RECENT MAJOR CHANGES

American Journal of Analytical Chemistry, 3, 59-66.

doi: 10.4236/ajac.2012.31009. Vardenafil and other ED drugs inhibit phosphodiesterase type 5 (PDE-5) enzyme, which in turn maintains higher levels of cyclic guanosine monophosphate, which relaxes smooth muscles, promotes penile blood flow, and enhances erectile function [1,2]. Pharmalogical studies indicate that interaction between PDE-5 inhibitors and certain drugs containing nitrates may drastically lower blood pressure [4]. Despite the efficacy of PDE-5 inhibitors as a treatment for ED, their draw backs are also notable.

• Liquid Levitra helps men achieve and maintain erections.
• It usually starts working within 15-30 minutes.
• Dose should be guided by a healthcare provider.

Adverse effects such as head ache, facial flushing, dyspepsia, visual disturbances and muscle aches have been reported [3]. Recently, reports of blind ness have implicated Viagra [5]. A few HPLC methods determination of vardenafil in bulk drug and biological samples were reported in the literature [6- 10]. All the above methods developed (references [6-10]) for the quantification of vardenafil and other PDE-5 inhibitors employed complex analytical instruments such as mass spectrophotometer for their estimation mainly in dietary supplements and bulk drug powders.

What other drugs will affect vardenafil?

Tell your healthcare provider if you have any of the following. Heart problems, such as heart rhythm problems, chest pain, or heart failure Heart attack, stroke, or heart surgery within the past six months High blood pressure that is still too high despite taking medicines for it Peyronie's disease, or a penis with an abnormal curve or shape An erection lasting longer than four hours A blood disorder, such as sickle cell anemia An inherited eye disease called retinitis pigmentosa Vision loss, or a problem with the nerve between your eyes and brain (optic nerve) Health conditions or factors that raise the risk of optic nerve problems, such as diabetes, high cholesterol, smoking, being older than 50, or having a “crowded disc,” which is something an eye doctor may see during an eye exam Pulmonary veno-occlusive disease, a condition where blood vessels in the lungs are blocked People who can become pregnant are not usually prescribed vardenafil. It is not known if or how vardenafil could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant. People who can breastfeed are not usually prescribed vardenafil.

Vascular damage

It is not known if vardenafil passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Grapefruit or grapefruit juice can raise vardenafil levels in your body, which can increase the risk of side effects. Vardenafil orally disintegrating tablets should not be taken with water or liquids. Let it dissolve on your tongue without crushing it. As far as we are aware there is stability indicating UPLC method for the determination of related substances and for quantitative estimation of vardenafil. Hence, an attempt has been made to develop an accurate, rapid, specific and reproducible method for determination of vardenafil and all four impurities in bulk drug samples and in pharmaceutical dosage forms along with method validation as per ICH norms [11-13].

The stability tests were also performed on both drug substances and drug products as per ICH norms [14-16]. Samples of vardenafil HCl and its related impurities were received from Chiral Solutions private Limited. Hyderabad, India (Figure 1).Commercially available 20 mg vardenafil tablets (Levitra) were purchased. LC grade acetonitrile was purchased from Merck, Darmstadt, Germany. Analytical reagent grade Ammonium Bi carbonate were also purchased from Merck. High purity water was prepared by using a Millipore Milli-Q plus water purification system.

ED Medications: Cialis, Levitra, Viagra

Effective chromatographic separation was achieved on a C18 stationary phase with simple mobile phase combination delivered in a simple gradient pro- gramme and quantitation was by ultraviolet detection at 210 nm. The mobile phase consisted of a buffer and acetonitrile delivered at a flow rate 0.25 ml?min–1. Buffer consisted of 20 mM Ammonium bi carbonate, pH adjusted to 5.0 by using ortho Phosphoric acid. In the developed UPLC method the resolution (Rs) between vardenafil and its four potential impurities was found to be grater than 2.0.Regrreation analysis showed an r value (correlation coefficient) grater than 0.999 for vardenafil and its four impurities. The inter and intra day precision values for all four impurities and for vardenafil was found to be with in 2.0% RSD.

