare professional. Never start, stop, or change a medicine without guidance from your prescriber or pharmacist.

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References:

1. Sehgal NKR, Tronieri JS, Rader B, Ungar L, Guntuku SC. Self-Reported Adverse Effects Among Social Media Users Taking Nonapproved Retatrutide. JAMA Netw Open. 2026;9(10):e2638929. doi:10.1001/jamanetworkopen.2026.38929
2. Jastreboff AM, Kaplan LM, Frias JP, et al. Triple-hormone-receptor agonist retatrutide for obesity: a phase 2 trial. N Engl J Med. 2023;389(6):514-526. doi:10.1056/NEJMoa2301972
3. Nagem Lopes LP, Ramos-Silva A, Gallo de Castro A, Correa de Matos G. Potential utility of social media in pharmacovigilance to identify adverse events and safety signals: a scoping review. Res Social Adm Pharm. 2026;22(5):617-624. doi:10.1016/j.sapharm.2026.02.003
4. Sehgal NKR, Tronieri JS, Ungar L, Guntuku SC. Self-reported side effects of semaglutide and tirzepatide in online communities. Nature Health. 2026;1(8):806-811. doi:10.1038/s44360-026-00108-y
5. US Food and Drug Administration. Medications containing semaglutide marketed for type 2 diabetes or weight loss. FDA.gov. Accessed October 2026. https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/medications-containing-semaglutide-marketed-type-2-diabetes-or-weight-loss

Common Side Effects of Pain Relievers: Safety, Risks, and What to Watch For

Pain relievers, also known as analgesics, are among the most widely used medications globally. They work through different mechanisms, and each class carries unique side effects.

Understanding these differences is essential for safe use and effective pain management.

1. Overview of Pain Relievers

Pain relievers, also known as analgesics, are among the most widely used medications globally. They work through different mechanisms, and each class carries unique side effects. The major categories include NSAIDs, acetaminophen, and opioids.

2. NSAIDs: Common Side Effects

Nonsteroidal anti-inflammatory drugs, such as ibuprofen, naproxen, and aspirin, reduce inflammation and pain. Their most common side effects include stomach upset, heartburn, and nausea. Long-term use increases the risk of gastrointestinal bleeding and ulcers. NSAIDs can also raise blood pressure, affect kidney function, and increase cardiovascular risk.

3. Acetaminophen: Liver Safety

Acetaminophen is effective for pain and fever but carries a significant risk to the liver. Doses exceeding 4,000 milligrams per day can cause severe liver damage. Many combination cold and flu products contain acetaminophen, which can lead to unintentional overdose.

4. Opioids: Serious Risks

Opioids are reserved for severe pain but carry a high risk of dependence, tolerance, and overdose. Common side effects include constipation, drowsiness, nausea, and dizziness. Respiratory depression is the most dangerous side effect and can be fatal in overdose.

5. Managing Common Side Effects

To minimize stomach upset, take NSAIDs with food and consider a protective medication if recommended by a doctor. For constipation from opioids, increase fiber intake and hydration. If drowsiness occurs, avoid driving and alcohol.

6. Special Precautions

Certain groups, including older adults, pregnant individuals, and those with kidney, liver, or stomach conditions, should exercise extra caution. Always consult a healthcare provider before combining pain relievers with other medications.

7. Key Takeaways

NSAIDs commonly cause stomach and cardiovascular issues. Acetaminophen can cause liver damage in high doses. Opioids carry significant risks of dependence and respiratory depression. Use the lowest effective dose for the shortest time.

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Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. Always consult a healthcare provider before using pain relievers, especially if you have underlying health conditions or take other medications.

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References:

1. U.S. Food and Drug Administration (FDA). "Know the Facts About Pain Relievers." fda.gov
2. National Institutes of Health (NIH). "Acetaminophen and Liver Safety." nih.gov
3. American College of Gastroenterology. "NSAIDs and Gastrointestinal Risk." gi.org

How to Read Medication Labels: A Step-by-Step Guide for Safe Use

Medication labels contain essential information that ensures safe and effective use. Taking a few extra minutes to read the label can prevent serious harm.

According to the National Institutes of Health (NIH), medication errors often occur because patients do not fully understand label instructions.

1. Why Reading Labels Matters

Medication labels contain essential information that ensures safe and effective use. Taking a few extra minutes to read the label can prevent serious harm.

2. Understanding the Drug Facts Panel

The Drug Facts panel, required on most OTC medications, is organized in a standard format. It lists the active ingredient, which is the component that treats the condition. The inactive ingredients are also listed.

