Primaquine phosphate tablets

Primaquine phosphate tablets contain not less than 93% and not more than 107% of the labeled amount of C15H21N3O2H3PO4. 

Katori et al [84] used a high performance liquid chromatographic method for the determination of primaquine phosphate tablets. Chromatography on a TSK Gel-4 (octadecylsilanized) column was used to determine the active ingredient in tablets and injections for treating tropical diseases. The mobile phase used is 26% acetonitrile in 0.05-M pH-3 phosphate buffer and the drug was detected at 260 nm. The peak area and peak height reproducibilities were <1.69%, and results compared well with those of other methods. 

Mefloquine hydrochloride tablets 250 mg. Primaquine phosphate tablets 7.5 or 15 mg. Proguanil hydrochloride tablets 100 mg. 

Digest a quantity of finely powdered tablets, equivalent to about 25 mg of primaquine phosphate, with 10 mL of water for 15 min, and filter. 

Weigh and finely powder not less than 30 tablets. Weigh accurately a portion of the powder, equivalent to about 700 mg of primaquine phosphate, and transfer to a... 

Abou-Ouf et al. [16] described a spectrophotometric method for the determination of primaquine phosphate in pharmaceutical preparation. Two color reactions for the analysis of primaquine phosphate dosage form, which are based on 2,6-dichlor-oquinone chlorimide and l,2-naphthoquinone-4-sulfonate, were described. The reactions depend on the presence of active centers in the primaquine molecule. These are the hydrogen atoms at position 5 of the quinoline nucleus and the primary amino group of the side chain. The method was applied to tablets of primaquine phosphate and a combination of primaquine phosphate and amodiaquine hydrochloride. 

Hassan et al [18] used a spectrophotometric method for the simultaneous determination of primaquine with amodiaquine mixtures in dosage forms. Crushed tablets containing primaquine phosphate and amodiaquine hydrochloride were extracted with 0.1 M hydrochloric acid, and the mixture was filtered. A portion of the filtrate was diluted with 0.1 M hydrochloric acid, and the absorbance of this solution was measured at 282 and 342 nm against hydrochloric acid. 

Vishwavidyalaya et al. [22] used a difference-spectrophotometric method for the estimation of primaquine phosphate in tablets. One portion of powdered tablets, equivalent to 7.5 mg of primaquine phosphate, was extracted with hydrochloric acid-potassium chloride buffer (pH 2) and a second portion was extracted with phosphate buffer (pH 10). Primaquine phosphate was determined from the difference in absorbance of the acid and alkaline extracts at 254.2 nm. The calibration graph was rectilinear from 2 to 14 pg/mL of primaquine phosphate. Recovery was 98.6% and no interference was observed from excipients. Results compared with those by the British Pharmacopoeial method. 

Min et al. [23] determined primaquine phosphate, in tablets, by an ultraviolet spectrophotometric method. Sample was treated with 0.01 M hydrochloric acid and the resulting solution (500 pg/mL) was diluted to 50 mL with 0.01 M hydrochloric acid. The absorbance of the solution was measured at 265 nm versus a reagent blank. Beer s law was obeyed from 8 to 20 pg/mL of primaquine phosphate. Recovery was 100.2% (n = 5) and the coefficient of variation was 0.5%. Results were consistent with those obtained by a pharmacopoeial method. 

Talwar et al. [26] described a difference spectrophotometric method for the estimation of primaquine phosphate in tablets. The method is based on the... 

Cheng et al. reported the use of a synchronous fluorimetric method for the determination of primaquine in two-component antimalarial tablets [31]. Ground tablets were dissolved in water and the mixture was filtered. The fluorescence intensities of chloroquine phosphate and primaquine phosphate, in the filtrate, were measured at 380 nm (excitation at 355 nm) and 505 nm (excitation at 480 nm), respectively. The calibration graphs were linear from 1 to 8 pg/mL of chloroquine phosphate and 10 to 110 pg/mL of primaquine phosphate. The mean recoveries were 98.2-101.49% and the relative standard deviations were 2.23%. 

John et al. [37] described a colorimetric method for the estimation of primaquine phosphate. Sample solutions of different dilutions (0.15-0.6 mL) of the drug (6-24 pg/mL) were treated with 5 mL of 1% cerric ammonium sulfate in dilute nitric acid and made up to 25 mL with water. The absorbance of the resulting light purple solution was measured at 480 nm after similar 30 min. Beer s law was obeyed from 5 30 pg/mL of primaquine phosphate. The method is applicable to bulk formulations in addition to tablets and capsule formulation. 

Sastry et al. [41] used a new spectrophotometric method for the estimation of primaquine, using 3-methylbenzothiazolin-2-one hydrazone. An aqueous extract of the sample of powdered tablets (containing 50 pg/mL of primaquine phosphate was mixed with 1 mL each of aqueous 8.5 mM 3-methylbenzothiazolin-2-one hydrazone and 11.84 mM CelV (in 0.72 M sulfuric acid), the mixture was diluted to 10 mL, and the absorbance was measured at 510 nm versus a reagent blank. Beer s law was obeyed for 0.7-12 pg/mL of the drug and for 50 pg, the coefficient of variation was 0.52%i (n = 8). Other antimalarials and pharmaceutical adjuvants did not interfere. 

