Our previous work (Mol Pharm, 20 (2023) 3427) showed that crystalline excipients, specifically anhydrous dibasic calcium phosphate (DCPA), facilitated the dehydration of carbamazepine dihydrate (CBZDH) and the formation of an amorphous product phase during the mixing stage of continuous tablet manufacturing. Understanding the mechanism of this excipient-induced effect was the object of this study. Blending with DCPA for 15 min caused pronounced lattice disorder in CBZDH.
View Article and Find Full Text PDFPoloxamer 188 (P188) was hypothesized to be a dual functional excipient, (i) a stabilizer in frozen solution to prevent ice-surface-induced protein destabilization and (ii) a bulking agent to provide elegant lyophiles. Based on X-ray diffractometry and differential scanning calorimetry, sucrose, in a concentration-dependent manner, inhibited P188 crystallization during freeze-drying, while trehalose had no such effect. The recovery of lactate dehydrogenase (LDH), the model protein, was evaluated after reconstitution.
View Article and Find Full Text PDFIn recent years, continuous tablet manufacturing technology has been used to obtain regulatory approval of several new drug products. While a significant fraction of active pharmaceutical ingredients exists as hydrates (wherein water is incorporated stoichiometrically in the crystal lattice), the impact of processing conditions and formulation composition on the dehydration behavior of hydrates during continuous manufacturing has not been investigated. Using powder X-ray diffractometry, we monitored the dehydration kinetics of carbamazepine dihydrate in formulations containing dibasic calcium phosphate, anhydrous (DCPA), mannitol, or microcrystalline cellulose.
View Article and Find Full Text PDFThe review summarizes the current state of knowledge of mannitol as an excipient in lyophilized injectable small and large molecule formulations. When compared with glycine, the physicochemical properties of mannitol make it a desirable and preferred bulking agent. Though mannitol is a popular bulking agent in freeze-dried formulations, its use may pose certain challenges such as vial breakage or its existence as a metastable crystalline hemihydrate in the final cake, necessitating appropriate mitigation strategies.
View Article and Find Full Text PDFWhile arginine hydrochloride (ArgHCl) has emerged as a potential stabilizer of protein drugs in liquid formulations, the purpose of this manuscript was to evaluate its stabilization potential in frozen solutions. The phase behavior of frozen ArgHCl solutions was investigated by differential scanning calorimetry and low temperature powder X-ray diffractometry. The aggregation of β-galactosidase was evaluated following freeze-thaw cycling in ArgHCl solutions with and without mannitol.
View Article and Find Full Text PDFThis review aims to provide an overview of the current knowledge on protein stabilization during freezing and freeze-drying in relation to stress conditions commonly encountered during these processes. The traditional as well as refined mechanisms by which excipients may stabilize proteins are presented. These stabilizers encompass a wide variety of compounds including sugars, sugar alcohols, amino acids, surfactants, buffers and polymers.
View Article and Find Full Text PDFThe aggregation behavior of two model proteins- i) bovine serum albumin (BSA) and ii) β-galactosidase (β-gal), was investigated by micro-flow imaging (MFI) during freeze-thaw cycling in phosphate buffered solutions. The pH shift was measured upon cooling the solutions from 20 to -25 °C. When the buffer concentration was 100 mM, cooling caused a pH decrease of 3.
View Article and Find Full Text PDFThe purpose of this study was to investigate the phase behavior of cyclophosphamide (CPA) during various stages of lyophilization, with special emphasis on obtaining crystalline CPA monohydrate (CPA-MH) in the lyophilized product. Subambient differential scanning calorimetry and low-temperature X-ray diffractometry (LTXRD) were used to study the phase behavior of CPA solution (3.7% w/v).
View Article and Find Full Text PDFPurpose: Drug-polymer miscibility has been proposed to play a critical role in physical stability of amorphous solid dispersions (ASDs). The purpose of the current work was to investigate the role of drug-polymer miscibility on molecular mobility, measured as enthalpy relaxation (ER) of amorphous irbesartan (IBS) in ASDs.
Methods: Two polymers, i.
Mannitol is a commonly used bulking agent in lyophilized formulations. It can crystallize into multiple solid forms during lyophilization thereby exhibiting phase heterogeneity and variability in product performance. In this manuscript, we studied the effect of cyclophosphamide (CPA), an anticancer drug, on the solid form of mannitol during lyophilization from aqueous solutions.
View Article and Find Full Text PDFIn this study, the effect of four non-crystallizing sugars, namely fructose, trehalose, sucrose and raffinose, was assessed on the crystallization of gemcitabine hydrochloride (GHCl) in frozen solutions. Aqueous solutions containing GHCl (50 mg/mL) and a sugar at varying concentrations (10-60 mg/mL) were frozen in situ in DSC and analyzed in the subsequent heating run. Crystallization propensity of GHCl was quantified in terms of reduced crystallization temperature (RCT) as a function of sugar type and concentration.
View Article and Find Full Text PDFThe effect of tert-butyl alcohol (TBA) on isothermal crystallization kinetics of gemcitabine hydrochloride (GHCl) in frozen aqueous solutions was assessed by cold-stage microscopy. Addition of TBA (0%-5%, w/w) increased the value of Johnson-Mehl-Avrami rate constant (1.3-33.
View Article and Find Full Text PDFThe purpose of this study was to evaluate the differential effect of buffering agents on the crystallization of gemcitabine hydrochloride (GHCl) in frozen solutions. Four buffering agents, viz. citric acid (CA), malic acid (MA), succinic acid (SA) and tartaric acid (TA) were selected and their effect on GHCl crystallization was monitored using standard DSC and low temperature XRD.
View Article and Find Full Text PDFUnlabelled: Curcumin has shown to be effective against various diabetes related complications. However major limitation with curcumin is its low bioavailability. In this study we formulated and characterized self nano emulsifying drug delivery system (SNEDDS) curcumin formulation to enhance its bioavailability and then evaluated its efficacy in experimental diabetic neuropathy.
View Article and Find Full Text PDFThe clinical utility of curcumin (CRM) is limited due to its poor oral bioavailability. Lipid based oral formulations (LBOFs) are emerging as useful oral drug delivery systems for 'difficult to deliver' molecules like CRM. In present study, we report novel Type IV LBOF for CRM using Gelucire 44/14, Labrasol, Vit.
View Article and Find Full Text PDFNumerous publications have reported the significant pharmacodynamic activity of Curcumin (CRM) despite low or undetectable levels in plasma. The objective of the present study was to perform a detailed pharmacokinetic evaluation of CRM after the oral administration of a highly bioavailable lipidic formulation of CRM (CRM-LF) in human subjects. Cmax, Tmax and AUC0-¥ were found to be 183.
View Article and Find Full Text PDFThe aim of the present study was to study the oral bioavailability of seven different formulations of curcumin (CRM). CRM formulations viz. aqueous suspension, micronized suspension, nanosuspension, amorphous solid dispersion, hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion complex, combination with piperine, and spray-dried CRM-milk composite were compared for oral bioavailability in male Sprague-Dawley rats at a CRM dose of 250 mg/kg body weight using a validated high-performance liquid chromatography method.
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