Spray-Dried Lactose Composite Particles Containing an Ion Complex of Alginate-Chitosan for Designing a Dry-Coated Tablet Having a Time-Controlled Releasing Function

Abstract

Purpose. The properties of novel spray-dried lactose compositeparticles suitable for the coating filler of a dry-coated tablet having a longinduction period in drug release were investigated.

Methods. To prepare spray-dried composite particles containingalginate-chitosan complex (SD(L/AL-CS)), an aqueous solution of lactoseand sodium alginate and the acetic acid solution of chitosan wereconcomitantly fed into the rotary atomizer of a spray-dryer. Theformation of the alginate-chitosan complex was confirmed by measuring theweight of insoluble portion in the mixture of sodium alginate andchitosan solutions. The dissolution properties of the dry-coated tabletwere measured with the JP specified paddle method.

Results. The micromeritic properties of SD(L/AL-CS) were comparedto those of the SD composite particles of lactose-sodium alginate,having a good compacting property. The drug release profiles ofdry-coated tablet with SD(L/AL-CS) contained a long induction periodfollowed by a rapid drug release phase in the artificial intestinal fluid.The induction period for drug release to occur was increased with anincrease in the degree of deacetylation of chitosan and in the amountof chitosan in the formulation. The prolongation of induction periodwas attributed to the formation of an insoluble ion complex betweensodium alginate and chitosan in the composite particles, which couldform a rigid gel structure on the tablet surface.

Conclusions. A time-controlled release tablet was designed with thecomposite particles of lactose containing the alginate-chitosan ioncomplex. The induction period of the dry-coated tablet could be prolongedin order to deliver the drug to the colon by controlling the type andamount of chitosan formulated in the composite particles.