Ravindra W. Tejwani

Study of Phase Behavior of Poly(ethylene glycol)–Polysorbate 80 and Poly(ethylene glycol)–Polysorbate 80–Water Mixtures

Mixtures of poly(ethylene glycols) (PEGs) with polysorbate 80 are often used to dissolve poorly water-soluble drugs in dosage forms, where polysorbate 80 helps either in enhancing dispersion or in inhibiting precipitation of drugs once the solution is mixed with water. Binary phase diagrams of polysorbate 80 with several low molecular weight PEGs and a ternary phase diagram of polysorbate 80 with PEG 400 and water are presented. Two phases were observed in the binary mixtures when the concentration of PEG 200, PEG 300, PEG 400, or PEG 600 was >55%(w/w). The miscibility of the binary mixtures increases with an increase in temperature; the upper consolute temperatures of PEG 200-polysorbate 80, PEG 300-polysorbate 80, PEG 400-polysorbate 80, and PEG 600-polysorbate 80 mixtures were 100, 85, 75, and 40 degrees C, respectively. The upper consolute temperature of PEG 1000-polysorbate 80 could not be determined because the melting temperature of the mixtures is approximately 40 degrees C and the consolute temperature appeared to be less than this temperature. The decrease in upper consolute temperature with an increase in PEG molecular weight indicated a greater miscibility of the two components. In the ternary system, phase separation of polysorbate 80 was observed when the concentration of PEG 400 was >50-60 % (w/w), possibly because of the high exclusion volume of PEG 400.

Recommendations for the Assessment of Blend and Content Uniformity: Modifications to Withdrawn FDA Draft Stratified Sampling Guidance

IntroductionThe following paper describes the International Society for Pharmaceutical Engineering (ISPE)-sponsored Blend Uniformity and Content Uniformity Group’s proposed modifications to the withdrawn FDA draft guidance document for industry “Powder Blends and Finished Dosage Units—Stratified In-Process Dosage Unit Sampling and Assessment.” The modifications targeted FDA’s primary concerns that led to the withdrawal of the draft guidance document, which were insufficient blend uniformity testing and that a one-time passing of the criteria stated in USP General Chapter <905> Uniformity of Dosage Units testing lacks confidence to ensure the content uniformity of a batch.MethodThe Group’s approach discusses when triplicate blend samples should be analyzed and the importance of performing variance component analysis on the data to identify root causes of non-uniformity. The Group recommends the use of statistically based approaches, acceptance criteria, and sampling plans for assessing content uniformity for batch release that provide increased confidence that future samples drawn from the batch will comply with USP <905>. Alternative statistical approaches, sampling plans, and acceptance criteria, including modern analytical method (e.g., process analytical technology (PAT)) sampling plans, may be substituted for those mentioned in this paper, with justification. This approach also links blend and content uniformity testing to the three stages of the life cycle process validation approach.ConclusionA framework for the assessment of blend and content uniformity that provides greater assurance of passing USP <905> is presented.

Assessment of Blend and Content Uniformity. Technical Discussion of Sampling Plans and Application of ASTM E2709/E2810

ABSTRACTIntroductionThe FDA withdrew the draft guidance document for industry “Powder Blends and Finished Dosage Units—Stratified In-Process Dosage Unit Sampling and Assessment.” An FDA’s primary concern was a lack of confidence that the results from USP <905> Uniformity of Dosage Units testing ensure the content uniformity of a batch. ISPE sponsored the Blend Uniformity and Content Uniformity Group (referred to as Group), which was formed in August 2013 to discuss approaches to assess blend and content uniformity. Modifications to the withdrawn draft stratified sampling guidance document are proposed by the Group for the assessment of adequacy of powder mix and content uniformity of the finished product in “Recommendations for the Assessment of Blend and Content Uniformity: Modifications to Withdrawn FDA Draft Stratified Sampling Guidance,” accepted by J Pharm Innov, 2014. Specific statistical methodologies to construct acceptance criteria were not recommended in the paper. This paper provides an example and technical discussion of a statistical approach that can be inserted into the framework described in the Group’s paper. There may be other approaches to sampling plans, statistical analysis, and acceptance criteria that are acceptable to demonstrate content uniformity.MethodASTM E2709, “Standard Practice for Demonstrating Capability to Comply with an Acceptance Procedure” and E2810, “Standard Practice for Demonstrating Capability to Comply with the Test for Uniformity of Dosage Units” for demonstrating dosage unit uniformity can be used to evaluate content uniformity. These standards are discussed and applied to the sampling plans given in the Group’s paper. The method can provide with a high level of confidence that samples from a lot will have a high probability of passing the USP UDU test. The methodology can be used to evaluate content uniformity data based on a sampling plan that tests either one or more than one dosage unit from each of multiple locations throughout the lot. An acceptance limit table based on sample means and standard deviations can be generated that is easy for the user to apply to content uniformity results.ResultsOperating characteristic (OC) curves for process qualification and continued process verification/routine lot release sampling plans are presented and compared along with the USP UDU OC curve. The process qualification criteria/sampling plans are shown to be “conservative” compared to the USP UDU test. A two-stage tiered plan is shown that could be used during continued process monitoring/routine release.ConclusionThe ASTM E2709/E2810 methodology provides acceptance criteria for several sampling plans that could be used for the assessment of content uniformity during process qualification and continued process monitoring/routine release. Passing the acceptance criteria can assure with a high level of confidence that a lot can meet the USP UDU test.

