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Objective: To prepare ligustrazine pamoate (Lig-PAM) sustained-release nanosuspension (Lig-PAM-NSps) and determine its in vitro release characteristics. Methods: Lig-PAM was prepared by hydrophobic salt formation method and its physicochemical properties were characterized. Then, Lig-PAM-NSps was prepared by miniaturized medium grinding method. The prescription and preparation process of Lig-PAM-NSps were optimized by the single factor and orthogonal experiment with average particle size, polydispersity index (PDI) and stability coefficient (SI) as indicators. Lig-PAM-NSps was characterized, and its stability and in vitro release was also investigated. Results: The compound ratio of Lig-PAM prepared by Lig and PAM in the amount of 1:1 was (97.48 ± 0.04)%. Compared with Lig, the solubilities of Lig-PAM in water and simulated body fluids were decreased by 95.50% and 77.39%, respectively. Fourier transform infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRD) showed that the Lig and PAM formed Lig-PAM. The optimum prescription size of Lig-PAM-NSps was (585 ± 5) nm, PDI was (0.328 ± 0.015) and SI was (0.928 ± 0.012). The scanning electron microscopy (SEM) showed that Lig-PAM-NSps was spherical with uniform size distribution, and the particle size was about 600 nm and its physical stability was good within 60 d. The results of in vitro release showed that Lig-PAM-NSps had obvious sustained-release effect compared with Lig solution within 48 h, and showed the first-order release characteristics [ln(1-Q) = 0.153 67 t + 80.458 14, r = 0.998 26]. Conclusion: The preparation progress of Lig-PAM-NSps is stable and can release Lig slowly in vitro.
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Objective: To investigate the application characteristics of excipient copovidone in co-grinding process and the feasibility of co-grinding products for improving the dissolution of curcumin, using curcumin as a model drug in vitro. Methods: The prepared products were obtained by curcumin and various proportions (0%, 1%, 3%) of copovidone in co-grinding process, which were characterized by laser particle size analyzer, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X-ray powder diffraction (XRPD). The in vitro dissolution of milled products was evaluated in two media, and their accelerated stability was investigated. Results: In comparison with pure curcumin, the particle size of milled products decreased with the lower crystallinity by XRPD analysis, but the hygroscopicity and DSC thermograms showed no significant difference. Moreover, compared with pure curcumin, the products exhibited significant improvement of in vitro dissolution. Also, there was no significant difference in the dissolution behavior of products placed under the accelerated conditions (40 ℃, RH 75%) for three months, indicating their good stability. Conclusion: As a new excipient, copovidone could effectively enhance the dissolution of curcumin via co- grinding process. This study provided a feasible strategy for improving the solubility and even oral bioavailability of poorly soluble drugs.
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OBJECTIVE: To compare the in vitro dissolution of ursodeoxycholic acid capsules prepared by different grinding methods and screen the best grinding method. METHODS: Using the large cup method, HPLC was used to investigate the similarity of dissolution behaviors between the reference preparation Ursofalk® (the original drug) and the self-made ursodeoxycholic acid capsules in four dissolution media. The grinding method which obtained product with qualified similarity factor f2 was determined as the best technology. RESULTS: The ursodeoxycholic acid capsules made with raw material micronized by ball grinder for 3 min had similar dissolution curve to the original drug. CONCLUSION: Rational preparation process is established for ursodeoxycholic acid capsules.
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OBJECTIVES: We compared the effects of two different nano-sized calcium supplements (synthesized by wet-chemical method or the dry-grinding method of calcium carbonate) and one micro-sized calcium supplement (calcium carbonate) on intestinal absorption and bone turnover in 20 young women. MATERIALS & METHODS: This study was carried out with a three week cross-over design. The subjects ingested one of three different calcium supplements (1 dose of 500 mg Ca++) at 8 AM, which was repeated three times weekly. Serum and urine samples were collected before and after the calcium load using a time table (serum sampling 0, 2 hr, 4 hr, 8 hr after loading; urine sampling 0, 4 hr, 8 hr after loading). RESULTS: Serum ionized calcium and parathyroid hormone concentrations significantly changed in response to all calcium supplements loading, the difference among calcium supplements was not significant. However, the postload urinary excretion of calcium and the N-telopeptide/creatinine ratio were significantly different among three calcium supplement over time by repeated measured ANOVA. CONCLUSIONS: The results of this study suggest the effect of nano-sized calcium supplements synthesized by the wet-chemical method is superior to the other calcium supplements in intestinal calcium absorption and bone turn-over.
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Absorption , Calcium , Cross-Over Studies , Intestinal Absorption , Parathyroid HormoneABSTRACT
OBJECTIVE: To improve the dissolution rate of nitrendipine in vitro using co-grinding method.METHODS: Single-factor test was adopted to detect effect of phases of co-grinding,category of excipients (MCC,PVPk30,HPC,HPMC),time (0,10,20,30,40,50,60 min) of co-grinding and ratio of principal component to excipients (1 ∶ 1,1 ∶ 2,1 ∶ 3,1 ∶ 4,1 ∶ 5,1 ∶ 6,1 ∶ 7,1 ∶ 8,1 ∶ 9) on in vitro dissolution of nitrendipine power and tablet.RESULTS: The condition of co-grinding method was as follows: dual co-grinding phase,HPC or MCC as excipients,co-grinding time of 40 min,ratio of principal component to excipients was 1 ∶ 4.Accumulative dissolution rate of nitrendipine powder was more than 80% within 10 min and that of nitrendipine tablet was more than 80% within 40 min.CONCLUSION: Co-grinding method can improve the dissolution rate of poorly water-soluble nitrendipine in vitro under suitable condition.