3. Active Ingredients and Their Doses

The active ingredient section shows what the medication contains and the strength per dose. Some products contain multiple active ingredients. Pay close attention to the ingredient that matches your symptoms.

4. Dosage and Directions

The directions section specifies how much to take, how often, and for how long. Never extend use beyond the labeled duration. If symptoms persist, consult a healthcare provider.

5. Warning and Precaution Sections

Warnings highlight serious risks, including who should not use the product, potential side effects, and necessary precautions. Look for warnings about pregnancy, liver disease, kidney disease, or drug interactions.

6. Expiration Dates and Storage

The expiration date ensures the medication remains effective and safe. After expiration, the drug's potency and chemical stability decline. Storage instructions on the label, such as refrigeration requirements, also matter.

7. Special Populations and Pediatric Dosing

Some labels provide specific dosing for children or older adults. Always use the dosing device provided, such as a dropper or measuring cup, rather than kitchen spoons.

8. Key Takeaways

Read every label before use. Check active ingredients, dosing, warnings, and expiration. Store medications properly. Consult a pharmacist before combining multiple products.

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Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. Always consult a healthcare provider or pharmacist regarding medication labels and use.

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References:

1. U.S. Food and Drug Administration (FDA). "How to Understand and Use the Drug Facts Label." fda.gov
2. National Institutes of Health (NIH). "Reading Medicine Labels." nih.gov
3. Consumer Reports. "How to Read a Drug Label." consumerreports.org

OTC vs Prescription Medications: Differences, Safety, and When to Use Each

Over-the-counter (OTC) medications are sold without a prescription and are intended for self-treatment of minor conditions. Prescription medications, on the other hand, require a healthcare provider's authorization and are used for more serious or complex conditions.

The distinction reflects differences in proven risk, severity of conditions treated, and the need for medical supervision.

1. Defining OTC and Prescription Medications

OTC medications are sold without a prescription and are intended for self-treatment of minor conditions. Prescription medications require a healthcare provider's authorization. The distinction reflects differences in proven risk, severity of conditions treated, and the need for medical supervision.

2. Regulation and Safety Standards

Both categories undergo rigorous FDA evaluation, but prescription drugs face more stringent clinical trial requirements due to their higher-risk, higher-benefit profile. OTC drugs must prove they are safe for self-diagnosis and self-treatment.

3. When Self-Treatment With OTC Is Appropriate

OTC medications are appropriate for short-term relief of common symptoms such as headaches, mild allergies, heartburn, and minor aches. They are effective when symptoms are clearly identified and match typical presentations. Serious or persistent symptoms should never be self-treated with OTC products.

4. Risks of Using Prescription Medications Without a Prescription

Using prescription medications without medical supervision can lead to severe adverse effects, incorrect dosing, drug interactions, and masking of serious conditions. This practice is also illegal and contributes to the dangerous trend of medication misuse and antibiotic resistance.

5. How to Use OTC Safely

Read the Drug Facts label carefully before each use. Pay attention to active ingredients, warnings, dosage, and expiration dates. Never exceed the recommended dose, and do not combine multiple products with the same active ingredient.

6. The Role of a Pharmacist

Pharmacists are medication experts trained to evaluate whether a chosen OTC product is appropriate for your health profile. They can identify drug interactions, recommend the right strength, and advise on side effects.

7. Key Takeaways

OTC medications are for self-treatment of minor, temporary conditions. Prescription medications require medical supervision for higher-risk conditions. Both require careful use. Read labels, avoid duplication, and consult a pharmacist or doctor when symptoms are unclear, persistent, or complex.

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Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. Always consult a healthcare provider for guidance on the appropriate medication for your condition.

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References:

1. U.S. Food and Drug Administration (FDA). "Over-the-Counter Medicines." fda.gov
2. Centers for Disease Control and Prevention (CDC). "Get the Facts on Prescription Drug Safety." cdc.gov
3. National Institutes of Health (NIH). "OTC vs Prescription: What's the Difference?" nih.gov

Top Drug Interactions You Should Know: A Pharmacy Safety Guide

A drug interaction occurs when one substance affects the activity, effectiveness, or safety of a medication. Interactions can happen between prescription drugs, over-the-counter (OTC) products, herbal supplements, and even certain foods. Some interactions reduce a drug's effectiveness, while others can cause dangerous side effects or toxicity.

