Development and characterization of sponge-like acyclovir ocular minitablets

Figures & data

Figure 1.  Minitablet with a dimension of 0.4 × 0.2 mm in comparison to a conventional oral tablet having a diameter of 12 mm.

Table 1.  Physical characteristics of minitablets prepared from different polymers (M ± SD, n = 3).

Formula	Swelling Index(1 h)	Viscosity (cps)0.5 rpm G =1	MDR^aμg/ml/min	Bioadhesion force (N)
1% chitosan	3.5 (± 1.23)	1,179 (± 124)	0.74 (± 0.48)	0.507 (± 0.021)
2% NaCMC	23.8 (± 0.76)	12,960 (± 315)	1.45 (± 0.31)	0.851 (± 0.032)
mix.	8.2 (± 0.69)	16,890 (± 225)	1.66 (± 0.26)	0.621 (± 0.015)
1% xanthan	15.8 (± 0.11)	2,357 (± 108)	1.38 (± 0.37)	0.355 (± 0.024)
1% Carbopol	32.2 (± 1.39)	52,650 (± 188)	3.63 (± 0.76)	1.157 (± 0.033)
1% HPMC	11.2 (± 1.55)	2,554 (± 89)	1.80 (± 0.06)	0.062 (± 0.042)
1% NaCMC	20.4 (± 0.82)	785 (± 54)	5.09 (± 0.22)	0.368 (± 0.017)

^a MDR = Mean dissolution rate.

Figure 2.  Water uptake of minitablets prepared from different polymers. Error bars represent SD (n = 3).

Figure 3.  Release of acyclovir from minitablets prepared from different polymers. Error bars represent SD (n = 3).

Table 2.  Kinetic parameters of the prepared ocular minitablets.

Components	R^2			Mechanism	t^1/2	n
	Zero Order	First Order	Diffusion
2%NaCMC	0.9638	0.9807	0.9776	Zero Order	28.38	0.4329	fickian
1%chitosan	0.8792	0.9673	0.9724	Diffusion	65.41	0.7011	anomalous
mix.	0.9431	0.9880	0.9917	Diffusion	16.31	0.338	fickian
1%xanthan	0.9802	0.9774	0.9978	Diffusion	25.53	0.9017	anomalous
1%Carbapol	0.9839	0.9753	0.9996	Diffusion	24.90	0.3938	Fickian
1%HPMC	0.9993	0.9569	0.9856	Zero Order	18.70	1.1262	super case II

Figure 4.  Permeation of acyclovir into cornea of rabbit from chitosan 1% minitablet and from Zovirax^® eye ointment. Error bars represent SD (n = 3).

Figure 5.  (a) Infected eye of Bokhara Trumpeter Pigeon, (b) Application of chitosan minitablet into the infected eye, and (c) Complete recovery of the infection after 48 h.