Ranitidine formulations

Terahertz pulse spectroscopy was used to observe the polymorphs of ranitidine hydrochloride.91 Sample preparation for this technique is the same as for Raman and FTIR spectroscopy and the data generated is complementary to Raman. Terahertz pulse spectroscopy provides information on the low-frequency intermolecular modes that are difficult to study with Raman due to the proximity of the laser excitation line. The authors concluded that this technique has many applications in pharmaceutical science including formulation, screening and stability studies. 

Because of the incredible success of Zantac, generic manufacturers were eager to enter the market with a generic version of ranitidine. Since the patent on Form 1 was set to expire in 1995, a generic manufacturer could conceivably enter the market with a Form 1 formulation without waiting for expiration of the Form 2 patent in 2002. Around... 

Form 2 impurities. The court ruled in favor of Novopharm. Novopharm was allowed to develop a generic formulation of Form 1 of ranitidine with a target market date of 1995, the expiration date of the Form 1 patent. 

Ranitidine suspension is formulated with alcohol as an excipient (along with many other suspensions). Metronidazole may react with the alcohol in the blood to cause a disulhram-like reaction leading to flushing and tachycardia. 

We used SEPIFILM LP in ranitidine core because this is a moisture-sensitive drug and can be a challenge to formulators because of its tendency to hydrolyze when exposed to humidity and/or high temperatures. 

Excipients such as mannitol can affect small intestinal transit, which in turn can affect the absorption of certain drugs. Oral solutions are rarely likely to fall short of bioequivalence relative to solid oral formulations, although during the development of a ranitidine effervescent oral solution dosage form containing sodium acid pyrophosphate (SAPP), a marked decrease in absorption was observed in the extent of ranitidine absorption from the liquid formulation relative to the conventional oral tablet. The formulation contained 150 mg ranitidine with 1132 mg SAPP together with 1.5 MBq hndium chloride solutions. Small intestinal transit time was decreased to 56% in the presence of the excipient. The rapid small intestinal transit associated with an excipient of a solution dosage form resulted in a decreased extent of ranitidine absorption. " ... 

Bismuth salts are still in use. Tripotassium dicitrato-bismuthate and bicitropeptide (a bismuth-peptide complex) are used in the eradication of Helicobacter pylori in combination with antibiotics (SEDA-21,233) (1 ), and ranitidine bismuth citrate is used to treat peptic ulcer (5). Bismuth salicylates are used in other intestinal diseases, such as microscopic colitis (6,7) and collagenous colitis (8). Bismuth subnitrate plus iodoform is used to pack surgical cavities. Bismuth oxide and bismuth subgallate are found in some topical formulations that are used for treating hemorrhoids. Bismuth is also used topically as a bacteriostatic. 

Fraser IM, Buttoo KM, Walker SE, Stewart JH, Babul N. Effects of cimetidine and ranitidine on the pharmacokinetics of a chronotherapeutically formulated once-daily theophylline preparation (Uniphyl). Clin Ther 1993 15(2) 383-93. 

Povidone K 25 and povidone K 30 are very good binders for effervescent tablets, as they dissolve rapidly in water to form a clear solution. This particularly applies to effervescent vitamin tablets, e.g. ascorbic acid tablets [368 b]. Tables 65 and 66 give formulations for ranitidine effervescent tablets and multivitamin effervescent tablets as typical examples that were developed on a laboratory scale. For the granulation of multivitamin preparations, it is always preferable to use a fluidized bed. 

AAS and AFS are used to detect metals in environmental samples in both trace and major concentrations. Analysis of metals like lead, mercury and cadmium in various samples such as tuna fish soils , mushrooms and shellfish is very common. AAS has been reported for the determination of drugs such as bromhexine, flunarizine and ranitidine hydrochlorides in pharmaceutical formulations down to concentrations of <2pg/mL . AAS has been used to analyse cadmium and lead in blood samples . The concentration ranges were 0.20-1.73 ppb and 12.0-65.7 ppb for cadmium and lead respectively. The techniques of AAS and AFS are also very popular in the analysis of herbal medicines - . ... 

Khalil, S., Ibrahim, S.A., Zedan, F.l. and Abd-El-Monem, M.S. (2005) AAS determination of bromhexine, flunarizine and ranitidine hydrochlorides in pharmaceutical formulations Chemia Analityczna (Warsaw, Poland), 50 (5), 897-904. 

Theoretically, it is unlikely that aqueous pharmaceutical formulations are going to be amenable to radiation sterilization. Consider the drug ranitidine (molecular weight of 314) in 1% aqueous solution ... 

Didanosine 375 mg (buffered saehet preparation) was given to 12 HIVpositive subjeets either alone, or 2 hours after a single 150-mg dose of ranitidine. The didanosine AUC was inereased by 14% by the ranitidine. The reason for this effeet is not known but the ranitidine possibly enhaneed the effeets of the eitrate-phosphate buffer with whieh the didanosine sachet was formulated. The ranitidine AUC was reduced by 16% for reasons that are not understood, but it is possible that antacids (such as the citrate-phosphate buffer) reduce the absorption of ranitidine (see H2-receptor antagonists + Antacids , p.%6). 

A method was developed and validated using a low pH buffer for the determination of ranitidine and potential related impurities in bulk dmg and formulations [194], This method gave detection limits of 0.03% diamine, 0.04% oxime, 0.1% Bis, and 0.24% nitroacetamide but importantly, it detected a number of peaks, which were not resolved by either HPLC or TLC. 

A dramatic improvement in stability to hydrolysis has been shown in the case of ranitidine (Figure 4). Formulations of ranitidine hydrochloride are known to have instability toward humidity and pH. Under test conditions of 50 °C at pH 1.5, the stabihty of ranitidine is extended to beyond two weeks in the presence of a slight excess of Q[7] with no decomposition compared to four days without Q[7] (50% decomposition). ... 

The receptor antagonists are water-soluble, neutral-pH, stable compounds that can readily be formulated as solutions ready to inject. Given their stability, they can be given either as bolus or continuous infusion. The liquid formulations can also be administered orally via nasogastric tube. Both methods have been used. Cimetidine, ranitidine, nizatidine, and famotidine are all available as IV solutions, and little difference exists between these drugs in terms of acid control with IV administration. Several studies have reported that continuous infusion gives the best data in terms of control of acid secretion. Unfortunately, relatively few controlled clinical trials have been performed on the effectiveness of many of these solutions. 

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