The World Health Organization (WHO) identifies drug interactions as a leading cause of preventable adverse drug events worldwide. Understanding the most common interactions is essential for safe medication use.

1. The Most Common Interaction: Warfarin and Vitamin K

Warfarin, a blood-thinning medication, is highly sensitive to vitamin K intake. Patients on warfarin must maintain a consistent vitamin K intake because sudden increases can lower the drug's effectiveness, increasing clot risk. Leafy green vegetables such as spinach, kale, and broccoli are rich in vitamin K. Consistency, not avoidance, is the key.

2. Pain Relievers and Bleeding Risk

Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and aspirin increase bleeding risk, especially when taken with anticoagulants or antiplatelet drugs. Combining these medications can lead to gastrointestinal bleeding or bruising.

3. Antibiotics and Dairy Products

Certain antibiotics, including ciprofloxacin and doxycycline, bind to calcium, magnesium, and aluminum found in dairy products. This binding prevents proper absorption, reducing the drug's effectiveness. Patients should separate antibiotic doses from dairy by at least two hours.

4. Grapefruit and Statin Medications

Grapefruit and grapefruit juice contain furanocoumarins that inhibit the enzyme CYP3A4 in the liver and intestine. This inhibition can cause statins, calcium channel blockers, and other drugs to accumulate to toxic levels in the blood. Patients taking simvastatin or atorvastatin should avoid grapefruit entirely.

5. Herbal Supplements and Prescription Drugs

Herbal supplements are not regulated as strictly as pharmaceuticals and can interact with prescription medications. St. John's Wort reduces the effectiveness of birth control pills, anticoagulants, and some antidepressants. Ginkgo biloba and garlic supplements can increase bleeding risk when combined with blood thinners.

6. How to Prevent Drug Interactions

Always maintain a complete, updated list of all medications, supplements, and OTC products you use. Share this list with every healthcare provider you visit. Use a single pharmacy for all prescriptions so pharmacists can screen for interactions. Ask your pharmacist, "Are there any interactions with what I currently take?" before adding new medications or supplements.

7. When to Seek Medical Attention

Seek immediate medical help if you experience unusual bleeding, severe dizziness, new rashes, or worsening symptoms after starting a new medication or supplement. Some interactions develop slowly and cause subtle damage over time, making regular check-ups essential.

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Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a licensed healthcare professional before combining medications, supplements, or changing your diet.

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References:

1. U.S. Food and Drug Administration (FDA). "Drug Interactions: What You Should Know." fda.gov
2. National Institutes of Health (NIH). "Drug Interactions." nih.gov
3. Mayo Clinic. "Drug Interaction: What Is It and How to Avoid It." mayoclinic.org

How to Store Medications at Home: A Complete Safety Guide

Proper medication storage is a critical part of safe healthcare that many households overlook. Medications are sensitive chemical compounds that can degrade when exposed to heat, moisture, light, or air.

When stored incorrectly, pills may lose their potency, making them less effective when you genuinely need them. In some cases, improperly stored medications can become unsafe to consume. According to the U.S. Food and Drug Administration (FDA), drug degradation caused by poor storage conditions is a documented contributor to medication failures, particularly for antibiotics and life-sustaining drugs.

1. Why Proper Medication Storage Matters

Proper medication storage is a critical part of safe healthcare that many households overlook. Medications are sensitive chemical compounds that can degrade when exposed to heat, moisture, light, or air.

When stored incorrectly, pills may lose their potency, making them less effective when you genuinely need them. In some cases, improperly stored medications can become unsafe to consume. According to the FDA, drug degradation caused by poor storage conditions is a documented contributor to medication failures, particularly for antibiotics and life-sustaining drugs.

2. Ideal Temperature and Environment

Most medications should be stored at controlled room temperature, typically between 20°C and 25°C, away from direct sunlight. The kitchen and bathroom are common but problematic storage areas because of fluctuating humidity and heat. A cool, dry cabinet in a bedroom or living room is generally the safest option.

Extreme temperatures above 30°C can accelerate chemical breakdown, which is why medications should never be left in a hot car or near a stove.

3. Protecting Medications from Light and Moisture

Light-sensitive medications require opaque or amber-colored containers. Moisture is another enemy of drug stability; this is why many medications come with silica gel desiccants in their packaging. Keep medications in their original, labeled packaging until the moment of use.

4. Child-Resistant and Senior-Safe Storage

Medications should be stored in a location that is both out of reach and out of sight of children and pets. Child-resistant caps must always be replaced securely after use.