Discovery and preclinical studies of 5-isopropyl-6-(5-methyl-1,3,4-oxadiazol-2-yl)-N-(2-methyl-1H-pyrrolo[2,3-b]pyridin-5-yl)pyrrolo[2,1-f][1,2,4]triazin-4-amine (BMS-645737), an in vivo active potent VEGFR-2 inhibitor.

We report herein a series of substituted N-(1H-pyrrolo[2,3-b]pyridin-5-yl)pyrrolo[2,1-f][1,2,4]triazin-4-amines as inhibitors of vascular endothelial growth factor receptor-2 tyrosine kinase. Through structure-activity relationship studies, biochemical potency, pharmacokinetics, and kinase selectivity were optimized to afford BMS-645737 (13), a compound with good preclinical in vivo activity against human tumor xenograft models.

Metabolism of 5-isopropyl-6-(5-methyl-1,3,4-oxadiazol-2-yl)-N-(2-methyl-1H- pyrrolo(2,3-b)pyridin-5-yl)pyrrolo(2,1-f)(1,2,4)triazin-4-amine (BMS-645737): Identification of an Unusual N-Acetylglucosamine Conjugate in the Cynomolgus Monkey

5-Isopropyl-6-(5-methyl-1,3,4-oxadiazol-2-yl)-N-(2-methyl-1H-pyrrolo[2,3-b]pyridin-5-yl)pyrrolo[2,1-f][1,2,4]triazin-4-amine (BMS-645737) is a potent and selective vascular endothelial growth factor receptor-2 antagonist. In this study, liquid chromatography/tandem mass spectrometry and NMR were used to investigate the biotransformation of BMS-645737 in vitro and in the cynomolgus monkey, dog, mouse, and rat. Metabolic pathways for BMS-645737 included multistep processes involving both oxidation and conjugation reactions. For example, the 2-methyl-1H-pyrrolo moiety underwent cytochrome P450-catalyzed hydroxylation followed by oxidation to a carboxylic acid and then conjugation with taurine. Alternatively, the 5-methyl-1,3,4-oxadiazol-2-yl moiety was metabolized by hydroxylation and then conjugation with sulfate. The pyridin-5-yl group underwent direct glucuronidation in hepatocytes (dog, monkey, human) and conjugation with N-acetylglucosamine in the monkey. Conjugation with glutathione and processing along the mercapturic acid pathway was a minor metabolic pathway in vivo, although BMS-645737 did not form conjugates in the presence of glutathione-supplemented liver microsomes. Other minor biotransformation pathways included oxidative dehydrogenation, dihydroxylation, and hydrolytic opening of the oxadiazole ring followed by either deacetylation or hydrolysis of the resulting diacyl hydrazide. Whereas previous studies have shown the formation of N-acetylglucosamine conjugates of alcohols, arylamines, and other small molecules, this report describes the biotransformation of a heterocyclic aromatic amine via direct conjugation with N-acetylglucosamine.

Bioequivalence and food effect of heat-stressed and nonheat-stressed dapagliflozin 2.5- and 10-mg tablets

Physical storage of formulations may result in physical composition changes that affect pharmacokinetics. Dapagliflozin, an oral sodium-glucose cotransporter 2 inhibitor used for type 2 diabetes mellitus, stored under prolonged exposure to heat converts crystalline dapagliflozin to an amorphous form. Bioequivalence of the amorphous to crystalline form and food effects of each form in the 2.5-mg formulation are unknown. Two open-label, crossover, single-dose studies in healthy participants assessed pharmacokinetics for heat-stressed (HS) and non-heat-stressed (NH) dapagliflozin 10-mg (study 1, N=29, fasted+HS food effect) and 2.5-mg (study 2, N=28, fasted+HS and NH food effect) tablets. The 90% confidence intervals for geometric mean ratios of area under the concentration-time curve (AUC) and peak concentration (Cmax) for HS 2.5- and 10-mg tablets were within 80-125%, indicating bioequivalence. In the fed vs. fasted state for 2.5-mg and 10-mg HS tablets, AUCs were similar, time to Cmax was prolonged by 1.25h, and Cmax decreased by approximately 50%. No serious adverse events were reported. Given that dapagliflozins efficacy is dependent upon AUC, it was concluded that HS and NH dapagliflozin tablets are bioequivalent in 2.5- and 10-mg doses with no clinically meaningful food effect for either form.