Multi-Interface polarization engineering constructed 1T-2H MoS2 QDs/Y-NaBi(MoO4)2 multiple heterostructure for high-efficient piezoelectric-photoelectrocatalysis PDE-5i degradation

The method showed good and consistent recoveries for vardenafil in bulk drugs (98.8% - 100.9%), pharmaceutical dosage forms (100.5% - 101.5%) and its all four impurities (99.8% - 102.5%).The test solutions was found to stable in acetonitrile for 48 h. The drug was subjected to stress conditions of hydrolysis, oxidation, photolysis, and thermal degradation. Considerable degradation was found to occur in peroxide hydrolysis. The stress samples were assayed against a qualified reference standard and the mass balance was found close to 99.9%. The developed RP-LC method was validated with respect to linearity, accuracy, precision and robustness. All samples and impurities used in this study were greater than 99.5% purity analyse by UPLC. The UPLC system, used for method development, forced degradation studies and method validation was a Waters Accquity Quaternary pump plus auto sampler and a photodiode array detector (MA, USA).The out put signal was monitored and processed using Empower software on Pentium computer (Digital Equipment Co). Photo stability studies were carried out in a photo stability chamber (sanyo, Leicestershine, UK).Thermal stability studies were performed in a dry air oven (Merck Pharmatech, Hyderabad, India).

16.1 How Supplied

There are no known interactions between vardenafil and alcohol. Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. In particular, make sure that you discuss if you are using any of the following before taking vardenafil. Tell your healthcare provider about all medicines that you take or have recently taken. This may not be a complete list of medicines that can interact with vardenafil.

Chromatographic conditions

If you or someone else has taken too much vardenafil, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222. Take it as your healthcare provider recommends, which is usually about one hour before planned sexual activity. Do not take levitra no prescription online double or extra doses. This survey is being conducted by the WebMD marketing sciences department. A Validated Rapid Stability-Indicating Method for the Determination of Related Substances in Vardenafil Hydrochloride by Ultra-Performance Liquid Chromatography () Kishore Kumar Kakumani, Kameswara Rao Chimalakonda, Rama Koti Reddy Yarram, Mukkanti Khagga DOI: 10.4236/ajac.2012.31009 PDF HTML 6,702 Downloads 13,358 Views Citations DOI: 10.4236/ajac.2012.31009 PDF HTML 6,702 Downloads 13,358 Views Citations A novel, sensitive, stability indicating RP-LC method has been developed for the quantitative determination of Varde- nafil and its related impurities in both bulk drugs and Pharmaceutical dosage forms. The chromatographic column used was a Zorbax Extended C18 (100 × 2.1) mm with 1.8 µm particles. The mobile phase consisted of a mixture of buffer, acetonitrile. Buffer consists of 20 mM Ammonium bi carbonate pH adjusted to 5.0 with Ortho Phosphoric acid. The column temperature was maintained at 25˚C and the detection was monitored at a wave length of 210 nm .The injection volume 2 µl.

Storing and Disposing of Your Home Medical Sharps

Vardenafil belongs to a group of medicines, known as phosphodiesterase-5 (PDE-5) inhibitors, which are used to treat erectile dysfunction or pulmonary arterial hypertension. You should not take more than one PDE-5 inhibitor medicine. Medicines in this group include avanafil (Stendra), sildenafil (Viagra, Revatio, and others), tadalafil (Cialis and others), and vardenafil (Levitra, Staxyn). Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if vardenafil is right for you.

Before taking vardenafil,

In particular, make sure that you discuss any of the following. Phenylalanine is found in vardenafil oral tablets and vardenafil orally disintegrating tablets. This substance can be harmful to people with PKU. Tell your healthcare provider if you have PKU. They can suggest a different treatment option for you. A stock solution of vardenafil (500 µg·ml–1) was prepared by dissolving an appropriate amount in acetonitrile.

• Common side effects include headache and flushing.
• Serious side effects require immediate medical attention.
• Hydration can reduce some minor side effects.

Working solutions were prepared from above stock solution for related substances determination and assay determination, respectively. A stock solution of impurities (mixture of imp-A, imp-B, imp-C and imp-D) at a concentration of 0.3 mg·ml–1 was also prepared in acetonitrile. Twenty vardenafil tablets (20 mg) were weighed and the average weight was calculated. The tablets were powder equivalent to 50 mg of active pharmaceutical ingredient (vardenafil) was transferred in to a 100 ml volumetric flask.

5.3 Risk of Priapism

Before taking vardenafil, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details. Do not take vardenafil unless it has been prescribed to you by a healthcare provider. Do not share vardenafil with other people, even if they have the same condition as you. Keep vardenafil out of the reach of children.

Drawing up the medication from the vial

Do not chew, cut, or crush vardenafil orally disintegrating tablets. Sexual activity can put extra strain on your heart, which may be unsafe for people with certain health problems, such as a recent heart attack. Talk to your healthcare provider to see if your heart is strong enough for sex. If you feel chest pain, dizziness, or nausea during sex, stop and contact your healthcare provider right away. Vardenafil does not protect against sexually transmitted infections, including HIV.