5. Travel and Emergency Storage Guidelines

When traveling, medications should remain in their original containers and carried in carry-on luggage. Insulated pill cases with temperature controls are available for long trips.

6. Safe Disposal of Expired or Unused Medications

Expired medications lose effectiveness and may pose health risks. The safest disposal method is through FDA-approved drug take-back programs or community pharmacy drop-off locations.

7. Key Takeaways for Medication Storage

Store medications at room temperature in a cool, dry, and dark location. Keep them in original packaging with desiccants. Protect from children and pets. Dispose of expired drugs through approved take-back programs.

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Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice. Always read and follow the storage instructions provided by your pharmacist or the medication label. Consult a healthcare provider for medication-specific guidance.

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References:

1. U.S. Food and Drug Administration (FDA). "Drug Product Storage." fda.gov
2. National Institutes of Health (NIH). "Storing Your Medicines." nih.gov
3. Mayo Clinic. "Medication Safety: How to Store and Dispose of Medicines." mayoclinic.org

LAPORAN PRAKTIKUM KIMIA FARMASI ANALISIS II “Penentuan kadar Amoksilin dalam sediaan serbuk dengan Spektrofotometri UV-VIS”

LAPORAN PRAKTIKUM

KIMIA FARMASI ANALISIS II

“Penentuan kadar Amoksilin  dalam sediaan serbuk

dengan Spektrofotometri UV-VIS”

Disusun Oleh :

Kelompok 14

FARMASI 3B

Dani Ramdani      (31114064)

Dede Rizwan        (31114066)

Dita Rahmartya P.(31113071)

PRORGAM STUDI S1 FARMASI

STIKes BAKTI TUNAS HUSADA TASIKMALAYA

2017

A.    Tanggal Percobaan

Selasa, 11 Maret2017

B.     No. Sampel

5 B

C.    Tujuan

Mahasiswa mampu menetapkan kadar amoksilin dengan metode spektrosfotometri UV-VIS

D.    Prinsip Percobaan    

Spektrofotometri hukum lamberf-Bears, spektrofotometri UV-VIS digunakan untuk analis kuantitatif, nilai absorpsi berbanding lurus dengan absorpsi cahaya, ketebalan kuvet, dan konsentrasi analit, Rumus : A = a.b.c

Spektrofotometri UV-VIS menggunakan sumber cahaya dari sinar UV dan sinar tampak dengan pengaturan berkas cahaya menggunakan monokromator, spektrofotometer tersusun atas sumber spektrum yang continue, monokromator, sel absorpsi untuk larutan sampel atau blanko dan suatu alat untuk mengukur perbedaan absorbansi antara sampel dan blanko ataupun pembanding.

E.     Dasar Teori

Amoxicillin adalah antibiotika yang termasuk ke dalam golongan penisilin. Obat lain yang termasuk ke dalam golongan ini antara lain ampicillin, piperacillin, ticarcilin, dan lain-lain. Karena berada dalam satu golongan maka semua obat tersebut mempunyai mekanisme kerja yang mirip. Obat ini tidak membunuh bakteri secara langsung tetapi dengan cara mencegah bakteri membentuk semacam lapisan yang melekat disekujur tubuhnya. Lapisan ini bagi bakteri berfungsi sangat vital yaitu untuk melindungi bakteri dari perubahan lingkungan dan menjaga agar tubuh bakteri tidak tercerai berai. Bakteri tidak akan mampu bertahan hidup tanpa adanya lapisan ini. Amoxicillin sangat efektif untuk beberapa bakteri seperti h.influenzae, n.gonorrhoea, e.coli, peneumococci, streptococci, dan beberapa strain dari staphylococci (Rohman, 2007).

Sesuai dengan mekanisme kerja diatas maka amoxicillin seharusnya digunakan untuk mengobati penyakit-penyakit yang disebabkan oleh kuman-kuman yang sensitive terhadap amoxicillin. Beberapa penyakit yang biasa diobati dengan amoxicillin antara lain infeksi pada telinga tengah, radang tongsil, radang tenggorokan, radang pada laring, bronchitis, feneumonia, infeksi saluran kemih, dan infeksi pada kulit. Amoxicillin juga bisa digunakan untuk mengobati gonorrhea.

