Preparation of Naomaiqing freeze-drying for injection

Objective To prepare Naomaiqing freeze-drying for injection and investigate the stability of borneol in the process of lyophilization.Methods Polyoxyethylene castor oil(EL-40) or hydroxypropyl-β-cyclodextrin(HP-β-CD) were selected as a solubilizer for borneol, and then were mixedwith solution of danshen(Salvia miltiorrhiza) and sanqi(Panax notoginseng) extracts.Naomaiqing injection was prepared by freeze-drying, and borneol was determined by GC.Results At the ratio beyond 1:12 of borneol and polyoxyethylene castor oil, a clear solution was obtained, while for borneol and hydroxypropyl-β-cyclodextrin the ratio of was 1:18 and 1:20.Mannitol as a lyoprotectant, the freeze-drying samples exhibited good appearance and light yellow color.With different danshen extracts, using the same solubilizer(polyoxyethylene castor oil,EL-40), the loss of borneol was different obviously.In comparison between danshen extracts which was refined by macroporous resin and danshen extract which was refined by organic solution extraction, and the later exhibited a higher content of borneol.Using the same solubilizer(HP-β-CD) with different danshen extracts, the content of borneol was 95.1%, 94.7%, respectively.Conclusion Preparation of freeze-drying samples by adopting HP-β-CD as a slubilizer and danshen extract which is refined by macroporous resin, the samples exhibits loose texture and satiated appearance, and higher content of borneol.