Rao et al. [45] determined primaquine phosphate, in pharmaceutical dosage forms, by using a colorimetric method. Powdered tablets containing the equivalent of 100 mg of primaquine phosphate were heated with 25 mL of water for 10 min, the solution was cooled and filtered, and 10 mL portion of the filtrate was diluted 10-fold with water. A 5-mL portion of this solution was mixed with 5 mL of pH 5 buffer solution, 1 mL of 0.08%. amidopyrine solution in aqueous 95% alcohol and 2 mL of aqueous 0.1% sodium periodate. After 10 min, 0.5 mL of aqueous sodium metabisulfite solution was added and the absorbance was measured at 580 nm. Beer s law was obeyed between 4 and 43 pg/mL of primaquine phosphate. Recoveries were quantitative. 

Rao et al. [46] reported the use of a spectrophotometric method for the determination of primaquine phosphate with ninhydrin. Standard solution of 0.01% primaquine phosphate solution (3 mL) or solution prepared from the drug or its tablets was mixed with 2 mL of water, 5 mL of 2-methoxyethanol and then with 4 mL of ninhydrin reagent. The mixture was boiled for 35 min, and, after cooling and dilution to 25 mL with water, the absorbance was measured at 570 nm versus a reagent blank. Beer s law was obeyed from 4 to 20 pg/mL with recoveries of 99.4— 100.2% for 25 mg of primaquine phosphate. 

El-Kommos and Emara [47] determined primaquine and other secondary aromatic amines pharmaceuticals by a spectrophotometric method using 4-dimethyl amino cinnamaldehyde. The reaction of the reagent with primaquine and with the other amines was investigated. Powdered tablets were extracted with methanolic 0.1 M perchloric acid. The extract was mixed 1 1 with methanolic 0.2% of 4-dimethyl amino cinnamaldehyde and the mixture was diluted with methanol before measurement of the absorbance at 670 nm for primaquine phosphate. Beer s law was obeyed for 2-20 pg/mL of primaquine. The pink and green color formed with primaquine was stable for at least 24 h. Recoveries were good. Amodiaquine did not interfere with the determination of primaquine. 

Ibrahim et al. [49] described a spectrophotometric method for the determination of primaquine and other antimalarial agents in pharmaceuticals. Powdered tablet or ampule contents containing 25 mg of primaquine phosphate, was dissolved in water and the solution was made alkaline with 6 M ammonia before extraction with chloroform. The extract was evaporated to dryness and the residue was dissolved in acetonitrile. A portion of the solution was mixed with 0.04% tetracyanoethylene solution in acetonitrile and diluted to volume with acetonitrile. After 10 min, the absorbance was measured at 415 nm for primaquine. Beer s law was obeyed from 2 to 12 mg/mL. The results agreed well with those of the United State Pharmacopoeia XX method. 

Sastry et al. [50] estimated primaquine in its tablet formulation. Powdered tablets equivalent to 100 mg of primaquine phosphate were dissolved in water, filtered, and filtrate was diluted to 100 mL with water. Portions of the solution were shaken with 3 mL of 5 mM brucine-0.16 M sulfuric acid, 1.5 mL of 5 mM sodium periodate and 2 mL of 1.2 M sulfuric acid and diluted to 9 mL with water. The solution was set aside for 20 min in a boiling water bath, cooled, and diluted to 10 mL with water. The absorbance was measured at 510 nm versus a reagent blank. Beer s law was obeyed from 20 to 140 pg/mL of primaquine phosphate. The coefficient of variation was 1.56% (n = 8). Recovery was 99.2%. 

Primaquine phosphate 26.3-mg tablet Pyrantel pamoate (Antiminth) 50-mg/mL suspension Malaria (P. vivax) (P. ovale) Pinworm Hookworm Gl Nausea, abdominal pain CNS Mental depression Gl Anorexia, nausea, abdominal cramps, diarrhea CNS Headache, dizziness In G6PD deficiency can cause hemolysis 9, 10-13, 23, 24,25 9, 24, 9, 99... 

Primaquine phosphate USP. Tablets marketed in the U.S. contain 15 mg primaquine base per tablet (this may vary elsewhere) doses below are expressed as primaquine base. Primaquine may be used in special circumstances, such as when preferred agents cannot be tolerated or for multidrug-resistant P. falciparum. This should be done with caution and in consultation with malaria experts, such as those available through the CDC. The adult dose is 30 mg base (2 tablets) daily starting several days before exposure and continued for 7 days after exposure. The same regimen at a dose of 0.6 mg/kg base is used for children. Primaquine is contraindicated in G6PD deficiency or pregnancy see text). 

A simple, sensitive, and selective method for the determination of amodiaquine hydrochloride in tablets has been developed. It is based on a color reaction with chloramine-T in the pH range 7.4- 8.0. The chromogen is extracted with chloroform and the absorbance is measured at 442 nm. Beer s law is obeyed in the concentration range 1-200 n%/. The coefficient of variation has been found to be 0.64% and the recovery ranges between 100.3 and 102.5%. Chloroquine phosphate or primaquine phosphate do not interfere with the method (29). 

There have been 2 recent reports of acute porphyria developing following ingestion of chloroquine. In one case (8 -) an elderly patient treated for cutaneous porphyria tarda received 10 times the prescribed dose and suffered a severe, acute porphyric crisis as a result. The other report (9 -) referred to a 39-year-old woman who developed acute porphyria after a single dose of a combination chloroquine-primaquine tablet for malaria prophylaxis. The dose of chloroquine phosphate ingested by this patient was 300 mg. 

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