Untuk menjaga khasiat obat ini, maka harus pula diperhatikan cara penyimpanannya. Amoxicillin sebaiknya disimpan dalam suhu kamar yaitu antara 20-25°C. untuk sirup kering yang telah dicampur dengan air sebaiknya tidak digunakan lagi setalah 14 hari atau 2 minggu. Amoxicillin bisa diminum baik sebelum maupun setelah makan onbat ini sangat jarang ditemukan berinteraksi dengan obat-obat yang lain. Amoxicillin juga aman diberikan tuntuk ibu hamil dan menyusui walaupun ada beberapa kasus diare yang terjadi pada bayi yang disusui oleh ibu yang minum amoxicillin (Rohman, 2007).

Efek samping dari amoxicillin antara lain: diare, gangguan tidur, rasa terbakar di dada, mual, gatal, muntah, gelisah, nyeri perut, pendarahan dapat merusak enamel gigi bayi secara permanen.

F.     Monografi Bahan

1.      Amoxicillinum (Ditjen POM, 1995 )

Sinonim                 : Amoksilin

BM                        : 419,45

Pemerian               : Serbuk hablur, putih, praktis tidak berbau.

Kelarutan              : Sukar larut dalam air dan metanol, tidak larut dalam benzena, dalam karbon tetraklorida dan dalam kloroform.

Penyimpanan         :    Dalam wadah tertutup rapat

Kegunaan              :    Antibiotik.

2.      Aetthanolum (Dirjen POM, 1979).

Nama resmi           :  Etil alkohol

Berat molekul        :  46, 07

Pemerian              : Cairan mudah menguap, jernih, tidak berwarna, bau khas dan menyebabkan rasa terbakar pada lidah.

Kelarutan              :  Larut dalam air dan praktis tidak larut dalam pelarut organik

G.    Alat dan Bahan

1.      Alat

·           Corong

·           Gelas kimia

·           Gelas ukur

·           Labu ukur 50 mL

·           Labu ukur 5 mL

·           Pipet volume 10 mL

·           Tabung sentrifugasi

·           Vortex

·           Kaki tiga dan kasa asbes

·           Spirtus

·           Kuvet

·           Pump pipet

2.      Bahan

·           Etanol

·           Sampel Amoksilin

·           HNO₃           

H.    Prosedur

1.      Isolasi sampel

2.      Pembuatan Larutan Stok

 

3.      Pembuatan kurva kalibrasi

                                                                                                   

4           Penetapan kadar analit

 

I.       Data Hasil Pengamatan

Konsentrasi (ppm)	Absorbansi (ppm)
10	0,238
15	0,377
20	0,445
25	0,574
30	0,742
35	0,852

J.      PERHITUNGAN

1)   Pembuatan Larutan Standar Amoksilin

1)      Pembuatan Larutan Amoksilin (teknis) 500 ppm dalam 25 mL

2)      Pengenceran larutan standar dari 500 ppm

a.       10 ppm dalam 10 mL

                              V₁ x N₁  = V₂ x N₂

                                      V₁ x 500 ppm  = 10 mL x 10 ppm

                                             V₁ = 0.2 mL

b.      15 ppm dalam 10 mL

                  V₁ x N   = V₂ x N₂

              V₁ x 500 ppm  = 10 mL x 15 ppm

                                                         V₁ = 0.3 mL

c.       20 ppm dalam 10 mL

                  V₁ x N   = V₂ x N₂

              V₁ x 500 ppm  = 10 mL x 20 ppm

                                                         V₁ = 0.4 mL

d.      25 ppm dalam 10 mL

                  V₁ x N   = V₂ x N₂

              V₁ x 500 ppm  = 10 mL x 25 ppm

                                                         V₁ = 0.5 mL

e.       30 ppm dalam 10 mL

                  V₁ x N₁  = V₂ x N₂

              V₁ x 500 ppm  = 10 mL x 30 ppm

                                                         V₁ = 0.6 mL

f.       35 ppm dalam 10 mL

                  V₁ x N₁ = V₂ x N₂

      V₁ x 500 ppm   = 10 mL x 35 ppm

                  V₁         = 0,7 mL

                       

3). Menentukan kadar Amoksilin

      Regresi linear kurva kalibrasi              = y = 0,0238x  - 0,0012

      Absorbansi amoksilin                          = 0,466

      Pengenceran                                        = 500 kali

diketahui y = 0,466    b = 0,0238    a = - 00,0012

                y  = bx + a

         0,466  = 0,0238x - 0,001

      0,0238x = 0,466 + 0,001

                 x =

          x = 19,62 x 500 (pengenceran)

                 x = 9810 ppm

Kadar dalam 50 mL

               x 9810 = 490,5 mg = 0,4905 g

% Kadar analit =  x 100%

                         =  x 100% = 24,52%

K.    PEMBAHASAN

Amoksilin yang akan ditentukan kadarnya berada dalam suatu sediaan farmasi dengan menggunakan metode Spektrofotometri UV-Vis. Metode Spektrofotometri UV-Vis digunakan untuk menentukan kadar amoksilin karena dalam struktur kimia terdapat gugus kromofor dan ausokrom. Dimana gugus kromofor yang terdapat pada struktur amoksilin mampu menyerap sinar UV-Vis.

Gugus kromofor  pada amoksilin terdapat pada lingkaran merah berupa gugus C=C, C=O, dan gugus benzen sedangkan pada ausokrom terdapat pada lingkaran berwarna biru berupa gugus hidroksi dan amina.

Prinsip percobaan ini yaitu ketika amoxilin dilarutkan dalam etanol dan dianalisis dengan Spektrofotometer UV-Vis, maka gugus kromofor yang terdapat pada amoksilin akan mengabsorpsi sinar elektromagnetik dengan panjang gelombang tertentu. Sehingga nilai absorbansinya dapat diketahui dan kadar dari nipagin dapat dihitung.

Isolasi amoksilin dilakukan untuk memisahkan analit-analit dari komponen-komponen matriks yang mengganggu pada saat kuantifikasi atau deteksi analit. Pelarut organik yang digunakan untuk isolasi amoksiln yaitu etanol. Pemilihan pelarut ini didasarkan pada sifat amoksilin yang dapat larut dalam etanol, sedangkan matriksnya tidak dapat larut dalam etanol sehingga analit dapat memisah dengan sempurna.

Pengujian secara kualitatif dilakukan dengan menggunakan reaksi warna peraksi yang digunakan yaitu HNO₃ yang akan memberikan warna coklat. Pengujian ini digunakan untuk menentukan keberadaan sampel pada filtrat agar isolasi yang dilakukan sempurna tanpa adanya matriks.

Untuk analisis menggunakan spektofotometri UV-Vis sebelumnya blanko etanol 96% diukur absorbansinya terlebih dahulu. Tujuannya sebagai baseline agar etanol tidak terdeteksi. Selanjutnya dilakukan scanning untuk mencari panjang gelombang maksimum dari sampel amoxilin. Setelah ditemukan panjang gelombang maksimumnya, kemudian pembakuan dan analisis sampel amoksilin dapat dilakukan.

Dari hasil rentang absorbansi nipagin dapat dihitung persamaan regresi liniernya kemudian dapat dihitung pula kadar sampel nipagin. Dari hasil perhitungan didapat sampel no. 5 B mempunyai kadar nipagin sebesar 24.52%

L.     Kesimpulan

Berdasarkan perocbaan yang telah dilakukan, bahwa dalam penetuan metode untuk melakukan analisis suatu senyawa harus diketahui terlebih dahulu sifat fisikokimia senyawa tersebut. Dan sampel no 5 B yang berbentuk serbuk mengandung amoksilin dengan kadar 24,52% yang dianalisis menggunakan metode spektrofotometri Uv-vis.

M.   Daftar Pustaka

Ditjen POM. (1989). Materia Medika Indonesia, Jilid V. Jakarta: Depkes RI.

Ditjen POM. (1995). Materia Medika Indonesia, Jilid VI. Jakarta: Departemen Kesehatan Republik Indonesia.

Katzung, B.G. 2001. Farmakologi Dasar dan Klinik, edisi ke-8. Jakarta: Salemba Medika.

Kementrian Kesehatan Republik Indonesia. 2014. Farmakope Indonesia Edisi V. Jakarta: Kemetrian Kesehatan RI.

Rohman, A. 2007. Kimia Farmasi Analisis. Yogyakarta: Pustaka Pelajar

Soedjadi dan Abdul Rohman. 2008. Analisis Kuantitatif Obat. Yogyakarta: Gadjah Mada University Press.

Watson, David G. 2007. Analisis Farmasi Edisi 2. Jakarta : Buku Kedokteran EGC.

Zega,M.K. 2009. Penetapan Kadar Tablet Antalgin Secara Titrasi Iodimetri di PT. Kimia Farma (PERSERO) Tbk. Plant Medan. Skripsi Fakultas Farmasi Universitas Sumatera Utara.

Puspitasari, indarini Dwi. 2014. Kimia Analitik Dasar. Bandung:  Alfabeta.